AU2015275236B2

AU2015275236B2 - Electron beam layer manufacturing

Info

Publication number: AU2015275236B2
Application number: AU2015275236A
Authority: AU
Inventors: Scott Stecker
Original assignee: SCIAKY Inc
Current assignee: SCIAKY Inc
Priority date: 2009-09-17
Filing date: 2015-12-22
Publication date: 2017-07-20
Anticipated expiration: 2030-09-16
Also published as: AU2015275236A1

Abstract

A process and apparatus for free form fabrication of a three-dimensional work piece comprising (a) feeding raw material in a solid state to a first predetermined location; (b) depositing the raw material onto a substrate as a molten pool deposit under a first processing 5 condition; (c) monitoring the molten pool deposit for a preselected condition; (d) comparing information about the preselected condition of the monitored molten pool deposit with a predetermined desired value for the preselected condition of the monitored molten pool deposit; (e) solidifying the molten pool deposit; (f) automatically altering the first processing condition to a different processing condition based upon information obtained from the comparing step (d); [0 and repeating steps (a) through (f) at one or more second locations for building up layer by layer a three-dimensional work piece. The apparatus is characterized by a detector that monitors a preselected condition of the deposited material and a closed loop electronic control device for controlling operation of one or more components of the apparatus in response to a detected condition by the detector.

Description

2015275236 22 Dec 2015 P/00/011 Regulation 3.2 Australia

Patents Act 1990

COMPLETE SPECIFICATION STANDARD PATENT

Invention Title:

Electron beam layer manufacturing

The following statement is a full description of this invention, including the best method of performing it known to us: 2015275236 22 Dec 2015

ELECTRON BEAM LAYER MANUFACTURiNO

CLAIM OF BENEFIT OF FILING DATE foot] The present application claims the benefit of the filing data of U.5. Provisional Application No. 61/243,242, filed September 17, 2000:, the contents of which are hereby expressly incorporated by- reference. FIELD OF THE INVENTION |002| The present invention relates generally to layer manufacturing or fabrication of articles and, more specifically, to additive manufacturing or solid freeform fabrication of articles using electron beam energy and closed loop controi technology,

BACKGROUND OF THE INVENTION IQOZ} Free form fabrication (FFF) and additive manufacturing (AM) are names for a genera! class of layer manufacturing (LM), in which a three-dimensional (3-D) article is made by the sequential build-up of layers of material. Prior to physically building up the article, the process often begins with creating a computer aided design (GAD) file to represent the image or drawing of a desired article. Using a computer, information about this article image file is extracted, such as by identifying information corresponding to individual layers of the article 1 Thus, to derive: data needed to form an article by LM, conceptually the article is sliced into a large number of thin layers with the contours of each layer being defined: by a plurality of line segments or data points connected to form polylines. The layer data rriay be converted to suitable tool path data, such as data that is manipulated by or in the form of computer numerical control (GNG) codes, such as G~codes, M-codes, dr the like. These codes may be utilized to drive a fabrication too! for building an article layer-by-layer.

[004J One or mom suitable LM techniques may be utilized for making articles, (e.g., such as by creating one or more device patterns directly on a substrate). The LM technique usually includes a step of selectively depositing material layer by layer, selectively removing material layer by layer, or a combination thereof. Many LM techniques are attractive in that they avoid the need for masks, for preexisting three-dimensional patterns, and/or expensive tooling.

[00¾ Historically, LM processes that use electron beams for melting a metal have been generally performed in ah open loop fashion, which relies throughout substantially the entirety of the process upon human intervention, and particularly an operator, to adjust operating

1A 2015275236 22 Dec 2015 parameters. For example, an operator typically is obliged to visually observe the LM process throughout the layer by layer buildup, generally external of ah LM apparatus arid through a viewing port of the 'LM apparatus. If and when an operator detects a perceived departure from the buildup process, as forecasted, the operator needs to immediately change operating parameters. This approach may pose potential for complications due to the subjectivity of the observations of: the operator, due to any delay experienced between an observation and any adjustment, in operating parameters, and/or due to improper selection of parameters. £QQ6] fri recent years, there has been a growing need for a reliable system that reduces reliance upon human operators of LM processes and equipment. However, the art has yet to provide an effective solution.

[007] Among the difficulties encountered in attempting to implement closed ioop controls for LM techniques, and especially in the area of LM that employs layer by layer build up of articles using molten metal has been the ability to suitably monitor deposits of metal This is a particularly acute difficuity whan attempting to conduct LM at fsiativeiy high output rates. For example, until the present invention, it has been impractical to use camera-based monitoring systems, especially monitoring systems that control metal deposition using overhead imaging of a metai deposit, Optics may be susceptible to vapor buiid-up that occurs during manufacturing. The amount of data and the rate at which images must be captured for analysis also has faced limitations due to camera hardware. By way of illustration, in achieving rapid imaging, heat may be generated by operation of the associated camera electronics; this may have the effect of corrupting images that are obtained. Overhead positioning of a camera also puts the camera at potential risk of image distortion due to pixel excitation by scattered electrons. Also, suitably robust, commercially practical and compact designs for use, especially in LM, have been unavailable, [OOSj Accordingly, there continues to be a need in the art for ah improved system for monitoring layer manufacturing to provide feedback controls for forming a three-dimensiohal article. More particularly,, a system that provides automatic alteration of processing conditions based on information obtained from monitoring the layer manufacturing of the three-dimensidnai article. |009] Examples of efforts to provide: layer manufacturing of articles and processes include those disclosed in US Patent Nos. 5,534,314: 5,669,433:5,736,073; 5,871,805; 5,960,853; 6.401,001; 6,193,823; 6,405,096; 6,459,951; 6,680,456; 7,073,561; 7,168,935; and 7,326,377; and US Patent-Application Nos. 20030075836; 20050173380: and 20050288813, all of which are incorporated by reference for ail purposes. The possibility of dosed loop controls for 2 1001859776 2015275236 29 Jun2017 additive manufacturing of articles by electron beam fabrication processes is identified at col. 12, lines 8-15 in U.S. Patent No. 7,168,935 (incorporated by reference). In Seufzer and Taminger, "Control of Space-based electron Beam Free Form Fabrication" (accessed at ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20Q700303Q8_2007030399.pdf) (incorporated by reference), the authors address a possible approach to a closed-loop control system. See also, Sharma, “On Electron Beam Additive Manufacturing Process for Titanium Alloys" (Abstract for Session on April 27, 2009 Spring 2009 AIChE National Meeting) (incorporated by reference).

[0010] U.S. Patent No. 6,091,444 (incorporated by reference) elaborates on some of the difficulties faced in imaging high temperature melts. The patent illustrates an example of a high temperature melt view camera that includes a water cooled enclosure with a pinhole in it, through which a gas is passed.

[0010a] Reference to any prior art in the specification is not, and should not be taken as, an acknowledgment, or any form of suggestion, that this prior art forms part of the common general knowledge in Australia or any other jurisdiction or that this prior art could reasonably be expected to be ascertained, understood and regarded as relevant by a person skilled in the art. SUMMARY OF THE INVENTION [0010b] In an aspect, the present invention provides an apparatus for layer manufacturing a three-dimensional work piece, comprising: a) a housing defining a chamber capable of evacuation and within which a metallic work piece is formed layer by layer from a plurality of successively deposited molten pool deposits, the housing enclosing: a. an electron beam gun that melts a metal feed material; b. a table upon which the metallic work piece is formed, the table and the electron beam gun being adjustably spaced relative to each other so that as the metallic work piece is formed layer by layer from the plurality of successively deposited molten pool deposits, the spacing incrementally increases; c. an optical assembly including: i. a first enclosure, ii. optics for reflecting light housed in the first enclosure, iii.an aperture in a wall of the first enclosure for allowing access, into the first enclosure, of light emitted by one or more molten pool deposits so that the light reaches the optics, and iv. a vapor protection device that substantially avoids build-up of metal vapor on the optics during operating of the apparatus; d. an imaging device including: i. a detector array, ii. thermally regulated electronic componentry, and iii. a second enclosure that substantially encloses the detector array and the thermally regulated electronic componentry, and also includes an opening through which light that is emitted by one or more molten pool deposits and is reflected from the optical assembly can 3 1001859776 2015275236 29 Jun2017 communicate with the detector array; and e. a frame that carries the enclosures of the optical assembly and the imaging device in spaced apart relation from each other so that the aperture of first enclosure is substantially overhead of the molten pool deposit, and the first and second enclosures are separated from each other; b)a closed loop control device configured to automatically adjust one or more processing parameters of the apparatus in response to data obtained from the imaging device.

[0011] The present disclosure seeks to improve upon prior LM apparatus and processes by providing a unique process for fabrication of articles utilizing electron beam energy and closed loop controls. The present invention may incorporate any of the teachings described in of U.S. Provisional Application No. 61/243,242, filed September 17, 2009, the contents of which are hereby expressly incorporated by reference. One or more embodiments of the invention may make advantageous use of one or more unique features for allowing rapid article builds, especially aided by dosed loop control operation, such as one or any combination of a vapor protective device as described herein, a cooled camera housing as described herein, an alignment fixture as described herein, substantially overhead imaging of molten pool deposits during a build as described herein, or any combination thereof.

[0012] Disclosed herein is a process for layer manufacturing of a three-dimensional work piece comprising the steps of: feeding metal wire raw material in a solid state to a first predetermined location (e.g., in the form of a bead, such as an elongated bead such as from a wire that may have an average width of about 3 to about 20 mm, preferably about 10 to about 15 mm (e.g., about 12.7 mm)); depositing the metal wire raw material onto a substrate forming a molten pool deposit under a first processing condition by melting the metal wire with an electron beam; monitoring the molten pool deposit for a preselected condition using a detector substantially contemporaneously with the depositing step (e.g. using an optical imaging device, such as a digital camera; comparing information about the preselected condition of the monitored molten pool deposit with a predetermined value for the preselected condition of the monitored molten pool deposit; solidifying the molten pool deposit; automatically altering the first processing condition to a different processing condition based upon information obtained from the comparing step; and repeating the above steps at one or more second locations for building up layer by layer a three-dimensional work piece; wherein the monitoring step (c) includes monitoring a condition associated with the molten pool deposit from a location substantially overhead of the molten pool deposit; wherein the detector is located within a monitoring system 4 1001859776 2015275236 29 Jun2017 that includes a vapor protection device and the monitoring system is located within a chamber that houses the three-dimensional work piece during forming; and wherein the vapor protection device is located so that an axis of a light beam received by the vapor protection device forms an angle from about 0.0,5° to about 20° from an axis of the electron beam. The steps may be performed at a rate sufficient to deposit successive layers at least about 0.5 cm /hr to at least about 2.0 cm3/hr (e.g. about 1.54 cnrVhr), more preferably at least about 2.0 cm3/hr to at least about 5.0 cm3/hr. The steps may be performed at a rate sufficient to deposit successive layers at least about 2.5 kg of the raw material per hour, preferably at least 3 kg per hour (e.g., about 3 .3 to about 6.8 kg per hour or higher). The steps may be performed at a rate sufficient to deposit the raw material as a plurality of beads that define successive layers having an average bead width of about 10 to about 15 mm (e.g., about 12.7 mm) at a rate of at least about 25 cm of bead per minute (e,g., about 35 to 80 cm per minute or higher).

[0013] The above process may in addition to a monitoring step include a step of cooling a detector by flowing a fluid in a housing of the detector for removing heat from the detector, wherein the cooled camera housing comprises: a front flange; at least one spacer pad connected to the front flange; at least one seal adjoining the spacer pad (e.g., located in-between a plurality of spacers, the front flange and spacers, or both); a rear flange connected to the front flange and sandwiching therebetween the at least one spacers and seals; wherein the front flange, the at least one seal, the at least one spacer pad, and the rear flange form an interior cavity, a plurality of printed circuit boards located within the interior cavity; an image detector, and wherein at least one of the flanges (e.g., the front flange) includes an inlet an outlet, a fluid passage between the inlet and the outlet through which the fluid is passed for cooling the printed circuit boards during their operation, and optionally a mount adapter.

[0014] The present disclosure also contemplates an apparatus for LM fabrication of a three-dimensional article comprising: a material delivery device for delivering raw material in a solid State; an electron beam gun energy emission device that emits electrons for melting the raw material to form a molten pool deposit; a work piece support upon which a work piece is formed layer by layer from a plurality of successively deposited molten pool deposits; a detector that monitors a preselected condition of the deposited material; a closed loop electronic control device for controlling operation of one or more components of the apparatus in response to a detected condition by the detector; and a housing defining a chamber within which the work

4A piece is formed layer by layer from a plurality of successively deposited molten pool deposits; wherein the relative positions of two or more of the material delivery device, the energy emission device, the work piece support, or the detector changes during use of the system in at least the x, y, and z orthogonal axes for layer by layer buildup of an article. 2015275236 22 Dec 2015 [0015] The apparatus may have associated with it an alignment fixture that is configured to allow for adjustment of an electron beam gun (and optionally a beam deflector), the detector, or both relative to each other and a known position of a work piece and/or work piece support. The present apparatus affords a robust system for gathering valuable data about a melt pool deposit substantially in real time. By way of illustration, the detectors may be capable of capturing and processing at least about 25, 30, 40, 50, or even 80, or more images per second. The processes herein contemplate operating the detectors at such rates or faster rates. In this manner, substantially real time data may be obtained about the deposited material that takes into account dynamic and unpredictable thermal conditions experienced by the work piece as a result of the layer by layer buildup and ongoing changes to dimensions and geometries of the work piece. The alignment fixture may comprise: a support structure with a base portion and a guide surface portion; an adjustable height work piece support simulator carried on the support structure that raises and lowers relative to the base portion along the guide surface portion; an energy emission device orientation simulator disposed above the work piece support simulator on the support structure, the energy emission device orientation simulator including an interface for alignment of mounting a detection device, an interface for alignment of mounting of a deflection coil, or both.

