JPH0814461B2 - Method and apparatus for hot isostatic pressing under oxidizing atmosphere - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is for forming an object to be treated such as a powdered sintered alloy or a ceramic by applying an isotropic high pressure in an oxidizing atmosphere at a high temperature. Method and device (hereinafter referred to as HIP device)
Regarding

(Prior Art) Conventionally, as shown in FIG. 8, a HIP device is composed of a high-pressure container 31 for enclosing high-pressure gas, a heating device 32 installed in the container 31, and an object mounting table 33. The high-pressure container 31 includes an upper lid 34 and a lower lid 35, and the heating device 32 is a heating element 36 and a power supply device.
37 and a heat insulating layer 38.

When a material having a large electric resistance (for example, zirconia) is used for the heating element 36 in a low temperature portion, the resistance change is large, and therefore a power supply device 37 capable of heating from room temperature to an effective heating temperature (about 100 times) is required.

Therefore, a HIP device has been proposed in which the heating device 32 is preheated to a temperature at which it can be energized by a preheating device 39 (see, for example, JP-A-63-23732).

This HIP device, as shown in FIG.
Is composed of an inner layer heat insulating tube 40 and an outer layer heat insulating tube 41, and a heating element (metal heater) 42 arranged between these inner and outer layer heat insulating tubes 40, 41, and a preheating device 39 is provided on the lower lid 35. While being placed, the heating device 32 formed of a ceramic heater is placed inside the inner layer heat insulating cylinder 40, and the object to be treated 20 is placed on the heating device 32 via the insulating plate 43. Has become. In addition, a lead wire 44 for preheating and heating is inserted through the lower lid 35 and connected to a power supply device (not shown).

Then, in the state shown in FIG. 9, prior to energization of the heating device 32, the heating device 32 and the object to be treated 20 are heated by the preheating device 39.
When the heating element atmosphere of the heating device 32 reaches a temperature range in which power can be supplied, that is, a temperature at which current can be supplied, the heating device is heated.
It energizes 32 and heats up to the HIP processing temperature.

(Problems to be solved by the invention) By the way, in the latter conventional device, since the preheating and heating devices 32 and 39 are housed in the high-pressure container 31, extra electrodes are required, and a high-pressure gas seal is provided. The number of parts is increased, the inside of the high-pressure container 31 is complicated, and the heating element 42 of the preheating device 39 and the heating device are included.
Since the inner-layer heat insulating cylinder 40 is interposed between 32, there is a problem that the preheating efficiency is poor and the processing chamber becomes narrow.

The present invention has been made in view of the above situation, and an object thereof is to have a simple structure in a high-pressure vessel, easy maintenance, high preheating efficiency, and a wide processing chamber. (EN) A method and apparatus capable of hot isostatic pressing under an oxidizing atmosphere.

(Means for Solving the Problems) In order to achieve the above object, the present invention takes the following technical means.

That is, according to the method of the present invention according to claim 1, in the high-pressure vessel 1 in which the heating element 10 is provided with the heating device 9 made of a material having a large electric resistance in a low temperature portion, the object 20 to be treated is subjected to high pressure in an oxidizing atmosphere, etc. In the method for forming by applying a directional high pressure, the heating element 10 of the heating device 9 is preheated in the high pressure container 1.
It is preheated to a predetermined temperature by means of 14, after which the preheating device 14 is removed, then the object to be treated 20 is inserted into the heating element 10 of the heating device 9 and main heating is carried out in the high-pressure container 1 for molding. It is what

Further, in the method of the present invention according to claim 2, in the high pressure vessel 1 in which the heating element 10 is made of a material having a large electric resistance in a low temperature part, the object 20 to be treated is subjected to high pressure in an oxidizing atmosphere. In the method for forming by applying a directional high pressure, the heating element 10 of the heating device 9 is preheated outside the high pressure container 1 and then inserted into the high pressure container 1, and then the object 20 to be processed is heated by the heating device. It is characterized in that it is inserted into the heating element 10 of No. 9 and is heated and molded in the high-pressure container 1 by main heating.

Further, in the device of the present invention according to claim 3, the heating element 10 is provided in the high pressure container 1 provided with the heating device 9 made of a material having a large electric resistance in a low temperature part, and the object 20 to be treated is subjected to high pressure in an oxidizing atmosphere. In the apparatus for forming by applying a directional high pressure, the heating device 9 includes a heat insulating layer 11 outside a heating element 10 connected to a power supply device 13, and a preheating device 14 is provided inside the heating element 10 of the heating device 9. The heating element 10 is removable and the preheating device 14 is removed.
It is characterized in that the object to be processed 20 can be inserted therein.

