JPS6056761B2 - Method and apparatus for sintering and forming powder and granular materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In sintering powder, the present invention applies pressure to parts and sinters them by applying electricity, and this process is performed continuously or in stages to form the entire body into any size and shape. The present invention relates to a method and apparatus for obtaining a strongly shaped sintered body.

Conventionally, in order to obtain a sintered body, there has been a method and an apparatus in which a mold is filled with the required powder to be sintered, pressure-molded in a free state, and then heated and sintered. most commonly practiced. In addition, as a heating method, a method has been proposed in which powder is filled in a mold, pressure-molded, and electricity is applied to cause discharge between the powder to sinter. In addition, when the shape of the sintered body is complex, the pressing mold can be divided into sections and the pressing force can be adjusted for each divided mold so that the pressing force can be applied to each part of the mold at any desired strength. It is proposed to do so. According to these proposals, a relatively strong molded sintered body can be obtained, but it is also possible to obtain an energy density that is appropriate for each internal part, depending on the dimensions, shape, and strength required for each part, and suitable for minute changes in shape. No proposal has yet been made for sintering by pressurizing the material with an arbitrary pressure difference inside. In the present invention, the powder filled in a mold, etc. is partially pressurized, and the internal pressure difference caused by the partial pressurization is moved and applied in time, which could not be obtained with conventional pressure sintering. The purpose is to obtain a sintered compact having an appropriate internal energy density. Another objective is to obtain a molded body that increases crystallinity more rapidly and becomes stronger than conventional sintered bodies. Another purpose is to obtain a sintered body of better quality in any direction of the X-axis, Y-axis, and Z-axis. Another objective is to obtain a sintered body with complicated dimensions and shape. Another purpose is to improve the efficiency of the energy required for sintering. Another purpose is to enable easy application of NC control. In the present invention, a mold filled with powder to be sintered is placed on a table.

Detachably fixed to the stand. The platform is horizontally oriented, i.e.
With a fluid pressure cylinder mechanism or a tension feed mechanism in the X-axis and Y-axis directions, and in the vertical direction, that is, the Z-axis direction,
It is a movable structure. Attach one electrode to the stand,
The other electrode is attached to the surface of the object to be sintered, and both electrodes are aligned in the horizontal and vertical directions, that is, the X axis, the Y axis, and the Z axis.
The structure is movable in the axial direction. The power source is direct current, alternating current,
Use pulse current, high frequency current, or a combination of these. Electricity is applied to the filled body to be sintered under appropriate pressure, heating it by interpowder discharge to bring about an ionization effect, and at the same time generating Joule heat and heating it,
Sintering and forming while applying internal pressure. Electricity is applied to the initial positions of both electrodes to cause sintering, the table is moved, the position of the pair of electrodes is changed relative to the sintered part, the position of the sintered part is changed by the application of current, and the process is gradually continued. The whole is then partially sintered and sintered, possibly by changing the pressure or power supply. Also, during sintering or as a post-sintering treatment, , a mechanical stress is applied between the sintered powders at each predetermined portion.Also, the pressure difference is changed and the movement is made to vary depending on the area or location where the pressure difference is different.Also, as mentioned above, A sintered body or a sintered body formed by dividing the desired thickness into several minutes of thickness formed by other conventional methods is stacked in layers to create pressure differences that differ locally as described above. sintered into one piece with
It is also possible to obtain a sintered body with a desired size and shape. Next, the present invention will be described with reference to examples.

FIG. 1 is an explanatory front view of one embodiment of the present invention.

FIG. 2 is a front cross-sectional view of another applied embodiment of the electrode and sintered part of the present invention, and FIG. 3 is a front cross-sectional view of another applied example of the lifting and lowering of the electrode of the present invention. In FIG. 1, a sintered powder 18 is filled in a sintering container 19 in the center, and an upper lid body 18 is filled with the sintered powder 18.
Cover with S and bring the electrode E1 into contact. An electrode E2 is brought into contact with the bottom surface of the container 19, and a power supply S and connection parts 14, 15 are connected to each other.
By using direct current, alternating current, high frequency current, pulsed current, or a combination of these currents, electricity is applied between the sintered particles,
Sintering is performed by generating electric discharge heating, Joule heat, and ionization. The container 19 containing the sintered powder 18 has a structure that can be moved in the horizontal X direction by a fluid cylinder block X1, an axis X3, a shaft head X6, and a support head X9, which move the container 19.