[0016] The apparatus may have associated with it a vapor protection device that comprises: a block that includes a base portion and a cover portion, the base portion including at least one fluid port that receives a gas stream that may be controllably regulated, the base portion and the cover portion each having an aperture that is generally axially aligned with each other and is adapted to be axially aligned substantially overhead of a molten metal pool deposit; at least one reflective substrate that is in optical communication with at least one of the apertures of the cover portion, or the base portion, for reflecting an image that passes through such aperture to a separately housed optical imaging device that records the image; wherein the gas stream enters the at least one fluid port and exits the block through one of the apertures, and provides an optically transparent protective barrier to prevent passage of metal vapor through the other aperture.

[0017] It should be appreciated that the above referenced aspects and examples are nonlimiting as others exist with the present invention, as shown and described herein. For example, any of the above mentioned aspects or features of the invention may be combined to form other unique configurations, as described herein, demonstrated in the drawings, or otherwise. 5

BRIEF DESCRIPTION OF THE DRAWINGS 2015275236 22 Dec 2015 [0018] FIG: 1A is a general perspective view of an example of hardware useful for a system in accordance with the present teachings and a view of a chamber Of ah apparatus of the present teachings.

[0019] FIG. 18 Is a perspective view Illustrating generally a layer by layer deposition approach:. 10020] FIG. 2 is a perspective view of an illustrative energy emission device and monitor assembly of the present teachings .

[0021] FIG. 3A iiiustrates a side view of an illustrative device for monitoring a molten pool deposit.

[0022] FIG. 38 illustrates an enlarged view of components of a vapor protection device shown in FIG. 3A.

[00.23} FIGS 3C-3D illustrate an example of light beam orientation.

[0024] FIG. 4A illustrates an example of a purge block structure for a vapor protection device. [8025] FIG. 48'Illustrates an example of a component of a vapor protection device herein.

[0020] FIG. S is an example of an image OMainabie using the present teachings, [O027J FIGS, 6A-8B illustrate views of an example of temperature controlled housing.

[0028] FIG. 6Q is an exploded perspective view of a temperature controlled housing.

[0029] FIG 7 is a perspective view of an alignment fixture.

DETAILED DESCRIPTION OF THE INVENTION

[0030] The present invention provides an apparatus and process tor layer manufacturing (LM) of a three-dimensional article. The invention is particularly directed at an apparatus and process for LM that provides high output rates. For example, it is possible that article (eg,, metallic article) build rates of at least about 0.5,1,0,1.5,2,5, 3.5, or even 4.0 errrVhr, or higher, may be employed, it is also possible that, article (e.g., metallic article) build rates of at least about 2.5, 3.0, 3.3, 5, or evert 6.8 kg/hour (e.g. having an average bead width of about 10 to about 15 mm) may be employed.

[0031} In general, the apparatus: may include combinations of at least two or more of a materia! delivery device (e.g. a wire feed device); an energy emission device that applies energy to liquefy a material (e.g,, a metal) delivered by the mote rial delivery device; a work piece support onto which liquefied material is deposited; a closed loop control device [e.g,, one that is in signaling communication with at least one or more of the materia) delivery device, energy emission device, or work piece support); a detector (e.g. a digital camera having (i) electronic 6 components enclosed in a temperature controlled housing; (ii) a vapor protection device; or (Iti) both (i) and (ii)} that detects a condition of materia} that has been deposited (e.g., by employing at least one solid state sensing device for generating an image of the deposited materia! substantially in rea! time) arid supplies information about the condition to the control device so that the control device can change an operating parameter In response to the detected condition; and a housing that at least partially encloses some or all of the above components, in general, the process may include supplying a material (e.g,, a wire feed material); liquefying the materia! (e.g., by applying energy, such as from an electron beam); depositing liquefied material onto a work piece' support as a molten pool deposit; monitoring the molten pool deposit; and controlling operation of die process using a closed loop control system for changing art operating parameter in response to a detected condition of the molten pool deposit. The apparatus and the process may make use of an optical imaging detector that captures and processes data about images substantially in real time, and particularly a camera system that: 2015275236 22 Dec 2015 (i) may be operated at a rat© of at least about .25, 30, 40, 50, or even 60 or more frames per second; (ii) may derive its images substantially Overhead of the melt deposit; (iii) may be operated for extended periods (e.g., at least 8.24, 72, or even 144 hours or longer) without buildup of image distorting vapors on any optical components; (iv) inciudes processing electronics that are maintained at a temperature below about 500, 400, 200, or even 100 G; Or any combination of (0032] As illustrated in FIGS. 1A-1B, the present invention may include a LM apparatus 10 that inciudes a material delivery device 12 for delivering raw material in a solid state (which may include at least one metal, which may be in the form of a wire); an energy emission device 14 (e.g,, an electron beam gun that controllabiy emits an electron beam); a work piece support 18 (e.g., a support that is motor-translated); a detector (e.g. including a camera); an electronic control system with a suitable control device 20 (preferably including at least one microprocessor); and a chamber 22. At feast a portion of one or more ofthe components (e.g,, the control system, a computer* or both) may reside outside of the chamber. The control system may be in controlling communication with one or more ofthe material delivery device 12, energy emission device 14, work piece support 16» or detector. The energy emission device 14 emits energy for melting the raw material to form a molten pool deposit on a work piece support (e.g., onto a previous layer deposited onto a work piece support). The work piece support 15, the energy emission device 14, and/or the material delivery device 12 may be positionally translatable relative to each other, so that a work piece can be formed layer by iayer from a plurality of successively deposited (and solidified) molten poo! deposits. 7 {00333 The detector 18 (FIGS. 2-3B) monitors (e.g., using an optical technique) a preselected condition of the deposited material, for example, bulk average temperature of the molten pool deposit, temperature gradient .-within'the molten pool deposit, surface topography of the molten pool deposit, the presence of any liquid-solid interface in the molten poo! deposit, surface profile (e.g., shape) of the molten pool deposit, chemical analysis of the molten pool deposit, raw material entry location, raw materia! height, raw material orientation, or any combination thereof. The detector may obtain an image from a location substantially overhead of the molten pool deposit so that a material feed wire may be imaged substantially as the wire is melted. The detector may communicate (directly or indirectly via another microprocessor that signally communicates with the control system) information obtained about the preselected condition to the closed loop electronic control device 20. 2015275236 22 Dec 2015 |0G34| The closed loop electronic control system may then signally control (directly or indirectly) operation of one or more components of the apparatus in response to a detected condition. The control device may operate by altering one or more conditions. For example, one or more of the conditions altered may be the location of any energy emission device for supplying, energy to meS the ra w material; the location of any material delivery device used for feeding the raw material; the location of the work piece support upon which a. work piece is Jbuiit; the pressure of any environment In which the processing is performed; the temperature of any environment in which the processing is performed; the voltage or other energy supplied to meit the raw material; the beam used for any electron beam source Of energy for melting the raw material (e.g,, the beam focus, the beam power, beam raster pattern, or otherwise); the feed rate of the raw material; the composition of the deposited material; the temperature of the work piece; the temperature of the platform; or any combination thereof. The detector and control device make it possible to perform an LM process automatically, and especially without the need for operator intervention (e.g., without the need for complete reliance upon subjective human operator observations about operating conditions, without the need for complete reliance upon manual adjustment of one or more operating parameters by a human operator, or both). {0033] Use of the processes and apparatus may require a vacuum, so that a reduction of pressure below atmospheric pressure is achieved. Thus, the apparatus may have its components at least partially enclosed within a wailed structure defining a chamber 22, whieh may be sealed, and within which the work piece may be fanned iayer by layer from a plurality of successively deposited molten poo! deposits. The relative positions of two or more of the material delivery device, the energy emission device, the work piece support, or the detector may change during use of the processes and apparatus herein, 8 [0036] The UlM apparatus 10 includes a material delivery device 12 (FIG. 1A) for delivering raw material in a solid state.: The material delivery device 12 may be structurally connected to a Wat defining the chamber 22 either via direct strus^ural attachment or via an arm 28 (FIG, iA)that permits reorientation of the materiai delivery device 12 with respect to the energy emission device 14, The material delivery device may include one or more:frame structures that carry Individual components, for example, a raw material holder (e.g., an arm that rotatably carries a spool of wire), a wire straightener, a motor, a sensor, or any combination thereof. Optionally, the material delivery device 12 may be adapted so that it is mounted to a portion of the energy emission; device (e,g., a wire feed device may be mounted to an electron beam gun). The material delivery device may attach via direct structural attachment or via a positioning mechanism that permits desired orientation of the materiai delivery device 12 with respect to the energy emission device 14, The raw material positioning device may be configured for orientating the position of the raw material feed relative to the energy emission: device, preferably so that as raw material is advanced (e.g., continuously, intermittently, or both) by the materiai delivery device, and the raw material is delivered into a path of energy emitted by the energy emission device (e.g., wire is fed into the path of an electron beam). The energy emission device, the wire feed, device, or both, may be configured to translate over at least 3 axes of translation {e.g., over the x, y and a axes of a Cartesian coordinate system), and possibly even over 4, 5, or even 6 axes Of translation. Thus, the raw materiai positioning mechanism may orientate the direction of the raw material feed relative to the energy source being emitted from the energy emission device, the moiten pool, the work piece, dr any combination thereof as the volume of the work piece· increases.. 2015275236 22 Dec 2015 [0037] The material delivery device 12 may include a straightening mechanism, at least one feed motor, feed sensors, a raw material supply and/or containment unit, or any combination thereof. Power required to operate the raw materiai feed motors (drive and tensioning) of the materia) delivery device 12 may be supplied from power via the at least one electrical feed-through discussed herein. Examples of welding wire supply and straightening devices are described in U.S. Patent Nos. 4,808,317; 4,020,776; and U.S. Patent Application No. 20080296278, all incorporated by reference for alt purposes, A suitable wire feed device thus may include a motor driven feeding mechanism including a pair of rollers that feeds a wire therebetween. As described in U.S. Patent Application No, 20080206278, incorporated by reference, optionally there may be a tension controller that adjusts a tension between at least one pair of rollers, a wire speed sensor that measures wire feed speed, and a Control circuit that 0 compares a driven speed of the wire with the feed speed of the wire. The tension controller may also adjust the tension between the rollers. 2015275236 22 Dec 2015 {0038] The raw materials used by the LM process may include one or a combination of alloys of metals (e.g., metals including a transition metal or an alloy thereof), Examples of raw materials that may be used are: titanium, aluminum, iron, nickel, chromium, {e.g,, inconel), cobalt;, stainless steel, niobium, tantalum, copper, bronze, brass, beryllium, copper, vanadium, or tungsten. Particular examples of materials useful In the present technology are titanium; and alloys of titanium (e.g,, also including aluminum, vanadium, of both), such as one including titanium in a major amount (or substantially the balance) and about 3-10 wt% Aluminum (ΆΙ) (more preferably about 6 wt%), and 0 to about 8 wt % Vanadium (V) (more preferably about 4 wt%)). The raw material may be supplied and/or fed in various shapes and sizes. In one preferred embodiment, the raw materia! is provided in thefprm of a' wire feed stock. The raw materials may be provided,in an already heat-treated (e.g., tempered) condition, it is also possible that the raw material may be provided in a powder materia! form; in.Which case, the material delivery device will be configured to include a suitable metering device for delivering a predetermined quantity of powder, (0039] The material delivery device 12 may be adjustable so that it is capable of feeding relatively large or even relatively small diameter wires (e,g.t wires supplied by a Wire spool, may have a diameter of about 5 mm or below, about 3 mm or below, or even about 1 mm or below) at both high and low speeds. The material delivery device may include one or more guide structures (e.g. one or more guide tubes 24) that help control wire position. It is also possible that a plurality of wires (of the same or different material type) may be fed from, one or more materia! delivery devices 12, at one or more angles and/or distances from the molten pool deposit.