Further, the device of the present invention according to claim 4 is the device invention according to claim 3, wherein the heating element 10 of the heating device 9 and the outer heat insulating layer 11 are separable, and the heat insulating layer 11 is the high pressure container 1.
It is characterized by being retained inside.

(Operation) According to the present invention, the heating device 9 is directly preheated by the preheating device 14, heated to a temperature at which it can be energized and then energized to generate heat, and the workpiece 20 is inserted into the heating device 9, High pressure vessel 1
A high-pressure gas is sealed inside, and isotropic high pressure is applied in an oxidizing atmosphere, and the mixture is heated to the processing temperature for molding.

In this preheating, the heating element 10 of the heating device 9 is the preheating device.
The heating element 15 of 14 heats directly and efficiently without passing through a heat insulating layer.

It should be noted that although the preheating by the preheating device 14 is completed and the heating device 9 is opened to the atmosphere when the preheating device 14 is removed, the heating device 9 is in the energized heat generation state and does not cause a temperature drop. Also, there is no fear of oxidation.

(Example) Hereinafter, the Example of this invention is described based on drawing.

1 and 2 show a first embodiment device of the present invention,
FIG. 1 is a preheating state, and FIG. 2 is a sectional view in the main heating state.

Reference numeral 1 denotes a high-pressure container, a container body 2, an upper lid 3 that is detachably attached to the upper end of the container body 2, a lower outer lid 4 that is detachably attached to the lower end of the container body 2, and preheating that is detachably replaceable to the lower outer lid 4. Lower lid for
5A and lower lid 5B for main heating, and seal members 6, 7, 8
Due to the sealed structure.

Reference numeral 9 denotes a heating device, a heating element 10 made of a material having a large electric resistance in a low temperature portion, for example, a ceramic material (zirconia, thoria, etc.) having a negative temperature coefficient of volume resistivity, and a heating element.
It is composed of a heat insulating layer 11 (which uses porous zirconia or the like as a heat insulating material) that surrounds the outside of 10, and is supported on the lower outer lid 4 and attached to the heating element 10 in a penetrating manner on the lower outer lid 4. An electrode rod 12 is connected to the electrode rod 12, and an electrode device 13 is connected to the electrode rod 12.

14 is a preheating device, such as a preheating heater such as Ni-Cr alloy, Fe
-Al-Cr alloy, platinum alloy, SiC, etc. preheating heating element 1
5 and a heating element support member 16, and the support member 16 is provided upright at the center of the upper surface of the lower inner lid 5A for preheating. The preheating heating element 15 is connected to a preheating electrode rod 17 that is penetratingly attached to the preheating lower lid 5A, and the electrode rod 17 is connected to a preheating power supply device 18. Since the lower lid 5A for preheating is used only for preheating and is not filled with high-pressure gas,
It is simple and lightweight and has no sealing member.

The preheating device 14 is inserted inside the heating device 9, and the heating elements 10 and 15 are directly opposed to each other without a heat insulating layer interposed therebetween.

Reference numeral 19 denotes an object placing table, which is placed at the center of the upper surface of the main heating lower middle lid 5B, and the object 20 is placed on the table 19.

The lower lid 5B for main heating has no electrode rod or the like, and has a simple structure in which the seal member 8 is fitted to the outer peripheral fitting surface, so that reliable sealing can be performed. Target.

Next, a method of performing the hot isostatic pressing process on the object to be processed 20 in an oxidizing atmosphere by the apparatus of the first embodiment will be described.

First, as shown in FIG.
14 is inserted, the preheating lower inner lid 5A is fitted and attached to the lower outer lid 4, and the preheating power source device 18 energizes the preheating heating element 15,
Preheat in the atmosphere. When the temperature in the high-pressure container 1, that is, the temperature of the heating element 10 for main heating reaches a temperature (about 1200 ° C.) at which electricity can be applied, the heating element 10 is simultaneously energized by the power supply device 13, and then the preheating device 14 is promptly turned on. Withdraw from the high-pressure container 1. Next, the object to be treated 20 is inserted from the lower end of the container body 2 into the inside of the heating device 9 in the high-pressure container 1 together with the placing table 19 on which it is placed and the lower inner lid 5B, and is set and shown in FIG. After the state, the high-pressure container 1 is filled with high-pressure gas and heated to the processing temperature, and the process proceeds to the isotropic pressure molding step.