These mechanisms are mounted and supported by the frame 3. The block E3 equipped with the electrode E1 is movable in the horizontal direction by the fluid cylinder block X1 mounted on the frame 3, the shaft X4, and the shaft head X7, and the block E4 equipped with the electrode E2
are the fluid cylinder X2 loaded on the frame 3, the shaft X5,
The shaft head X8 allows it to be moved in the horizontal direction relative to the block E3, either in the same way or independently.

Further, the unit Y shown in a circle with a dotted line in the figure is the cylinder block X. ．． Similarly to Xl and X2, the container 19 is moved in the horizontal Y-axis direction perpendicular to the axial direction of the cylinder block
, E2 are also made movable in the horizontal direction perpendicular to the axial direction of the cylinder block X. Further, in the vertical direction, a mechanism mounted on the frame 3 is used. It has a structure in which a sliding support plate Z9 for the block E3 is pushed and pulled by a fluid cylinder block Z1, a shaft Z3, and a shaft head Z6 on the upper part to raise and lower the block E3, thereby raising and lowering the position of the electrode E1. In addition, the lower part includes the fluid cylinder block Z2, the shaft Z male shaft head Z
7. The structure is such that the block E4 can be raised and lowered by pushing and pulling the sliding support plate Z9 for the block E4, and the position of the electrode E2 can be raised or lowered. The sliding support plate Z9 is fixed in the horizontal direction (left and right) and is movable in the vertical direction (up and down) with shaft heads Z6 and Z7.
The circuits 4 and 5 pass an arbitrary combination of currents from the power supply S to the connections 14 and 15, and connect the electrodes El and E.
2 is energized. The above cylinder blocks X, Y, Z
1, Z2, Xl, and X2, it is possible to use a mechanism in which each actuating block, for example, E3, E4, or the container 19, and the sliding plate Z9 are moved by a pulse motor and a screw mechanism. It is possible to connect the NC control mechanism 10 to each of the movement mechanisms already described, control and operate each mechanism, perform desired movement and energization, and perform sintering.

In FIG. 1, from the NC control mechanism 10, a circuit 6 switches the control valve (not shown) of block Z2, a circuit 7 switches the control valve (not shown) of block Y, and a circuit 9 switches the control valve (not shown) of block Y. It is possible to control and operate the block X2 in the same way, the circuit 9 in the same way in the block Xl, the circuit 11 in the same way in the block X, the circuit 12 in the same way in the block Z1. Sintering using the above apparatus is performed as follows.