[0040] The LM apparatus 10 includes an energy emission device 14 that emits energy (e.g., using an electron beam gun or some other source of energy, such as a laser) for mailing the raw material to form a molten pool deposit. The energy emission device 14 may be structurally supported in the chamber 22, as seen in FIG 1A.-1B, via a suitable structurai attachment or positioning mechanism (e.g,, arm 28), which may also carry the material delivery device. The structural attachment or positioning mechanism may be adjustable. For example, it may include one or more attachment features (e.g., fasteners or the iike) that allow it to be secured in a fixed position and loosened or otherwise released for adjustment or re-positioning. The emission device may be configured for orientating the position of the energy beam relative to the work piece and/or work piece support. It may have at least 3,4,5, or even 8 axes of translation (e.g., 10 over at least the x, y.and z axes of a Cartesian coordinate system). For example, the energy emission device 14 may be configured to move an electron beam gun using translation ίπ X, Y, Zj.tift in one or more of theX-Y, X^Z, or V-Z planes, or some other rotation to position the energy beam at a predetermined locator! relative to ipe work piece and/or the vt®H< piece support. [0041J Power required to operate the energy emission device 14 may be supplied from one or more suitable power sources. For example, power may be. supplied via at least one electrical feed-through power supply. The power source may deliver power greater than about 10 kilowatts (kW) or even greater than about 30 kW, The power source may deliver power up to about 100 kW (e.g., up to about 50 kW). The energy emission device may be signally connected to one or mote processor (e.g., a processor of a controller, a computer, or otherwise) for controlling the energy output from the power supply. The processor maybe included in the closed icop electronic control device or may be part of a separate computer and/or controller, which is operated by the closed loop electronic control device. One example of one approach for closed loop control is illustrated in Serial No. 61/319,365. filed March 31,2010, the contents of which are incorporated by reference herein. 2015275236 22 Dec 2015 [0042] A preferred energy emission device may include an electron beam generator that may focus a su pply of electrons against the raw material (e.g,, an electron beam gun). Upon contact with the raw material, the electrons may heat the raw material to cause the raw material to soften, vaporize, and/or meity and thereby introduce the raw material Into a molten deposit, For example, the energy emission device may generate an electron beam (which may be focused to a desired beam width or span). The electron beam may be achieved: with a. low accelerating voltage, preferably between about 3 kV to about 80 kV, more preferably about 10 to 80 kV, and even more preferably between 35 and 55 kV; with a maximum beam power in the range of up to about 10 to about. 15 kW (e.g;, about 3 to about 5 kW); by using about 100 V about 600 V (e.g., 110 V) input power; or any combination thereof. Preferably, the energy emission device may be operated so there is sufficient power density for the electron beam freeform fabrication process, vyhiie stiff providing suitable radiation shielding. The processes herein may operate the energy emission device within some or all of the above parameters, [0043] One approach to the operation of an electron beam gun may be to maintain the parameters of the gun at a sufficient level so that the maximum depth of a molten pool deposit may be about 3 cm or less, more preferably about 1 cm or less, and possibly even about 0.5 cm or less, ills possible that the beam may be operated in a generally defocused mode. For the deposition of a material, the beam: may be rastered in a suitable pattern, such as generally non-ciretiiar pattern (e.g,, ah elliptical pattern, a linear pattern, a: polygonal pattern, or any 11 combination thereof). For example, a beam having a width of about 0.5 to about 0.8 mm may be rastered to cover an effective width of about 1,0,2.0. 3.0 mm, or larger. fn this manner, a relatively large amount of energy may be dispersed over a relatively .large area,: but to a relatively shallow depth, as compared with traditional electron beam welding. 2015275236 22 Dec 2015 [0044) The processes also contemplate operating the energy emission device variably or constantly within some or all of the above parameters. For instance, in response to a detected condition, one or rnore of the above parameters may be varied by a signal sent from a closed loop control device as taught herein. By way of example, the operation of the energy emission device maybe controlled in a suitable manner to achieve a preselected size for a deposited melt pool. The size of the deposited melt pool may be measured by the detector 18 (e.g., metal melt pool deposits are controlled to maintain successively deposited layers so that they exhibit a melt pool diameter or width of about 0.3 mm to about 20 mm of even about 0,5 mm to about 13 mm).

[0045) To the extent not taught expressly herein, or elsewhere herein, other art-disclosed operational parameters may be employed:, such as are disclosed in 11$. Patent No. 7,188,935, incorporated by reference .{see, e.g., cols. 5, 9, and the claims) Other art disclosed energy emission devices may be employed alone or to combination with an electron beam gun, such as a laser.

[0048) The LiVi apparatus 10 may include a work piece support 18 (FIG. 1A) upon which a work piece may be formed layer by layer from a plurality of successively deposited molten pool: deposits (see, s/g,, FIG, I B), and which may provide a suitable conductive path of the electron beam (when on) in order to help avoid static build-up. The work piece support 18 may include a positioning mechanism (e.g., a stopper motor, a servo motor, or some other motor) for moving the work piece support i 8 while optionally allowing the energy emission device 14 Or another component to remain stationary, it is possible that the work piece support 16 may be maintained generally stationary while moving the energy emission device or another component. The work piece support 16 may further include at least one positioning sensor (e.g., rate and location sensors); at least one positioning motor; one or more power lines; or any combination thereof. The work piece support 16 may translate over at least 3 axes of translation (e.g,, over the x, y, and z axes of a Cartesian coordinate system), more preferably tra estates linearly and rotationaily over a total of at least four, five,, or even six axes (e.g,, at least the X, Y, and 2 axes). The work piece support 16 may rotate, clockwise, counterclockwise, or both around any of the axes. The work piece support 18 may be capable of moving entirely or partially outside of the chamber 22, 12 [0047J Layer manufacturing according to the present teachings may orient an energy beam (e,g., an electron beam) vector substantially normal to the surface on which the deposit is being built. This tilt capability (e.g., positioning mechanism) enables positioning of the work piece support at different angles from 0“ (platform normal is parallel to the energy beam vector) to 90? (platform normal is perpendicular to the energy beam vector) to allow enhanced flexibility and capability to build complex geometries, which may include undercuts, overhangs, hollow sections, or any combination thereof. As can be appreciated using traditional manufacturing techniques this has been difficult to fabricate without expensive tooling, coring operations, and/or secondary processing (e.g., machining). 2015275236 22 Dec 2015 [0048] With reference to FIGS, 2-38, the LM apparatus 10 may include one or more monitoring system 30 that rosy include a detector 18, (e.g. an optica! detector or more preferabiy a camera, such as a digital camera), for monitoring a preselected condition. Preferably, for monitoring a preselected condition of deposited materials. More particularly, for monitoring a molten pool of the deposited materials. The .monitoring system 30 or its components (e.g., detector 18) may be located at least partially within the chamber 22. With reference to FIGS, 3A-3S, an embodiment of the monitoring system 30 is shown having a detector 18 with a detector housing 48 (which may he temperature controlled), and an optional vapor protector 32, [0049} The detector 18 may include one or more sensors or other devices (e.g., one that derives its measurements optically, mechanically,;by infrared imagery, by some other radiation detection, or otherwise). The detector may be a solid state device such as one that comprises one or more sensors (e.g., a solid state array effectively including a plurality of sensing pixels) that convert a detected condition into an electrical signal.

[G05OJ The detector may be used so that it monitors a condition associated with a molten pool deposit The detector may monitor bulk a verage temperature of the molten pool, deposit, temperature gradient within the molten pool deposit, surface topography of the molten poo! deposit, the presence of any liquid-solid interface in the molten pool deposit, surface profile of the molten pool deposit, chemical analysis of the molten poo! deposit, or any combination thereof. For example, the detector 18 may be configured to measure the melt-pool energy of the molten pool, which may be determined by measuring the melt-pool size and temperature using an optical technique (e.g,, by use of a. suitable imaging device such as a camera), A preferred detector may employ suitable hardware adapted for machine vision applications, and thus may include one or more housing (e.g., temperature regulated housings). The housing may contain a suitable substrate that includes an array of pixels, and optionally one or more 13 lenses and/or shutters for controlling optical communication between the pixel array and the object being monitored (e.g., a molten pool of a work piece). 2015275236 22 Dec 2015 [0661] The detector 18 may include a camera selected from a high speed video camera* standard video cameras, thermal imaging cameras, stiM imaging cameras, or any combination thereof. The detector i 8 .optionally may include one or more of the'following,ran accelerometer, a thermocouple, a pressure sensor, a current sensor», a voltage sensor, a deflection coil sensor, a focusing coil sensor, a: rate sensor, a location sensor, a wife feed subsystem sensor, ora combination thereof. An exempts of a suitable detector 18 may be a camera (e,g. , a high speed camera) with an image sensor that includes one or more of the following features: an array Of active pixels (e.g;, a complementary metal oxide semiconductor (CMOS) image sensor array, a charge coupled device (CCD) image sensor array, or both); progressive scan; resoiutiorvthat is at least about 640x480;. preferably at least about 752x582; arid more preferably at least about 1024x1024 pixels. Examples of art-disclosed CMOS imaging systems are found in 6,816,685; 7,107,118; and 7,380,697, all of which are incorporated by reference herein. The detector may display results monochromaticaiiy, in color, or both. The detector may fee configured so that it operates at an image acquisition rate or frame rate that ranges from about on the order of at least about 25 frames per second, e.g, , about 30 frame per second (fps) or higher, it may operate at least at about 40 fps, at least at about 50 fps, or evert at about 60 fps, or more. For example, it may operate at about 25 to about 500 fps (e.g,, about 30 to about 60 images per second, about 150 fps, or faster). Suitable sensor arrays for detectors may have a pixel size of about 9x9 pm2 to about 12 x12 pm- (e.g., about 10,6 x 10.6 pm4).

[0052} Suitable cameras mayincludea CMOS active pixel image sensor, CCD image sensor, or both, preferably housed together with suitable optics and associated electronics. Examples of preferred cameras are available from Photon Focus of Switzerland (e.g., sold under model number MV-D1024E-40-CL-12, MV-D752-28-CL-10, or MV-D1024E-16O). An example of a preferred camera may include a dynamic range with a relatively high contrast resolution (e.g. at least about 80 d8,120 d8,140dB, or more), and a shutter and/or an electronic shutter (e.g. a shutter that controls exposure time electronically (i.e.t allows the camera to coiled Sight for a finite amount of time) without any mechanical or moving parts) that may be: used for high speed applications with an exposure time of about 5 to about 1000 ps (e..g„ about 10 ps), A camera may employ a suitable imaging array as is employed conventionally for monitoring Welding conditions. The camera may have a skimming feature. The imaging sensor may operate over a spectral range of about 200 to: about 120.0 nm (e.g. about 350 -1000 nm). 14 [0053] With reference to FIG, 3D, one possible approach may be to employ a monitoring system that includes a detector with intermediate optics that allow images to be captured substantially overhead of the melt pool deposits. For example, the detector may face a reflective substrate 34 {e.g., a mirror or other suitable member that reflects: ah image) that may be positioned between the detector and the object to be imaged :(e.g. a weld pool}*. The reflective substrate may be positioned so that the detector has a line of focus (A) (e.g. a path from the detector to the reflective substrate) that may be approaching generally perpendicular to the electron beam, and toe reflective substrate may have a line of focus <B) (e.g., from a pinhole of a purge block to the imaged structure) that is positioned generally in alignment with the path of the electron beam. 2015275236 22 Dec 2015 [0654] FIGS. 3C-3D, provide one specific, but not limiting, example of the light beam orientation relative to the energy beam. The energy beam being directed from the energy emission device 14 extends along axis (C), which may be generally perpendicular (e.g., about 00°) relative to the work piece support 16. The positioning mechanism of the monitoring: system 30 may position the vapor protection device 32 so that toe tight beam may be received by the vapor protection device extends along axis (A), which may be at an angle (a) of from about 0.0513 to about 20° (e.g., about 2d to about 10s and more preferably about 6“) from axis (C) (FIG, 3C). Thus, the angle (o) may be about 20° or less or even about 10° or less, In one preferred embodiment, the light beam generally deflects at about a 90° angle tom being received by the reflective substrate 34 to being deflected to the detector 18 (FIG, 48).

[0055] The detector may be used in any step of monitoring, which may include capturing an electronically stored image substantially in real time (e.g„ it is less than 5, 4, 3, 2,1 or, lower, seconds from the time of the event recorded). The sensing device may detect electromagnetic radiation emitted from interaction of the electron beam with a material in the work piece (it being recognized that the work piece will include any present molten deposit) to be imaged, [0066] Detection according to toe present teachings may be for purposes of directly obtaining a measurement that is indicative Of a condition of a pool deposit I t is possible that a defection technique may be em ployed that indirectly measures a condition of a pool deposit by observing a detectable characteristic, .and then correlating the detected characteristic with an indication of a particular condition. To illustrate, under this approach, oscillation frequency of a pool deposit may be monitored, and may be correlated with a depth of a deposition pool, it being theorized that a higher detected frequency may indicate less penetration of a molten pool deposit into a previous deposition layer. FIG. 5 is an example ofa molten pool image that may be achieved using the detector. The wire feed in these,images is entering from the left side. As is seen, 15 overall the shape is generally round and generally axially symmetrical- 'It .includes a generally C-shaped portion (Q) with a generally circular or elliptical shaped portion (X) (which may correspond to an image of the feed material) that is within the G^shaped portion, and possibly extending outside the opening Of the O-shaped portion. The process herein contemplates that adjustments may be automatically made to the system so that a predetermined shape for the image is obtained, a generally axial symmetry is achieved, or both, 2015275236 22 Dec 2015 [00.57} The LM apparatus 10 may include a housing that defines a chamber 22 wherein the work piece may be formed. The housing preferably may form a Sealed chamber capable of maintaining an evacuated environment The major components of the LM apparatus 10 may be contained within the sealed housing (e,g.t the,materia! delivery device 12, the energy emission device 14, the work piece support 16, and the detector 18).