As the high-pressure gas, an atmosphere gas in which an oxygen gas is mixed with an inert gas such as argon gas in an optimum volume ratio according to the type of the object 20 to be processed is used, and the inside of the high-pressure container 1 is set to an oxidizing atmosphere. It

Therefore, after the preheating is completed, the lower end of the container body 2 is opened to the atmosphere, but there is no fear of oxidation of the structure 20 and the object 20 to be processed in the high-pressure container 1 and moreover, since the heating element 10 is heating the object to be processed. During the work of inserting and setting the object 20 in the high-pressure container 1, the temperature inside the high-pressure container 1 does not drop.

3 to 6 show the apparatus of the second embodiment of the present invention, FIG. 3 is an overall sectional view of the state of the main heat treatment, and FIG. 4 shows a part of the heating apparatus taken out from the high-pressure container during preheating. FIG. 5 is a cross-sectional view of the state in which the heating element of the heating device is preheated, and FIG. 6 is a cross-sectional view of the lower middle lid and an object to be treated placed on the lower lid via a mounting table.

In the second embodiment, the heating element 10 of the heating device 9 and the heat insulating layer 11 are separable, the heat insulating layer 11 is hung on the lower surface of the upper lid 3 via the hanging member 21, and the heating element 10 is used for main heating. The heating element 10 is attached to the upper surface of the lower outer lid 4 so that it is preheated outside the high-pressure container 1. And the preheating device 14
As shown in FIG. 5, is erected on a support ring 22 that is detachably fitted on the outer peripheral upper portion of the lower lid 4, and
The heating element 15 is installed inside the 16 and the heating element 10 for main heating is attached.
It is designed to heat this from the outer circumference of the
A heat insulating cover 23 is attached to the outside of 16. Further, the preheating electrode rod 17 is attached to the support ring 22 in a penetrating manner.

Next, a method of performing hot isostatic pressing treatment on the object to be processed 20 in an oxidizing atmosphere by the apparatus of the second embodiment will be described.

First, as shown in FIG. 4, the heating element 10 of the heating device 9 is extracted from the container body 2 together with the lower outer lid 4, and the high pressure container 1
And the heat insulating layer 11 is left suspended in the high-pressure container 1. On the other hand, as shown in FIG. 5, the heating element 10 of the heating device 9 is temporarily placed outside the high-pressure container 1, is surrounded by the preheating device 14 from the outer periphery, and is preheated by the preheating power supply device 18. To preheat in the atmosphere. At this time, the object 20 to be processed, the lower inner lid 5B, and the like shown in FIG. 6 can be inserted into the heating element 10 and the lower outer lid 4 can be fitted and set in the lower outer lid 4. .

When the temperature of the heating element 10 for main heating reaches a temperature at which energization is possible, at the same time, after energizing the heating element 10 by the power supply device 13,
The preheating device 14 is quickly removed, the object 20 to be processed placed on the lower middle lid 5B is inserted into the heating element 10 together with the lid 5B, and the lower inner lid 5B is set on the lower lid 4. Then, the object to be treated 20 and the like together with the heating element 10 are inserted into the high-pressure container 1, and the lower lid 4 is fixed to the container body 2 to the state shown in FIG.
A high-pressure gas is sealed inside and heated to the processing temperature, and the process proceeds to the isotropic pressure molding process.

FIG. 7 illustrates a method of preheating the heating element 10 of the heating device 9 outside the high-pressure container 1 using the apparatus of the first embodiment. The heat insulating layer 11 of the heating device 9 is integrated with the heating element 10. In a state in which it is assembled in a mechanical manner, it is taken out from the high-pressure container 1, a preheating device 14 is inserted and set in the heating device 9, and preheating is performed. Then, when the preheating is completed, the heating element 10 of the heating device 9 is energized, the preheating device 14 is quickly removed, and then the object to be treated 20 is put together with the lower inner lid 5B.
Is set in the heating device 9, and then the heating device 9 and the object to be treated 20 are both inserted into the high-pressure container 1 to fix the lower lid 4 to the container body 2, and the high-pressure gas is supplied into the high-pressure container 1. Enclose and heat to processing temperature. In this way, the device of the first embodiment is configured such that the heating element 10 of the heating device 9 is provided inside or outside the high-pressure container 1.
Can be preheated.