The powder 18 filled in the sintering container 19 is covered with a cover plate 18S, the horizontal position is determined by drive control of the cylinders X and Y, and the cylinders Zl and Z2 are driven in the up and down z-axes to apply pressure. . Pressurizing the upper cylinder Z1 partially pressurizes the cover plate 18S from the block E3 using the tip electrode E1, and pressurizing the lower cylinder Z2 partially pressurizing the bottom of the container 19 using the electrode E2 from the block E4. The partially pressurized portion sandwiched between the upper and lower electrodes ElE2 is energized simultaneously from the upper and lower electrodes, and the pressurization is adjusted appropriately so that light contact between the powders occurs and interpowder discharge occurs. The powder is sintered by electrical discharge purification, activation, and heat treatment using electrical discharge heat and Joule heat. During sintering, the blocks E3 and E4 are driven by cylinders Xl and X2, and the contact pressure parts of the electrodes El and E2 are sequentially moved to apply partial pressure, and the sintered part is moved to perform control so that the entire sintering is performed. do. These controls are automatically performed by the NC control device 10 so that the entire powder in the container 19 is sintered. If a flexible heat-resistant material such as flexible graphite is used for the lid 18S, partial pressure will create a pressure difference in which the powder in the pressurized part that contacts the electrode E1 is dense and the powder in the other parts is sparse. This pressure difference is controlled by the movement of blocks E3 and E4, and the powder in the container can be sintered while being mixed and kneaded.
This pressurization and energization are carried out throughout the entire body, and a sintered body that is uniform and of good quality can be easily obtained. Both pressurization and energization can be configured using an extremely small cylinder power supply, and the sintering device can be made small and highly accurate, allowing large products to be easily sintered and precisely sintered over time.
Of course, the sintering operation may be performed by applying pressure with the electrodes El and E2, moving the current-carrying parts in sequence, and repeating the sintering until a predetermined density is reached.This control is performed by the NC device 10. Optionally, the best sintering possible can be controlled. The sintering container 19 may be made into a cylindrical body, and the internal powder filled therein may be pressurized from above and below and energized (7), or the opposing positions of the upper and lower electrodes El, E2 may be shifted by a required amount to press the internal powder into a meandering shape. You can also make it so that Second
The figure is an illustrative diagram of one applied embodiment.

A heat-resistant plastic film or carbon fiber cloth bag 20 is filled with sintered powder 18, a support plate 17 is placed at one end of the sealed bag, pressure is applied between electrodes E1 and E2, and E1
Electrodes E1 and E2 are energized by relatively changing the interval length a between E2 and E2, and NC control is performed if necessary to sinter the electrodes E1 and E2. The sintering is progressed by moving, changing the interval length a, and applying electricity. It goes without saying that the sintered body can be an electrically conductive one, but a non-electrical one can be mixed with conductive particles or the like, or can be made with conductivity interposed therebetween. Utilizing the ionization effect between grains caused by electricity, it can be activated, decarbonized, carbonized,
Nitriding, oxidation, reduction, etc. can also be performed in conjunction with sintering. In FIG. 3, blocks E5 and E6 are connected to electrodes El,
A guide block G7 is interposed so that E2 moves up and down relatively at the same time but does not move left and right (horizontally), and is guided by both end plates G3 and G4, and cylinder block shaft heads Z8 and Z9, Guide plates G1, G2, and G5 of the shaft head
and G6, the blocks E3 and E4 are held between the electrodes E1 and E2 to control the distance a between the electrodes E1 and E2.

In addition, in FIG. 4, the surface coating film 20 in the container 19 of the sintered powder 18 is fixed in the position of the mold ES attached to the container lower lid 2E, and both electrodes E1 and E2 are moved. is electrode E
2 moves horizontally with the electrode E1 without moving up and down, and the electrode E1 moves up and down to form the dimensions and shape of the upper surface of an arbitrary sintered body surface, and forms the dimensions and shape of the lower surface with the mold surface ES. and showed how it sintered. Further, FIG. 5 shows, as a special application example, each sintered body, Dl, Thin sintered bodies such as D2, D3, D4, and D5 are formed in advance, and these are placed in molds Al and A2.
, A3, press it up and down, apply appropriate pressure to the sintered body forming each layer, make it conform to the mold surface of the desired size and shape, and sinter weld by applying electricity. A sintered body with predetermined dimensions and size is manufactured using the following steps. The layers forming each interior of the sintered body can be chosen arbitrarily, and the final result is one with a precise surface. As already mentioned, the present invention involves adding a conductive liquid or conductive powder to the powder filled in a mold to create an internal pressure difference so as to have an appropriate internal energy density difference. By adding a suitable amount of chloride and sintering with electricity, a molded body whose crystallinity rapidly increases and becomes strong can be obtained, and its surface has a complicated size and shape.

Furthermore, energy can be used effectively and NC control can be easily applied. Moreover, a sintered body suitable for the intended use can be obtained. In addition, by applying different pressure differences locally after or during sintering, it is possible to obtain sintering with a desired density difference or uniform quality throughout the sintering. In addition, pressure is applied from each direction of the Z-axis, Y-axis, and Z-axis, and DC,
Electrical discharge, generation of Joule heat,
By using ionization, etc., it has become possible to improve energy usage efficiency.