[0058] in one embodiment, the housing may include a frame and at. least one wall formed of a material. The wall may be made of ceramic, a ceramic composite, a metal matrix composite, a polymer matrix composite, or a combination thereof. In another embodiment, the frame and at least one wail may be made of titanium, aluminum, aluminum alloys, beryllium alloys, stainless steel, steef or a. combination thereof, which may provide for radiation protection and structural integrity. The housing may further include at least one window for operator visibility as well as monitoring by cameras or a video system. If should be recognized that, even though the present invention obviates human operator intervention, the processes and apparatus here may be. practiced with some human operator intervention; however, any such intervention may be considerably less than prior systems, and may be aided by real time data acquisition from the monitoring system.

[0059] The at least one window may be formed of a transparent material such as leaded glass, glass, transparent plastic, or any combination thereof. The housing may include at least one door attached to the frame or wall to allow full access to the chamber's interior, when not under vacuum. The sealed housing includes at least one electrical and/ or data cord feed-through (not shown) for connecting the material delivery device 12; the energy emission device 14; the monitoring system 30 (e.g., detector 18); motors for positioning mechanisms (e.g„ for the material delivery device, energy emission device, monitoring system 30, the work piece, support, or otherwise); or any combination thereof, with a power source and/or instrumentation (e.g. computer system) located outside the housing.

[0060] As seen in FIG. 1A, the housing may be a generally larger rectilinear cross-sectional shape. However, other shapes and sizes are possible, in one embodiment, the sealed chamber may be generally small so that the housing may ba portable. As discussed above, the 18 housing provides a seated chamber that, may be evacuated using a vacuum mechanism {not shown} to reduce the pressure of the chamber below atmospheric pressure. For example, a pump, blower, some other fluid mover, or a combination thereof may be used to reduce the pressure within the chamber. The pressure within the chamber may range from about IxlO4 to about 1x1torn (or possibly lower). Furthermore., the pressure within the chamber may be less than about 0.1 'to.fr, preferably less than about 1x1 O'2 torn and mom preferably less than about 1x1 O'4 torr. 2015275236 22 Dec 2015 [0061] The effectiveness of the above described detectors and monitoring steps may be. dependent upori assuring a clear line; of sight between the sensing elements of the detector and the object being measured (or any intermediate optical elements, such as mirrors {e.g,, one or more mirrors that may be used for beam modulation)}. However, the process and/or apparatus may generate raw materia! vapor that may be susceptible to deposition onto hardware associated with the detector. For example, vapor may deposit upon a lens of the system, ahd/or upon another optical element (e«g. a mirror), Accordingly, with reference to FIGS. 3A and 38, the apparatus may include a suitable vapor protection device 32, which functions to Impose s protective barrier {e.g;, a solid barrier, a fluid barrier, or both) forward of one or more of the vulnerable exposed components. Preferably, the vapor protection device 32 will be such that if resists vapor disposition build-up onto the exposed componentry so that the vapor does not build up and adversely affect measurement, integrity. The vapor protector device may include one or any combination of a relatively low surface energy coating (which may be substantially transparent to toe radiation being detected) that delays vapor deposition build-up onto a surface as compared with a surface without the Coating; a solid physical barrier {e.g,, a shutter, a curtain, or other barrier that can be opened and closed toexposethe componentry as desired); a fluidic barrier (e.g., a gas stream that can be controliably flowed to expose toe componentry as desired); or a combination thereof.

[0062] A vapor protector device may be located Substantially adjacent to a barrier with an aperture that may have an optical element located behind the wall (e.g.., a beam modulation aperture). A vapor protection device. 32 may be positioned substantially adjacent with the detector 18 (e.g,, proximate to the lens of a camera}, remote from.the detector 18 (e.g., proximate to a reflective substrate 34 as in FIG. 38, but laterally spaced apart from it), or both.

In a preferred embodiment, as shown in FIGS, 3A-38, the barrier with an aperture 42 may be located juxtaposed the second opening 38 of the housing 44, The protective device 32 may indude a protective means, for reducing or eliminating vapor buildup, such as a purge system: The purge system may include a purge line (not shown) attached to a fitting 46, and a port so 17 that the fitting and. purge line may be connected to the vapor protection device for delivering a fluid into the housing 44,. The fitting 46 may be a compression fitting and may attach to a tube or a pipe, As discussed herein, the fitting 46 may be positioned proximate to the barrier with an aperture 42 so that a fluid stream may enter through an intake port 84a and may be directed towards (e.g., laterally) the opening of the barrier 42 in the direction (E) (as indicated ifi Fig. 38). The gas stream may exitthrough an exhaust port 64b, 2015275236 22 Dec 2015 (0063] The vapor protector device 32 may be operated in an intermittent manner, allowing periodicdirect line-of-sight exposure (via One or more pin-hole aperture 102. of the detector to the Object being sensed. The fluid may be generally optically transparent, thereby allowing an image to be received through the. aperture. For example, periodic bursts of a fluid (e.g., a substantially inert gas such as helium) may be biown to effectively blanket the pinhole aperture 102. in this manner, it may be possible to clear vapor away from exposed componentry. The vapor protector device 32, preferably, may be operated in a continuous manner. For example* one or more pumps (i.e. a vacuum pump) maybe used to create a periodic and/or continuous flow of the fluid that exits through the pinhole aperture 102, and may generate a positive pressure inside of the vapor protector device 32. The one or more pumps may be operated so that the pumps are not overwhelmed while still maintaining the flow of the fluid at a constant rate and pressure such that the yapor particles are prevented from building up on the internal surfaces 6f the vapor protector device. The; pumps may be controlled by the. dosed loop control system that operates the various components herein or independent of such system., (0064] The monitoring system may include a barrier with an aperture 42 :(*.§., what is regarded herein as a pin-hole aperture 102). For example, the pin-hole aperture may be an aperture having a diameter qr width (mg,. circular, ovai, slit, or otherwise) of.about 0,50 mm Or greater, of about 2,0 mm or greater, of about 3.0 mm or greater, or even about 5.0 mm or greater) and any associated optics. Other components of the vapor protection device may also include a pin-hole aperture, which may be axially aligned with the pin-hole aperture of the barrier 42 along axis (8). The barrier with an aperture 42 may be, for examples an optical aperture, a standard aperture, or both for controlling the diameter of a beam from a light source (e.g., for modulating the beam by limiting the tight admitted therethrough), producing, optimal diffraction patterns, or both, preferably during the course of detecting by the detector 16. Forexample, a barrier with an aperture of a various size (e,g„ adjustable) or a constant size, where size (e.g., diameter) may be determined from the equation: D2 - (KAab) / (a + b); where: D ~ Diameter of the opening (e.g., pin hole) (e.g., about 0:076 mm) 18 Κ - Constant between 1 and 4 (e.g., about 3.24) 2015275236 22 Dec 2015 A ~ Wavelength of the light (e.g., about 660nm) a = Distance from the subject (e.g., wbribpiece such as the molten pobi deposit) to:the opening (e.g,; about 330 mm) b - Distance from the opening to the image plan© (e.g., deflector such as the mirror) (e.g., about 12.7 mm) jOOSSJ With reference to FIG, 3A - 3B, the vapor protection device 32 may include a block that includes a base portion 60 and cover portion 62 {particularly a pin hole retainer member (such as illustrated in RG. 48)) that may be attached to an outer surface of the base portion. The base portion may include at least one port 64 (e,g.<; penetrating from a side wall,, of for receiving a gas stream that may be controllabiy regulated). The port 64 may be in communication with a passage 66 which may be configured for receiving the barrier member with an aperture: 42. The passage may be recessed so that the barrier member with the aperture 42 may be generally maintained in place once the cover portion 62 is secured to the base portion (e.g., the barrier member Is fixed between the cover and the base portions, as can be seen in FIG, 3B), The passage 6.6 may include an opening (e.g., bote) so that gas received by the .port 64 may be directed through the passage, and may contact the barrier with an aperture 42 and more specifically the pin hole aperture 102. Optionally, as can be seen in Figs. 4A-4B the cover portion, the base portion, or both may include one or more shoulder 68 upon which the)barrier with an aperture may be rested, and the cover 82 may be attached onto a surface 60a. The cover and barrier with an aperture may be heid in place by a pin-hole retainer 108. The pin-hole retainer 106 may include one or more retaining ring 112. The vapor protection device 32 may be further configured as a mounting structure for the barrier with an aperture 42 relative to the other components of the apparatus. The base portion 60 may be designed to provide a complementary fit with the barrier with an aperture 42. The base portion 80 may act as a protective structure directing the exhausted gas from the port 64 to adjacent components (e.g., mirror, windovvs, camera lens, or otherwise). (0068) One or more suitable conduits may be employed for supplying the fluid. The one or more suitable conduits may be housed separate or independent from the components of the detector. For example, the one or more suitable conduits may be independent of (e,g., not attached directly) the detector housing (e.g., a camera housing). Rather, the vapor protection device and the housing {though possibly carried by a common structure) may not be commonly enclosed with each other. Thus, the vapor protection device may be longitudinally separated 19 from the detector housing (e.g., camera housing), and one or more suitable conduits may be connected directly to the vapor protection device hut not the housing- [0067] As discussed, the monitoring system may indude a suitable structure that allows the sensing device of the detector to be oriented away from the direct fine of sight with m object being monitored, but which still captures an image substantially overhead of the melt pool deposit in this case, it may be possible to employ a reflective substrate 34 such as a mirror (e.g., flat, concave, or convex), more particularly a silver mirror available from Edmund Optics. The reflective substrate 34 may be configured to deflect light according to an indirect path from the work piece (e.g., molten pool or otherwise) to the detector. The vapor protection device 32 may further inciude a reflective substrate adjustment knob SO (e.g. a threaded device that connects adjoining pieces and is translatable to adjust/position the adjoining pieces relative to each other) so that the reflective substrate may be kept in the direct line of sight with the object being monitored. The reflective substrate is substantially resistant to image distortion when subjected to operating conditions of the system. For example, the reflective substrate may exhibit a relatively low thermal expansion, e.g., within about +/-0,10 x 1Q'6 per °C. 2015275236 22 Dec 2015 {0063j The reflective substrate 34 may be mounted in a housing 44. The housing may create a line of sight to the reflective substrate. The fine of sight may be an angie (p) (See FIG. 38) between about 0 and about 180 degrees, more particularly between about 30 and about 150 degrees, and even more particularly between about 60 and about 120 degrees (e.g., about SO degrees), [(50893 The housing 44 (e.g., a 16 mm, right angle, kinematic mount) rhay be a generally sealed unit so that contamination and/or vapor deposition buildup may be substantially reduced or eliminated, in one embodiment, the reflective substrate 34 may be generally sealed within a housing 44.having at least two openings with a first opening 30 for receiving the beam of light from a predetermined location (e.g., the work piece, the work piece support, or otherwise) and a second opening 33 for reflecting the beam of light to the detector 18. The first opening 36 and second opening 38 may inciude a generally transparent substrate 40 or otherwise for allowing the light beam to be directed through the housing 44 while generally maintaining a sealed environment. More particularly, the generally transparent substrate 40 may be a glass window (e,g, a glass window or a borofloat glass optical window) or a Jens (e.g. an Esea Doublet #A912150). The transparent substrate may be a com pooent Of the detector or may be separate therefrom. The transparent substrate may be held in place by one dr more retaining ring. 30. in one preferred embodiment, the transparent substrate 40 may inciude a resistant material (e.g., coating) that substantially prevents or eliminates vapor disposition buildup. The resistant 20 material may exhibit one or more of the following characteristics; a low coefficient of expansion, visibility to near infrared transmissions, a high resistance to thermal shock, chemical resistance, an anti-reflection., or any combination thereof. The resistant material may include borosilieate, |007GJ As will be described in further detail, the detector 18 or any of its sensing devices may be partially or completely encased in a detector housing 48, which may be ihennaliy regulated so that the temperature of the detector or its components may be controlled (e.g.. for cooling its electronic components). As seen in FIGS. 2 and 3A, there may be a suitable support member 1Q8 (e,g., a flange) for supporting the housing 48 relative to the support, base 82. The monitoring system 30 may be attached to the housing of the energy emission device using an attachment structure 110 (e.g., a flange). For example, as depicted there is a support base 82 from which a mount wail 84 projects awayfe.g., upward). The support base 82 and the mount wali 84 may be. substantlaily perpendicular to each other. At one end of the attachment structure,; such as at an end 86 of the support wali there may be a mechanism 88 (e.g., a fastener) for removable attachment. Attached to the mounting wall 84 may be one or more rotational mounts 90, The support base 82 may include one or more adjustment mechanism 114 that allow axial translation. For example, the support base may include two opposing members that are slidable relative to each other, but provide opposing support surfaces. An example may include a dovetail adjustment structure as seen in FIG. 3A. The support, base 82 may be attached to a common carrier with the energy emission device:. The monitoring system 30 may be secured to the energy emission device 14 so that at least a portion of the monitoring system 30 (e.g., the vapor protection device 32) may be positioned within the housing of the energy emission device, or at least substantially adjacent to the part of any emitted beam. 2015275236 22 Dec 2015 [0071] The monitoring system 30 may further include one or more ions tubes 52 extending between the detector18 and the vapor detection device 32, as Illustrated in FIG, 3A. A lens tube 52 may be configured to isolate the light beam associated with an image from the surroundings. The lens tubes may include one or more transparent substrates 40 (e.g., a Sens) that may be held in the ions tube using one or more retaining rings SO. The tens tube may be spaced apart from and is not housed with the reflective substrate of the vapor protection device, as illustrated in F|G. 3A, [0072J The monitoring system 30 riiay further include one or more support members 54 and 54’ (e,g., elongated members such as rail carriers, a cage system, dr a ctege structure (as Illustrated In FIGS, 3A-3B)) to provide connecting support for the detector 18, the lens tube 52, the vapor protection device 32, or any combination thereof. It is possible that the cage system created by the one or more support members 54 will have no overlying housing. Thus, the vapor protective 21 device and the camera may be separated by an open cage structure. A plurality of elongated support members 54 and 54’ may be telescopically connected to each Other for allowing lateral translation and adjustment. The support members 54 may be configured so that they allow the detector 18 to receive an image from: the reflective substrate 34 white protecting the monitoring system 30. The support members 54 may allow for a generally linear path through the lens tube 52 to the refiective substrate 34, The monitoring system may include an adjustment mechanism 56 (e.g, an axially translatable mechanism) to adjust the position of components of the optical system (e.g., the vapor protection device 32 (e.g., linearly towards or away from the detector 18)). The support members 54 may further be configured, to provide axial adjustments. In this manner, a fluid line may be maintained separately from the detector (and particularly a temperature controlled housing) and can be manipulated without disturbing the detector. 2015275236 22 Dec 2015