In each of the above-described embodiments, the temperature inside the high-pressure container 1 during the hot isostatic pressing process tends to be lower in the lower part, so that the temperature control is naturally performed.

During the hot isostatic pressing, the upper lid and the lower lid receive the axial force in the axial direction of the container by the frame frame (not shown).

(Effects of the Invention) As described above, the present invention preheats the heating element 10 of the heating device 9 by the detachable preheating device 14 when performing the hot isostatic pressing in an oxidizing atmosphere. Therefore, it suffices to provide a power supply device that matches the electric resistance value of the heating element 10 in a high temperature state, which is extremely economical. Also, the object
Since 20 is inserted into the heating device 9 after the preheating device 14 is removed, the processing space can be increased, the structure inside the high-pressure vessel 1 can be simplified, and the sealing portion at the time of pressurization processing does not increase (preheating electrode Since there is no seal on the part), maintenance is easy.

Further, since the heat insulating layer 11 is provided outside the heating element 10 of the heating device 9 and there is no heat insulating layer inside the heating element 10, the preheating device
It is directly heated by 14 and therefore has good preheating efficiency.

The heating device 9 can be preheated outside the high-pressure container 1 and inserted into the high-pressure container 1 together with the object 20 to be processed and set.

[Brief description of drawings]

1 and 2 show a first embodiment of the apparatus of the present invention. FIG. 1 is a sectional view in a preheating state, FIG. 2 is a sectional view in a main heating state, and FIGS. FIG. 3 shows a cross-sectional view in the main heating state, FIG. 4 is a cross-sectional view in which a part of the heating device is taken out from the high-pressure container during preheating, and FIG. 5 is a heating element preheating of the heating device. 6 is a cross-sectional view of the lower middle lid on which the object to be processed is placed, and FIG. 7 is a cross-sectional view of the first embodiment apparatus in which the heating device is taken out of the high-pressure container and preheated. 8 and 9 are sectional views showing a general structure of a conventional example, and FIG. 9 is a partially omitted sectional view of a conventional example in which a preheating device is incorporated in a high-pressure container. 1 ... High-pressure container, 9 ... Heating device, 10 ... Heating element, 11 ...
… Thermal insulation layer, 14 …… Preheating device, 20 …… Object to be processed.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location C04B 35/645

Claims (4)

[Claims] 1. An object to be treated (20) is heated under high pressure in an oxidizing atmosphere in a high-pressure container (1) provided with a heating device (9) whose heating element (10) is made of a material having a large electric resistance in a low temperature part. In the method for forming by applying isotropic high pressure, the heating element (10) of the heating device (9) is preheated to a predetermined temperature by a preheating device (14) in the high pressure container (1), and then, After removing the preheating device (14), the object to be treated (20) is inserted into the heating element (10) of the heating device (9) and main heating is performed in the high-pressure container (1) for molding. Method for hot isostatic pressing under an oxidizing atmosphere. 2. An object to be treated (20) is stored under high pressure in an oxidizing atmosphere in a high-pressure container (1) equipped with a heating device (9) whose heating element (10) is made of a material having a large electric resistance in a low temperature part. In the method for forming by applying isotropic high pressure, the heating element (10) of the heating device (9) is preheated outside the high pressure container (1) and then inserted into the high pressure container (1), After that, the object to be treated (20) is inserted into the heating element (10) of the heating device (9), and main heating is performed in the high-pressure container (1) to form the hot isostatic pressure in an oxidizing atmosphere. Pressure molding method. 3. An object to be treated (20) is heated at a high temperature in an oxidizing atmosphere in a high-pressure container (1) provided with a heating device (9) whose heating element (10) is made of a material having a large electric resistance at a low temperature portion. In the apparatus for forming by applying isotropic high pressure, the heating device (9) includes a heat insulating layer (11) outside a heating element (10) connected to a power supply device (13), The preheating device (14) is detachable in the heating element (10) of 9) so that the object to be treated (20) can be inserted into the heating element (10) from which the preheating device (14) has been removed. A hot isostatic pressurizing device in an oxidizing atmosphere. 4. The heating element (10) of the heating device (9) and the outer heat insulating layer (11) can be separated from each other, and the heat insulating layer (11) is held in the high pressure vessel (1). 3. The hot isostatic pressurizing device in the oxidizing atmosphere according to 3.