[Brief explanation of the drawing]

FIG. 1 is a front sectional explanatory view of one embodiment of the present invention. FIG. 2 is an exemplary front cross-sectional view of the electrode section. FIG. 3 is a front sectional view of a partial application example of the electrode moving mechanism. FIG. 4 is a front sectional view of the electrode section of one application example. FIG. 5 is a front sectional view of an example of laminated sintering. S
...Power supply, 4,5...Electric circuit, X,
Y, Xl, X2, Zl, Z2...Movement mechanism, E
l, E2...Electrode, 3...Body frame, 1
0...NC unit, 6, 7, 8, 9, 11,
12...NC control circuit, 14, 15...
・Electric circuit connection part, 18... Sintered granules, 19.
... Container, 20 ... Storage membrane, bag, Gl, G2,
G3, G4, G5, G6, G7, G8...Guidance.

Claims (1)

[Claims] 1. A pressurized current-carrying electrode that presses and energizes a part of a sintered powder filled in a mold or a sintered body that has been sintered in advance. In energization sintering, the sintered powder is sintered by partially applying mechanical pressure to the sintered powder and passing a direct current, alternating current, high-frequency current, pulsed current, or a suitable combination thereof under pressure. By appropriately controlling and changing the pressure applied to the powder, the powder is partially energized and sintered, and the electrode is moved relative to the sintered powder to advance the energized sintering, thereby imparting a predetermined size and shape. A method for sintering and shaping powder and granular materials, characterized by obtaining a whole sintered body in which the sintered bodies are integrated. 2. To form the powder into a predetermined size and shape, the powder or granule to be sintered is charged into a container or flexible membrane having a mold having a surface with the predetermined size and shape, and the powder or granule is placed between opposing electrodes. The powder according to claim 1, wherein the powder is sintered as a whole or a plurality of unit sintered bodies are sintered by moving relative to each other, pressurized, and energized, and then stacked and sintered to form a single body. Method of sintering and forming granules. 3 Pressure and electricity are applied by contacting the powder to be sintered or a container made of a mold or flexible film that houses the object to be sintered, and a part of the object to be sintered stored in the container. A position showing an arbitrary integrated locus that traces a straight line along the axis center in each direction of at least two axes among the X axis, Y axis, and Z axis relative to the small area electrode and the container or electrode. A control unit that moves the electrode, a mechanical unit that mechanically applies arbitrary pressure to the object to be sintered by pressurizing the electrode, and a machine that supplies direct current, alternating current, high-frequency current, or pulse current to the object to be sintered through the electrode. unit, each of the mechanical units described above is provided on a common main body frame, connected to a common control mechanical unit, and partially sintered to obtain a sintered body having a predetermined size and shape as a whole. A device for sintering and forming powder and granular materials. 4. The mechanical units are connected and mutually compensated to operate automatically, continuously or stepwise, and an NC control unit is incorporated into the control unit to operate the energized sintered body in a predetermined manner. An apparatus for sintering and forming a powder or granular material according to claim 3 into a size and shape of . 5. The mechanism for moving the electrodes or the mechanism for moving the storage body of powder and granular material to be sintered charged between the electrodes is based on the operation of the shaft head of the hydraulic cylinder block, and the operation of each cylinder block is controlled by a control unit. An apparatus for sintering and forming a powder or granular material according to claim 3 or 4, wherein the apparatus operates independently or interlocks with each other in mutual compensation. 6. As a mechanism for moving the electrode or sintered object storage body, part or all of the fluid pressure cylinder block mechanism described in the preceding paragraph is combined with a screw attached to the pulse motor drive unit shaft and the screw attached and fixed to the device body. An apparatus for sintering and forming powder and granular material according to claim 3 or 4, wherein the parts for propelling the granular material and the shaft head are operated in conjunction with each other independently or in mutual compensation.