Though the vapor protection device and the cooled camera housing may be carried on a common support structure, the vapor protection device may be decoupled from the cooled camera housing. £0073] Optionally, it is appreciated that the LM apparatus 10 may further include one or more cooling mechanisms such as a heat sink to absorb and dissipate heat in regions Where heat build-up is expected. For example, the detector 18 may further include a water cooled housing (e.g., within the camera housing) with a direct chip level heat sink to generally maintain the detector wifiln normal operating conditions, £0074) in genera!, such a cooled camera housing, may include a housing that surrounds electronic components (e.g., at least one printed circuit board) associated With the detector (e.g., electronic, components of a camera). The housing preferably includes a passage defined in at least one wail through which a heat exchange medium (e.g;, a suitable liquid coolant) is flowed. Desirably, the heat exchange medium is passed through a waii at a location between any beam from the energy emission device (e.g., an electron beam from an electron beam gun) and the electronic components), By way of example, the cooled housing may include a plurality of stacked flanges, at least one of which has a passage at least partially laterally defined therein through which the heat exchange medium is flowed. As illustrated, some er ail of the flanges may define a generally ring shaped peripheral portion that surrounds at least one through hole that defines a cavity. The flanges may be configured to include one or more support surfaces, brackets, or Other structures to which a component (e.g,, an electronic component) may be mounted or otherwise supported. The flanges may. adjoin each other arid be separated by a relatively resilient but thermally conductive layer, and particularly a polymeric (e.g., acrylic based) spacer pad. 22 [007SJ An example of a cooled housing may include a plurality of flanges, and more preferably: at least three axially aligned flanges: that may be separated by spacers. At least one cavity may be defined within the assembled flanges, within which efieast one electronic component is housed, such as one or mere printed circuit boards. An image detector (such as an array of pixel sensors may also be contained therein, and be in at least temporary visual communication with an object to be imaged. At least one flange (e.g,, a front flange) may include an inlet and an outlet so that a fluid may be circulated through the front flange (e.g. , at least across the length or width of the flange). The front flange may further include a mount adapter (which may be located in a central region of the front flange.} that enables mounting of the associated hardware to the housing. The flanges may he assembled together and connected such as by way of a plurality of suitable fasteners. Two or more of the Internal components may be connected to each other in signaling communication. The rear flange may include suitable structure configured to afford connection of powered components with a suitable energy source, or through which cables or other signal lines may be passed. The housing may have a generally rectangular cross sectional outer profile along the longitudinal direction of the housing, other shapes are also possible. The housing may be longitudinally spaced apart from the vapor protection device described herein, and may not share a common enclosure with the vapor protection device. Thus, any pinhole aperture for resisting vapor buildup and associated with mirror or other reflective optics may be housed in a separate enclosure. The housing may be free of any line or other conduit for supplying a gas to the vapor protection device; thus, the housing may be free of any fluid (e.g,, gas j that passes through it for resisting vapor build-up, [0076] FIGS, 6A-SC illustrates an example of a cooled housing 200 that includes a front flange 200 (shown with e lens opening and an adapter) having a plurality of spacers 210 connected to the front flange 200. A plurality of seals 214 (e.g. polymeric Interface seals) may be located in-between the spacers, in-between the front flange and a spacer, in-between the rear flange and a spacer, or any combination thereof. A rear flange 230 may be connected to the plurality of spacers and/or seals and located toward a remote end of the camera housing. The front flange, seals, spacer, and back flange form at least one cavity 260 into which at least one electronic component may be contained (e.g., a plurality of prmted circuit boards 220 may be located within the cavity). The printed circuit boards may include at least one interface pad 222, an energy source 240, an image detector 250 (such as an array of pixel sensors located forward of the pad 222). One or more flanges (e.g. the front flange 200) may include an inlet 202 and an outlet 204 so that a fluid may be circulated through the front flange (e.g,, at least across the length qr width of the flange). For example, the inlet and the outlet are illustratively depicted as 2015275236 22 Dec 2015 23 including a substantially perpendicular elbow joint fitting. The front flange may further indude a suitable mount adapter 206 (e.g., a G~mourit adapter, S-mount adapter, F-mount adapter, or the like (which may be located in a central region of the front flange}} that enables mounting of the associated hardware (not shown) (e.g,, a camera tens) to the housing (i.e., front flange). The mount adapter may be secured in or to the front flange using a plurality of pins 208. For instance, one or more pins or other members may penetrate the side waits of the front flange so that the pins or other members can be brought into contact with the mount adapter 206 to resist the adapter from being putted out. The flanges may be assembled together and connected such as by way Of a plurality of suitable fasteners. For example, some or all of the front flange, seais, spacers, and backfiange may be connected together by a fastening device 284. The fastening device may be a bolt, screw, pin, rivet, or the like. Ope or more of the printed circuit boards may be attached to the spacers or seals by a suitable connection device 224 (e.g, a fastener). The rear flange 230 may indude one or more connection ports 232 that are configured to connect with a suitable energy source 240, or through which cables dr other signal lines may be passed, The front flange 200, spacers 210, rear flange 230, or a combination thereof may indude a vent hole 270 (e.g. through a side wail). The housing may be vented by applying a negative pressure to the vent hole 270, the housing may be vented by applying a positive pressure to the vent hofe 270, or the housing may be vented without any forced ventilation. 2015275236 22 Dec 2015 (0077] As indicated, the flanges or the spacers may be configured to include one or more surfaces, brackets, or other support structures 212 to which a component (e.g., an electronic component) may be mounted or otherwise supported. For example, a support structure 212 may be configured with a recess, well, window, or other opening into which a component may be inserted (e.g., so that it achieves a friction fit, an interference fit, or both) so that at least a portion Of the component is surrounded by the support structure when, assembled. The support structure may be cantilevered relative to the surrounding wall, itmay have openings therein, it may Include a fiat surface, or -any combination thereof, The spacers and/or seais may further be configured to include one Or more heat sinks (216). (0078) The front flange, spacers, seals, and rear flange are generally rectangular In their peripheral shape, though other shapes may be used. Thus, they may have an aspect ratio that is the ratio of the width (W) to the length (L) of the rectangular periphery. For example, the housing may have an aspect ratio of about 2 to 1, preferably about 1.5 to 1, and more preferably about 1.2 to 1. intermediate flanges may be generally rectangular rings. 24 [0G?9J The front flange, rear flange, and spacers maybe made of an insulating material or a material that conducts heat (i.e, aluminum). The materials desirably will resist degradation throughout the temperature range to which they are exposed, The front flange, rear flange, or Spacers may contain an inlet, outiet. Or both. The inlet and outlet may be located on opposite sides of the front flange facing each other (FIGS, 6A-6C). They may be provided with suitable fittings for attachment to tubing for circulating a heat exchange medium. Of course, the image detector may include a charge coupled device (CCD) for sensing, a complementary metal oxide semiconductor sensor (CMOS), or some other active pixel sensor. One approach contemplates the selection of materials and configuration for the seals so that the seals function to conduct heat rather than insulate. For example, one or more;of the seals may be made of ceramic, glass, acrylic, fiberglass, silicone, metal, or the like. 2015275236 22 Dec 2015 [0080| Either or both of the seals 214 of the interface pads 222 may be thermally conductive and generally resilient. For example, they may be polymeric. The at least one interface pad 222 may function as an interface pad, particularly a thermally conductive interface pad, and more particularly a thermally conductive polymeric interface pad. Some properties that the at least one interface, pad 222 may exhibit include having: good softness, conformability to non-flat surfaces, excellent compressive stress relation, high thermal conductivity, good surface tack that leads to a jaw thermal resistance at its surface, good dielectric performance, and excellent durability for both long term thermal conductivity and electric insulation stability. The at least one interface pad 222 may be a non-silicone acrylic elastomer, arid may be flame resistant (e.g„ it meets requirements for certification under UL94). For example, the at ieastone interface pad 222 may include a flammability of about V-0, measured using the UL94 flammability test method.

[00811 One or more printed circuit, boards may be disposed on a support 212, With an interface pad 222 between them (e^g, the interface pad is compressed between trie circuit board and foe support). The interface pads 222 maybe interferingly fit into a complementary receptacle in the support structure 212 of one of the flanges. Thus, it is possible to achieve a thermal conduction pad (e.g. a continuous thermal conductive path) within the housing between the electronics and the housing. The interface pads: 222 may effectively fill air gaps between the electronic components: and their support structures in the housing so that a thermal conduction path of a relatively large area is realized. The interface pads may have a surface that contacts: the opposing electronic component over at least 30%, 50%, 75%, of more of"the outer opposing face of the component, thus, spreading the area for heat transfer, it is thus possible to see how a Compact geometry camera housing can be achieved by which heat transfer primarily by 25 conduction (with or without convective assistance, e.g., a circulated fluid) is reaped by the teachings herein, for cooling the internally housed electronic components. Meanwhile convective cooling may be used for cooling the housing that becomes heated by the conducted heat of the housed components, The teachings herein, thus, also contemplate steps of cooling internally housed electronic components by a thermal conduction arrangement (e.g, an arrangement that consists essentially of codling by thermal conduction) to transfer heat te a housing body, and remove heat from the housing; body using a fluid. 2015275236 22 Dec 2015 10082} The at least one interface pad, the seals, or both may have a density (g/cm'\ @25°C) of about 0.5 or more, more preferably about 1.0 or more, and still more preferably about 1.5 or more. The density may be about 5,0 or less, more preferably about 3.5 or less, and still more preferably about 2.5 Or less (i.e. from about 1.9 to about 2.1), measured using the JiS K6249 test method. The at least one interface pad 222 may have a hardness of about 5 or more, more preferably about 10 or more, arid stiil more preferably about 15 or more. The hardness may be about 100 or less, more preferably about 60 or less, and still more preferably about 35 or less (i.e. from about 16 to 30), measured using the Asker G test method. The at least one interface pad 222 may include a volume resistivity (ς-cmj of about 1.0 X10i2 or more, more preferably about 1.5 X 101S or more, still more preferably about 2,0 X 1Q,S or mere. The volume resistivity may be about 6,0 X 1012 or less, more preferably about 4.5 X 10'2 or less, still more preferably about. 3.5.0 X TO12 or less (i.e. from about 2,7 X 1012 to 3,4 X 10rs), measured using JIS K6249 test method. The at least one interface pad 222 may have a dielectric strength (kV/mm) of about 10 or more, even about 15 or more, and even about 20 or more, Thedieiectrie strength may be about 75 or less, about 50 or less, or about 35 or less (i.e;. from about 21 to 33), when measured using JIS K6249 test method. The thermal conductivity may be at least 1 (W/MWK) (e.g, about 2, 3, 4, or even higher), measured using ASTiM E1225-04, The thickness of the material may range from about 0,5 to about 1,5 mm. Smaller or larger thicknesses are possible |O083J The at least one interface pad 222, the seals 214, or both may include one or a plurality of layers, For example,, it may include a surface layer and a core layer. It may also include a liner (e.g., a film liner). The layers may be polymeric. They may differ in terms of rigidity. For example, the surface layer may be more rigid than that core layer, or vice versa. They may differ chemically. They may be a thermally conductive elastomeric material. They may he an acrylic material. An example of a material that may be used for the at least one interface pad is Thermally Conductive Acrylic Interface Pad, available from 3M under the designations 5589H and 559QH. 26 [0084] When:the housing is assembled together it wifi have a height (H) that spans from a forward face of the forward Range to a rearward surface of the rearward fiange, The ratio of the height (H) to the width [W) and to the length (L) may range from about 1:2:2 to about 1:1.:1 fi.e. about 1.: 1.2:1,3), Preferably, the tent flange 200 wiii have the largest height when compared with the spacers and the rear flange. The ratio of the height of the front fiange (F) to the overaii height (H) of the housing when assembled together may range from about 1 to 1,5 to about 1 to 4 (i.e., about 1 to 2,5), 2015275236 22 Dec 2015 [0085] As discussed the image detector 250 may be any type of device for imaging the inside of a chamber p.e. infrared video camera, television camera, CCD, or the like). As discussed, one preferred detector uses a CMOS array, it is further contemplated that the housing may be free of air circulation. However, air may be circulated through the housing, the circulated air may be conditioned, or the circulated air may be. an inert gas. The camera may be placed in the housing so that the camera is cooled; preferably the housing may be a part of the camera so that the housing protects and cools the components.

[0086] The teachings herein also contemplate the possible use of a Faraday cup or other metal cup that catches charged particles in an evacuated condition, and computer tomography software that analyzes power distribution therefrom. An example of such a device employs technology from Lawrence Livermore National Laboratory and is available from Sciaky, Inc.,· under the designation ESSAM 20/20 Profiler,. A grounded heat sink may include a Faraday cup or the like, in'art insulated chamber. The heat sink may have an opening in its top that has a tungsten siit disk With radial silts (e.g.„ about 17 slits) disposed above a copper slit disk with radial slits (e,g„ about 17 slits), A graphite slit stop may be within thecup, above a copper beam trap and a graphite beam stop. Such device may be employed in a method that includes steps of (1) quantifying power density distribution, (2) determining the sharpness of focus of an electron beam, and/or (3) correlating machine settings, with beam properties.

[0087] The LM apparatus 10 further may include a dosed loop electronic contra! device 300 (FiG, 1 A) for controlling operation of one or more components of the LM apparatus 10 in response to a condition detected by the detector 18. in one embodiment, one or more of the controls (e.g.* dosed loop control device 300) and data acquisition may be electronically managed through a user interface and display device (e,g„ suitable instrumentation, such as one or more computers). The closed loop electronic eontroi device may operate to: perform one or any combination of functions. Most generally, the closed loop electronic control device may acquire one or more signals obtained by the detector 15 (e.g., in real time, as the detector or any sensing device is monitoring the work piece). The dosed loop electronic control device 21 may process the signal by comparing it with a stored value (e.g:,, a value that is programmed into a database, a value from a previous reading, or both). Based upon the step of comparing, the closed loop electronic control device may issue a command that may cause the processing parameters to be changed to one or more different processing parameters (e.g., the dosed loop electronic control includes a processor that is programmed to perform the comparisori and then issue a certain signal based upon the resuits of the'comparison), For examples»·· the closed loop electronic control device may issue signals to one or more of the following; the material delivery device, the energy emission device, the work piece support, the detector, an electrical supply, a vacuum device, a gas supply, or the vapor protector. The command from the closed loop electronic control device may cause the alteration of one crmore oohditiohs, as have been described previously. The conditions that may be altered may be one or more of the following; the location of any device for supplying energy to melt the raw material; the location of any device used for feeding the raw material; the location of any platform upon Which a Work piece is built; the pressure of any environmentin which the processing is performed; the temperature of any environment in which the processing is performed; the voltage supplied to melt the raw material; the beam used tor any electron beam source of energy for melting the raw material; the feed rate of the raw material, the composition of the deposited material; changing the temperature of the work piece; the temperature of the platform; or any combination thereof. Examples Of suitable software that may be used for the programming of devices used in the present invention include software available from National Instrumentsf Austin, TX) under the designation Ni Developer Suite (including LabViEW PDS, LabWindows/CVt, Measurement Studio, SignalExpress, LabViEW and LabWindows, and optionally image Acguisition) and Machine Vision Option for Ni DevSuite (includes Vision Development Module, Vision Builder for Automated Inspection, and Vision Builder for Ai Development Kit). 2015275236 22 Dec 2015 [0088] The control device: may include machine control and process control functions. An example of a suitable commercially available control system is available from Sciaky lnc„ under the designation VV20XX. The control system may include a suitable computer control and interface (which may include one. or more micro-computers, servo drive modules, input/outpui modules, or signal conditioning module). The control system may include One or more suitable processors (e.g., a processor with at least one VME or other standard bus back plane), such as the 680X0 series Of processors (e.g., 68040) from Motorola, with the processors including onboard memory (e.g., Random Access Memory (RAM)): More preferably, an Intel© Pentium® processor may be used. The control system may include a user interface component (e.g,, suitable input/output hardware that .communicates with the processor and allows programming 28 of the processor, such as by a Microsoft Windows™ operating systems, of otherwise). The control system may include suitable software (e.g,, software available under the designation Sct'aky Weld 2GXX (e.g. W2000, W2010, VV2020) or some other W20 family of software). 2015275236 22 Dec 2015 £0089) The W20XX control system may be in signaling communication with one of more suitable computer (e.g., T7400 Workstation PC, by Deli) that may foe used to perform closed loop parameter adjustments sent to operate the overall system (e.g., a power supply (which may include a solid state power supply), ah electron beam gun, any detector or sensing device, any data acquisition electronics, or otherwise)). The control system may be in signaling communication with hardware, such as an energy emission device, a monitor, a work piece support, other hardware that is controilable according to the present teachings, or a combination thereof. £0090) Thus, the computer application software, computer system, and the closed loop electronic control device, or a combination thereof maybe in communication with the detector so that process parameters may be monitored as previously discussed herein and controlled. Controlling may be based upon a detected shape of a melt pooi deposit. For example* a detected shape may cause the control system to change a processing condition such as one that affects melt pool surface tension, a feed condition, or both. Surface tension may be a characteristic that is detected and upon which adjustments to processing conditions are made. £0091} The control device 20 may include a Linear PID (proportional-iniegral-denvative) style of control. The control device may be a single input single output system. The control device 20 may include a multi-input / multi-output (MlMO) routine which may have a variety of operating modes, it is appreciated that a fuzzy logic style of control may offerseveral advantages, for this process as may be well suited for use with a MiMO system as well as both linear and nfon-iinear processes. In such a control, input variables, output variables, or both, may be converted from hard scalar numbers to ‘fuzzy” sets, which are represented by a suitable linguistic terms (e.g.. a descriptive and/or relative terms, such as "big” or ’‘small"). Thus, the control may make it possible to convert actions that a manual operator may perform into an automated operation.

For example, the controller may interpolate and/or extrapolate input values, output values, or both by employing a series of “if-then* rules. Each variable may have Its own unique "fuzzy” set assigned to It, which may be amanged and/or processed independently of other variables, For example, a beam power control operation may be independent of an X-Y deflection operation. £0092) Examples of simple arid complex control inputs and control outputs may include one that monitors for a predetermined condition and then adjusts one or more (e.g., preferably at least two) processing parameters in response to information from the monitoring. For example* a 29

Simple Single Input Single Output. (SISQ) control may be employed where the melt pool width is monitored for a predetermined condition and the control then adjusts one or more processing parameters (e.g., an energy beam condition such as power) to alter the monitored condition- A Complex Multiple Input/Multiple Output control may include monitoring the melt pool width, melt pool shape, and/or peak temperature bias, Based upon information acquired, from the monitoring, the controller may then adjust one or more processing parameters (e.g,, at least two parameters, such as the energy beam condition, the wire feed rate, and/or beam deflection)· A dosed loop electronic control device may employ fuzzy logic, Past Fourier Transform (FFTj, software signal processing, or any combination thereof to alter a processing condition in response to a detected condition. 2015275236 22 Dec 2015 [0093) The time lapse between when a melt pool deposit is formed and when a condition is altered in response to a detected condition is rapid. For example, the response time may be about one minute or less, about 30 seconds or iess, about 10 seconds or less, about 5 seconds or less, or even about i second or less. Thus, substantially real time condition adjustment is possible, |0O94J For testing and verification, at least one accelerometer optionally may be attached to the equipment to measure the gravitational forces and accelerations. Additionally, the process parameters may be recorded on the same time basts as the process monitoring instrumentation outputs. Examples of process parameters that may be monitored are: sealed housing environmental parameters {for example, temperature); beam parameters (for example,current, voltage, deflection and focusing cosi parameters, raster patterns): vacuum levels (tor example, pressure level); rate and location parameters; and wire feeder control parameters (for example, rate, start, and stop). A computer, having a user interface, may be employed for commanding and controlling the fabrication process, A human operator may evaluate the overall operation of the energy emission device, the materia! delivery device, positioning mechanisms, vacuum operating parameters, or any combination thereof. Though the objective of the present invention is to form an automatic system, some aspects of the present invention may be used in a process that, requires human intervention. The closed loop electronic control device may be configured to make the appropriate command inputs through the monitoring system and control software, or both, to manage the various systems of the layer manufacturing process.

[0095) The present teachings also contemplate the possible use of an alignment fixture for use with an IM apparatus, and particularly an energy ©mission device. In general, an alignment fixture may be employed in a process of setting up the.LM apparatus, calibrating the LM apparatus, of both. The alignment fixture may be positioned relative to the LM apparatus while 30 adjustments are made to the orientation of one or more components of the LM apparatus. The orientation of the adjusted components may be fixed in a secure position and then the alignment fixture may be removed. 2015275236 22 Dec 2015 {0096J A suitable alignment -fixture may include one or more features for simuiating the position of one or more components of the LM apparatus relative to another, a site where a work piece may be located, or both. For example, an alignment fixture may include a support structure with a base portion and a guide surface portion. The alignment fixture may include an adjustable, height work piece support simulator carried on the support structure that raises and lowers relative to the base portion along the guide surface portion. The alignment fixture may include an energy emission device orientation simulator disposed.above the work piece support simulator on the support structure. The energy emission device orientation simulator may include an interface for alignment when mounting a detection device, an Interface for alignment when mounting a deflection coil, a focusing coil, or a combination thereof. The support structure may have a perimeter that defines an interior region that may be accessible from at least one side of the support structure. The base portion may include a base member, which may be a plate. The guide surface portion may include at least one geneiaity upright guide member. The at least one generally upright guide member may be a shaft. The at least one generally upright guide member may be temporarily or permanently mounted to the base member. The workpiece support simulator may include a member that is mounted on the at least one generally upright guide member and is guidingly translated on the guide member. The work piece support, simulator may include at least one plate having an opening through which the at least one generally upright guide member passes. The work piece support simulator may include a suitable bearing for allowing translation. For example, there may be at least one linear bearing disposed above arid/or below the mounted member. The work piece support simulator may include at least one position adjustable device that interferes with translation of the work piece support simulator. For example, the adjustable device may be; a collar that at least partially surrounds at feast one of the generally upright guide members^ The work piece;support simulator may include a plate having at least orie target alignment feature defined thereon for simulating a characteristic of the work piece support, a work piece on the support, or both. {0097] The orientation simulator may include at ieast one first plate attached toward an upper end the support structure. For example, the at least one first plate may be attached (e.g.« by press fit, weld, fastener, or otherwise) to the support structure via at least one shaft. The at least one first plate may have a (I) a generally upright wall for simulating mounting hardware for 31 a detector; (if) a second piaie disposed beneath the plate and at least partially in the interior portion for simulating mounting hardware:for a deflection coil; or( iij) both (i) and (ii). 2015275236 22 Dec 2015 [0038] in use, the fixture would allow vertical adjustment of components of the system. Further, the fixture structure allows it to receive ana or more components of the LM apparatus and support the components while an adjustment is made. For example, one or any combination of steps may be employed by loosening or otherwise releasing at ieast one fastening attachment of at ieast one component, supporting (e.g.„ in a substantially flush Fit) the at least one component on the alignment fixture while the at least one fastening attachment is in the loosened state, adjusting the orientation Of the at least one component, re-securing the least one fastening attachment of the at least one component.

[0039] With specific reference to FIG, 7. there is depicted In more particular detail an example of one such alignment fixture S10 In accordance with the present teachings. The alignment fixture 510 includes a support structure 512 including a base portion 514 and a guide surface portion 518. An adjustable height work piece support simulator 518 is carried on the support structure 512 that raises and lowers relative to the base portion along the guide surface portion 516.

[001 GO] An energy emission device orientation simulator 520 is disposed above the work piece support simulator 518 on the support structure 512, The energy emission device orientation simulator 520 may include a. first interface 522 fer alignment of mounting a detection device, a second interface 524 for alignment csf mounting of a deflection coil, or both. The support structure may have a perimeter that defines an interior region 526 that may be accessible from at least one side of: the support structure, The base portion may include a base member, which is illustrated as a plate 528. The guide surface portion 516 may include a number of generally upright guide shafts 530; [00101] The work piece support simulator 518 may include a member 532 that may be mounted on the at least one generally upright guide member and may be guidingly translated on the guide member. The work piece support simulator 518 may include a plate 534 that may have openings through which the guide shafts may pass, and which the plate may bear against the shafts. The work piece support simulator 518 is depicted as having multiple linear bearings 536 for allowing translation.

The work piece support: simulator 518 may also include a collar 538 that may interfere with translation of the work piece su pport simulator. The plate 534 of the work piece support simulator 518 may have at feast one target alignment feature 540 defined thereon for simulating a characteristic of the work piece support, a work piece on the support, or both. 32 [00102] the orientation simulator 520 is illustrated as having at least one first plate 542 attached toward an upper end the Support structure. The at feast one first plate 542 may have a generally upright wall 544for simulating mounting hardware for a detector and a second plate 545 disposed beneath the plate and at feast partially in the interior portion for simulating mounting hardware for a deflection coil, 2015275236 22 Dec 2015 [00103] The present invention may further provide a method (e.g., process) for layer manufacturing of a three-dimensional work piece. For example, the layer manufacturing process may include feeding raw material in a solid state to a first predetermined location. The raw materia! may be deposited onto a substrate (e.g,,. work piece support )6) as a moiten pool deposit under a first processing condition. The molten pool deposit may be monitored for a preselected condition (e.g., using the monitoring system as described previously). Information about the preselected condition of the monitored molten pool deposit may be compared with a predetermined desired value for the preselected condition of the monitored moiten pool deposit, such as by use of the closed loop control device previously described, and the first processing condition may be automatically altered (e.g,, by the closed loop control device) based upon information obtained from the comparing step. The moiten pool deposit may be solidified ,and/or allowed to solidify. The steps may be repeated at one or more second locations for building up layer by layer a three-dimensional work piece.

[00104] Any comparing step performed by the control deylce may be performed in any suitable manner. As indicated, one possible approach is to use IF Χ ΑΝΟ Y THEN .Z" rules, which may employ linguistic variables, [00105] The process may f urther indude the step of translating one or any combination Of the previously described apparatus components such as the material delivery device, the energy emission device, the work piece support (e.g., substrate), or the detector during use Of the apparatus, [00106] The step of feeding raw material may include advancing a metal wire feedstock (e.g., having an average diameter of less than about 5 mm) through a Wire feed device that may include a plurality of opposing spaced apart: rollers.

[00107] During the monitoring step, the detector 18 may optically monitor at least one moiten pool deposit, More particularly, the monitoring step may Include monitoring a condition associated with the molten pool deposit selected from bulk average temperature of the molten pool deposit, temperature gradient within the molten pool deposit, surface topography of the molten pool deposit, the presence of any liquid-solid interface in the molten pool deposit, surface profile of the molten pool deposit, chemical analysis of the molten pool deposit, or any 33 combination thereof. The preselected condition of the monitored molten pool deposit may be a predetermined value that is stored in memory of a computer processing system. The preselected condition of the monitored moifen pool deposit may also be a value of a previously measured molten pool deposit of the same or a different Work piece, or both. The information obtained from any monitoring step may be stored in memory and may he used subsequently to repair or replace a portion of the work piece. Any monitoring step may include monitoring at least one molten pool deposit in the absence of applying an external influence to induce osciiiations Of the weld pool deposit. 2015275236 22 Dec 2015 [00108] In the monitoring step, the orientation of the defector 1B, the refiective substrate, or both, relative to a first location about the melt pool, may be generally constant so that information about: the preselected condition of the molten poo! maybe obtained from generally similar locations of the melt pool as the melt pool progresses during the deposition. In another feature of the monitoring step, the orientation of the detector 18, the refiective substrate, or both relative to a first location about the melt pool may be generally variable so that information about the preselected condition of the molten poo! may be obtained from various locations (e,g.t progressively scanning) of the melt pool as the melt pool progresses during the deposition.

[00109] The step of automatically altering the first processing condition to a different processing condition may be performed by one or more electronic processing units (e.g., computer). The step of automatically altering the first processing condition to a different processing condition may include altering one or more conditions previously discussed herein. For example, the location of any device for supplying energy to melt the raw material; the location of any device used for feeding the raw'material; the location of any platform upon which a work piece is built; the pressure of any environment in which the processing .Is·performed;: the temperature of any environment in which the processing is performed; the voltage supplied to melt the raw material; the beam used for any electron beam source of energy for melting the raw material; the feed rate of the raw material; the composition of the deposited material; changing the temperature of the work piece; the temperature of the platform; or any combination thereof, may be altered., [00110] The methods may further include the step of repairing a damaged portion of the work piece by locating a stored monitored location that is relative to the damaged portion of the work piece, changing the preselected value to the stored monitored value; depositing, melted raw material at the damaged portion while monitoring the deposited maleriai until a second monitored value is determined that is the same as the preselected value; and advancing the deposition of melted raw material until a second monitored value is determined that is the same 34 as the preselected value. The method may Include the step of utilizing a proximity device (e.g,, laser) to measure the substrate distortion and subsequently map out the Z location for each deposition pass, The closed loop control may be;used to maintain a consistent melt pool, wherein height profiling may also be incorporated. Height profiling may be utilfeed in a pre-scan mode with a measurement accuracy of gehetdily up to about 0,8 mrrt (e.g.. about 0.10 mm to about 0.30 mm). 2015275236 22 Dec 2015 [00111J The establishment of processing parameters may be fay trial and. error, it may be based upon historical experience, it may be based upon one or more test methodology. By way of example, one approach may include comparing results of at least one deposition test run with known values obtained from a reference strupture having known values. The reference structure having known values may be placed in a. predetermined known location within the system, images may be taken with a detector and compared against known data about the reference structure having known values, and adjustments may be made to reduce the differences between the measured data and the known data. For example, the parameters may be varied above and below the baseline parameters (e.g.. irv terms of focus) to iteratively find optimal settings. Each test may produce one or mom digital file that eohtairis collected, data. A test log may be employed for manual entry by an observing operator.: Resulting images may be evaluated against .known values; (e.g. , contrast between known features/signal to noise, accuracy of features in the X-Y plane, and depth of field sensitivity in the Z^direc-tidn).

[001123 The present invention may include an article of manufacture made using the IM method, the LM apparatus, or both. The method of making the articles may result in a near net shape part that may be ready for finish machining. The article of manufacture may be an original equipment component, a replacement part, ora repaired original equipment component. The article may be heat-treated subsequent to its layer' by layer manufacture. The article may be an aircraft component, a rocket component, a marine craft component, a railcar component, an automotive vehicle component, a chemical processing component, a turbine component, or a space vehiclecomponent. (00113] In one embodiment, the article may exhibit a resulting substantially homogeneous microslructure, which is obtained throughout at least about 50% (and more preferably at least about 80%) of a section thickness of the article. For example, the article may be a substantially homogeneous mlprostructure having a plurality of columnar grains that is obtained throughout at least about 50% (and more preferably at least about 80%) of a section thickness of the article. 35 [00114] Relatively large articles (e.g,, greater than 7§G cm3) may be metallic and may .be made (e g., the processes being completed) in a period of less than about 15Θ hours (e.g., less than about 100 hours, preferably less than about 50 hours, or even more preferably less than about 20 hours) for each article. The article may be prepared directly from computer-aided design data. The article of manufacture may have an overall weight of at least about 10 kg, and may be made in a period of less than about 20 hours. For example, an article weighing about 60 to about 150 kg (or more) may be made in a period of no longer than about 20 hours. 2015275236 22 Dec 2015 [00115] The article may be prepared using a process, apparatus, or both that may bet free of a laser, prepared from a continuous deposition of each individuaHayer, prepared from an intermittent deposition of each individual layer, prepared in the absence of processing condition adjustment by a human during layer by layer buildup, or any combination thereof, it may be free of an ultrasonic detection method, [00118] Any depositing step may be performed so that the molten poof deposit undergoes a substantially continuous change in thermal condition in three-dimensions throughout the process. The steps may be performed at a rate sufficient to deposit successive layers at least about 2.5 kg of the raw material per hour, preferably at least 3 kg per hour (e.g., about 3,3 to about 6,8 kg per hour). The steps may be performed at a rate sufficient to deposit the raw material as a plurality of beads, that define successive layers having an average bead width of about 10 to about 15 mm (e.g., about 12.7 mm) at a. rate of at least about 25 cm of bead per minute (e.g,, about 35 to 60 cm per minute or higher). The process may be: interrupted for a period (e,g,, of bt least one minute, one hour, two hours, one day, or longer) prior-to completion of the Work piece, a rid may be resulted after complete sol idification of the work piece has occurred.

[00117] Any material delivery device may include a wire feed device (©,g, a. wire guide 28) that includes a plurality of opposing spaced apart rollers that advances a wire feedstock.

Any detector or sensing device may include a mechanism that intermittently acquires data about deposited material (e.g., at a rate faster than about 25 images per second). Any detector or sensing device may include a shutter mechanism located within an evacuated chamber that reduces exposure of the detector to vapors from the raw material.

[00118] The following process steps and features may be employed with any of the embodiments or devices taught herein. The following features may be employed separately or in combination with any of the embodiments taught herein. The process may use a raw material that includes a metal selected from one or any combination or alloy of metals selected from titanium, aluminum, iron, inconel, cobalt, stainless steel, niobium, tantalum, Copper, bronze, 36 brass, beryllium copper, or tungsten. The process may be interrupted for a period (e.g., of at (east one minute, one hour, two hours, one day, or longer) prior to completion of the work piece, and is resumed after complete solidification of the work piece has occurred. The monitoring step may include, employing as the image generating device, a digital camera, a charged coupled device.(CCD), a complementary metal oxide semiconductor (CMOS}, or a combination thereof, and includes generating images substantially in real time at a rate of at least 25 frames per second. The monitoring step may include monitoring a condition associated with the molten pool deposit1 from a location substantially overhead of the molten pool deposit, and optionally the condition is selected Mm bulk average temperature of the molten pool deposit temperature gradient within the molten pool deposit, surface topography of the moiten pool deposit, the presence Of any liquid-solid 'interface in the moiten pool deposit, surface profile of the moiten pool deposit, chemical analysis of the molten poof deposit,, or any combination thereof A preselected condition of the monitored moiten pooi deposit may be a predetermined value that is stored in memory of a computer processing system, the preselected condition of the monitored moiten pool deposit-is a value of a previously measured moiten pool deposit of the same or a different work piece, or both. The step of automatically altering the first processing condition to a different processing condition includes altering one: or more conditions selected from the location of any device for supplying energy to melt the raw material; the location of any device used for feeding the raw material·, the location of any platform upon which a work piece is buiit; the pressure of any environment in which the processing is performed; the temperature of any environment in which the processing is performed; the voltage and/or current supplied to melt the raw material; the beam used for any electron beam source of energy for melting the raw material (e,g., by changing the power to generate the begm , the Maim width, or both); the feed rate of the raw material; the feed angle of the raw material; the composition of the deposited material; changing the temperature of the work piece; the temperature of the platform; or any combination thereof. Trie information obtained from any monitoring step may be stored in memory and optionally is used subsequently to repair or replace a portion of the work piece, (00119] The following process steps and features may be employed with any of the embodiments or devices taught herein The following features may be employed separately or in combination With any of the embodiments taught herein. The process may further comprising the step of repairing a damaged portion of the work piece by locating a stored monitored location that Is relative to the damaged portion of the work piece; changing the preselected value to the stored monitored value; depositing melted raw material at the damaged portion while monitoring the deposited material until a second monitored value is determined that is the 2015275236 22 Dec 2015 37 same as the preselected value; and advancing the deposition of melted raw material until a second monitored value is determined that is the same as the preselected value. The monitoring step may include a step of protecting at least one exposed optical component Of a detector from vapor disposition build-up onto the exposed componentry, so that the vapor does not build up and adversely affect measurement Integrity, The monitoring step may include a step of cooling a detector by flowing a fluid In a housing of the detector for removing heat from the detector and the housing is separate and Spaced apart from any block with an aperture of any vapor protection device . The process may further comprise a step of aligning components of an apparatus for perfonrting the process using an alignment fixture. The step of monitoring may include a step of obtaining an optical image from a point of view that is substantially overhead of the meltdeposit The step of obtaining ah optical image wherein 0) the image from the substantially overhead view of the molten pool deposit is generally shaped to include a generally C-shaped portion with a generally circular or elliptical shaped portion, which corresponds to an image of the feed material, that is within the C-shaped portion, and possibly extending outside the opening Of the C-shaped portion, (ii) the step of automatically altering includes changing a process condition So that the shape of the image is substantially axially symmetrical; or both (i) and (ii). The orientation Of any feed of the raw material may be automatically changed in response to information obtained during the monitoring step. 2015275236 22 Dec 2015 [00120] The following features of the camera cooled housing may be employed with any of the embodiments taught herein. The following features may be employed separately or in combination With any of the embodiments taught herein. The cooled housing may include a front flange, seals, spacers, and back flange that are connected together by a fastening device, and the printed circuit boards are attached to the spacer by a connection device. The rear flange may include an opening for receiving ah energy source. The cooled housing may include'; (i) the mount adapter is located in the center of the front fiange, 0i):the mount adapter is secured in the front flange using a plurality of pins; or (iii) both (i) and (ii). The cooled.housing may include: a front flange, spacers, seals, and rear tonge that are generally rectangular-shaped:, The housing may have a height to width aspect ratio of about 2 to 1, preferably about 1.5 to 1, and more preferably about 1 to 1.2, The Inlet and outlet may be located on opposite sides of the front flange In generally opposing facing relationship to each other. The cooled housing may include; (i) the: spacers and seals include one or more heat sinks; (ii) one or more of the seals conduct heat; or both 0) and (ii). The coofed housing may include: a thermally conductive (e.g,, at least about 2 W/ni-K per A$TM 02214) polymeric-based interface sea! is employed between the flanges, and optionally wherein the interface seal includes a relatively 38 rigid polymeric (e..g,, acrylic) elastomarsurface layer having, a relatively low tack surface, and an underlying relatively flexible polymeric (e.g,., acrylic] support layer having a relatively low tack surface that, may be more tacky than the surface layer. The camera cooled housing may be used in any of the process steps described herein. 2015275236 22 Dec 2015 [00121) The following features-of the vapor protection device may be employed with any of the embodiments taught herein. The foilowing features may be employed separately or in combination With any of the embodiments taught herein, The vapor protection device may include a gas supply conduit connected with the at least orie fluid port for supplying the gas stream. The base portion and the. cover portion may be separable from each other for accessing a flow chamber defined in the block and through which the gas stream is flowed. The vapor protection device may include a protective window, which is optionally edge sealed by opposing spaced seals, is housed in the base portion between the apertures of the cover portion and the base portion arid the reflective substrate. The at least one fluid port may be defined by an elongated bore formed in a side wall of the base portion., and the bore has a longitudinal axis generally in the direction of elongation. The longitudinal axis of the elongated bore is substantially parallel with the optical path of an image between the reflective substrate and a camera. The vapor protection device taught herein may include a cooied housing taught herein. The vapor protection device may be carried on a common frame as with the copied housing, but is spaced apart from the cooied housing so that the vapor protective device is located generally overhead of the molten pool deposit white the cooled housing is longitudinally separated from the vapor protective device and any gas suppiy Sine for the vapor protection device is free of connection with the cooied housing. The common frame may Include a plurality of spaced apart elongated members along which the cooled housing, the vapor protection device or both may be mounted for adjustable and. biidabl© translation relative to each other,

The vapor protection device may be used in any of the process steps discussed herein.

[00122] The following features of the alignment fixture may be employed with arty of the embodiments taught herein. The foliowing features may be employed separately or in combination with any of the embodiments taught herein. The alignment fixture may include support structure has a perimeter that defines an interior region that is accessibie from at least one side of the support structure. The alignment fixture may include: (i) the base portion, includes a base member that is a plate; (it) the guide surface portion includes at least one generally upright guide member: or both (i) and: (ii). The alignment fixture may include; (i) the at least one generally upright guide member is a shaft: (ii) the at (east one generally uprightguide member is temporarily or permanently mounted to the base member; or both (I) arid (ii). The 39 work piece support simulator may include a member that is mounted on the at leastone genera lly upright guide member and is glidingiy translated on the guide member. The alignment fixture may include at least one plate having an opening through which the at least one generally upright guide member passes. The alignment fixture may include one or more suitable bearings for allowing translation, which optionally may be linear bearings disposed above or below the mounted member. The alignment fixture may include at least one position adjustable device that interferes with translation of the work piece support simulator, which optionally may be a collar that at least partially surrounds at least one of the generally upright guide members. The alignment fixiure m.ay include a plate having at least one target alignment feature defined thereon for simulating a eharaderlstic of the work piece support,, a work piece on the support, or both. The alignment fixture may be used with any of the teachings of the cooled camera housing, the vapor protection device, or both. The alignment fixture may be used with any of the process steps discussed herein. 2015275236 22 Dec 2015 [00123] The following features of the apparatusfor layer manufacturing a three-dimensional article may be employed with any of the embodiments taught herein. The following features may be employed separately or in combination with any of the embodiments taught herein. The material delivery device -includes a wire feed device that includes a plurality of opposing spaced apart rollers that advances a wire feedstock. The apparatus includes a detector that consists essentially of a camera that acquires images that are substantially overhead of the molten pool deposit at a rate of at least about 25 frames per second. The apparatus may be used with a cooled camera housing, a vapor protectiondevice, an alignment fixture, or a combination thereof. The apparatus may be used to perform any of the process steps described herein. The apparatus may assembled using an alignment fixture described herein. The apparatus may be used to manufacture an original equipment component, a repaired original equipment component, or a replacement component made using the process described herein.

[00124] The following features of ah article of manufacture may be manufactured using any of the embodiments taught herein. The following features may be employed separately or in combination with any of the embodiments taught, herein. The article of manufacture may be heat-treated subsequent to its layer by layer manufacture. The article may be an aircraft component, a rocket component, a marine craft component, a railcar component, an automotive vehicle component, a chemical processing component, a turbine component; or a space vehicle component; and wherein the article is metafile. 40 {00125] Structural relations, proportions, dimensions and geometries shown in the accompanying drawings ard; part of the teachings herein, even if not articulated verhaiiy in the present detailed description. The teachings herein also contemplate variations to any relative proportions and dimensions shown in the drawings; e.g,, variations within about ± 10%, about ± 25%, or even about ± 50% are possible. 2015275236 22 Dec 2015 [00126] Unless;otherwise-.stated, ail ranges include both endpoints and all numbers between the endpoints, The use of “about” or "approximately* in dohnection with a range applies to both ends of the range. Thus, “about 20 to 30“ is intended to cover “about 20 to about 30", inclusive of at least the specified endpoints. The specification of ranges Herein aiso contemplates individual amounts falling within the range. Thus, for example, a range of 10 to 1S contemplates individually the amounts of 10,11,12,1.3, 14, and 15, [00127] The disclosures of'alt articles and references* including patent applications and publications, are incorporated by reference for aii purposes. References to the term “consisting essentially of to describe a combination shall include the elements, ingredients, components dr steps identified, and such other elements ingredients, components, or steps that do not materially affect the basic and novel characteristics of ihe combination. The use of the terms “comprising" or “including” to describe combinations of elements, ingredients, components or steps herein also contemplates embodiments teal consist essentially of, or even, consist of, the elements, ingredients, components or steps.

[00128] Piural elements, ingredients, components, or steps can be provided by a single integrated element, ingredient, component, or step. Alternatively, a single integrated element, ingredient, component or step might be divided into separate; plural elements, ingredients, components or steps. The disclosure of "a" or “one” to describe an element, ingredient, component or step is not intended to foreclose additional elements, ingredients, components or steps. Likewise, arty reference to “first” or “second" items is not intended to foreclose additional items (e.g,, third, fourth, or more items); such additional items are also contemplated, unless otherwise stated. Any references herein to elements or metals belonging to a certain Group refer to the Periodic Tabie of the Elements published and copyrighted by CRC Press, (nc., 1989. Any reference to the Group or Groups shall be to file Group or Groups as reflected in this Periodic Table of the Elements using the lUPAG system for numbering groups.

[00129] The teachings of the reiative positions, orientations, and proportions of components depicted in the accompanying drawings aiso form part of the teachings herein even if not expressly stated, 41 |0ΰ13Ο| It is understood that the above description is intended to be illustrative and net restrictive. Many embodiments as well as many applications besides the examples provided will be apparent to those of skill in the art upon reading the above description. It is further intended that any combination of the features of different aspects or embodiments of the invention may be combined. The scope of the invention should, therefore, be determined not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope Of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are incorporated by reference for all purposes. The omission in. the following claims of any aspect of subject matter that is disclosed herein is not a disclaimer of such subject matter, nor should It be regarded that the inventors did not consider such subject matter to be part of the disclosed inventive subject matter. 2015275236 22 Dec 2015 42

Claims

1. An apparatus for layer manufacturing a three-dimensional work piece, comprising: a) a housing defining a chamber capable of evacuation and within which a metallic work piece is formed layer by layer from a plurality of successively deposited molten pool deposits, the housing enclosing: a. an electron beam gun that melts a metal feed material; b. a table upon which the metallic work piece is formed, the table and the electron beam gun being adjustably spaced relative to each other so that as the metallic work piece is formed layer by layer from the plurality of successively deposited molten pool deposits, the spacing incrementally increases; c. an optical assembly including; i. a first enclosure, ii. optics for reflecting light housed in the first enclosure, iii . an aperture in a wall of the first enclosure for allowing access, into the first enclosure, of light emitted by one or more molten pool deposits so that the light reaches the optics, and iv. a vapor protection device that substantially avoids build-up of metal vapor on the optics during operating of the apparatus; d. an imaging device including: i. a detector array, ii. thermally regulated electronic componentry, and iii. a second enclosure that substantially encloses the detector array and the thermally regulated electronic componentry, and also includes an opening through which light that is emitted by one or more molten pool deposits and is reflected from the optical assembly can communicate with the detector array; and e. a frame that carries the enclosures of the optical assembly and the imaging device in spaced apart relation from each other so that the aperture of first enclosure is substantially overhead of the molten pool deposit, and the first and second enclosures are separated from each other; b) a closed loop control device configured to automatically adjust one or more processing parameters of the apparatus in response to data obtained from the imaging device.

2. The apparatus of claim 1, wherein the vapor protection device, includes: (a) a block that includes a base portion and a cover portion, the base portion including at least one fluid port that receives a gas stream that is controllahly regulated, the base portion and the cover portion each having an aperture that is generally axially aligned with each other and is adapted to be axially aligned substantially overhead of the molten metal pool deposit; (b) at least one reflective substrate that is in optical communication with at least one of the apertures of the cover portion, or the base portion, for reflecting an image that passes through such aperture to a separately housed optical imaging device that records the image; wherein the gas stream enters the at least one fluid port and exits the block through one of the apertures, and provides an optically transparent protective barrier to prevent passage of metal vapor through the other aperture.

3. The apparatus of claim 2, wherein the system includes a gas supply conduit connected with the at least one fluid port for supplying the gas stream.

4. The apparatus of claim 2, wherein the base portion and the cover portion are separable from each other for accessing a flow chamber defined in the block and through which the gas stream is flowed.

5. The apparatus of claim 2, wherein a protective window is housed in the base portion between the apertures of the cover portion and the base portion and the reflective substrate.

6. The apparatus of claim 5, wherein the protective window is edge sealed by opposing spaced seals.

7. The apparatus of claim 2, wherein the at least one fluid port is defined by an elongated bore formed in a side wall of the base portion, and the bore has a longitudinal axis generally in the direction of elongation.

8. The apparatus of claim 7, wherein the longitudinal axis of the elongated bore is substantially parallel with the optical path of an image between the reflective substrate and a camera.

9. The apparatus of claim 1, wherein the detector is located in a cooled camera housing comprising: a front flange; at least one spacer pad connected to the front flange; at least one seal adj oining the spacer pad; a rear flange connected to the front flange and sandwiching therebetween the at least one spacers and seals; wherein the front flange, the at least one seal, the at least one spacer pad, and the rear flange form an interior cavity; one or more printed circuit boards located within the interior cavity; an image detector; and wherein at least one of the flanges includes an inlet, an outlet, a fluid passage between the inlet and the outlet through which a heat exchange fluid is passed for cooling the printed circuit boards during their operation.

10. The apparatus of claim 2, wherein the detector is located in a cooled camera housing comprising: a front flange; at least one spacer pad connected to the front flange; at least one seal adjoining the spacer pad; a rear flange connected to the front flange and sandwiching therebetween the at least one spacers and seals; wherein the front flange, the at least one seal, the at least one spacer pad, and the rear flange form an interior cavity; one or more printed circuit boards located within the interior cavity; an image detector; and wherein at least one of the flanges includes an inlet, an outlet, a fluid passage between the inlet and the outlet through which a heat exchange fluid is passed for cooling the printed circuit boards during their operation.

11. The apparatus of claim 9 or 10, wherein the at least one of the flanges includes a mount adapter.

12. The apparatus of claim 9, wherein the front flange, seals, spacers, and back flange are connected together by a fastening device, and the printed circuit boards are attached to the spacer by a connection device.

13. The apparatus of claim 9, wherein the rear flange includes an opening for receiving an energy source.

14. The apparatus of claim 11, wherein (i) the mount adapter is located in the center of the front flange, (ii) the mount adapter is secured in the front flange using a plurality of pins; or (iii) both (i) and (ii).

15. The apparatus of claim 9, wherein the front flange, spacers, seals, and rear flange are generally rectangular-shaped.

16. The apparatus of claim 9, wherein the inlet and outlet are located on opposite sides of the front flange in generally opposing facing relationship to each other.

17. The apparatus of claim 9, wherein (i) the spacers and seals include one or more heat sinks; (ii) one or more of the seals conduct heat; or both (i) and (ii).

18. The apparatus of claim 9, wherein a thermally conductive polymeric-based interface seal is employed between the flanges.

19. The apparatus of claim 18, wherein the interface seal includes a relatively rigid polymeric elastomer surface layer having a relatively low tack surface, and an underlying relatively flexible polymeric support layer having a relatively low tack surface that is more tacky than the surface layer

20. The apparatus of claim 9, wherein the frame includes a plurality of spaced apart elongated members along which the cooled housing, the vapor protection device or both is mounted for adjustable and slidable translation relative to each other.

21. The apparatus of claim 10, wherein the detector is a digital camera, a charged Coupled device, a complementary metal oxide semiconductor, or a combination thereof, and generates images substantially in real time at a rate of at least about 25 frames per second.

22. The apparatus of claim 21, wherein the pre-selected condition that is monitored is selected from bulk average temperature of the molten pool deposit, temperature gradient within the molten pool deposit, surface topography of the molten pool deposit, the presence of any liquid-solid interface in the molten pool deposit, surface profile of the molten pool deposit, chemical analysis of the molten pool deposit, or any combination thereof.

23. The apparatus of claim 22, wherein the closed loop electronic control device controls one or more components of the apparatus by altering one or more process conditions selected from a location of any device for supplying energy to melt the raw material; a location of any device used for feeding the raw material; a location of any platform upon which a work piece is built; pressure of any environment in which the processing is performed; temperature of any environment in which the processing is performed; voltage and/or current supplied to melt the raw material; a beam used for any electron beam source of energy for melting the raw material; feed rate of the raw material; feed angle of the raw material; composition of the deposited material; changing a temperature of the work piece; temperature of the platform; or any combination thereof.