JPH0511522B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method suitable for molding and manufacturing ceramic powder or metal/nonmetal powder into a complex-shaped, high-density sintered body having a thick wall portion. .

(Prior art) For example, isostatic pressure molding is known as a method for molding ceramic powder into a uniform and high-density molded body, but in the past, parts before being subjected to this pressure molding method were has a structure in which a rubber mold is filled with ceramic powder, so if the shape is complex, the mold will not restore uniformly after the pressure is released, and the molded object will be deformed and damaged. Since the pressure medium in the isostatic pressing method is a liquid, there are problems such as the fact that it is very difficult to handle.

(Object of the Invention) The present invention has been made to solve the above problems, and is capable of manufacturing a sintered body by molding a prototype body without using a rubber mold and using a special spherical body as a pressure medium. The purpose is to provide a method.

(Means for Solving the Problems) In the method for manufacturing a sintered body of the present invention, after a resin film is releasably attached to the upper surface of a model plate for molding a prototype body, a suction means is provided on the upper surface of the model plate. After filling the frame with spherical particles, the surfaces of the frame and the spherical particles are covered with an air-impermeable shielding film, and the frame is defined by the frame, the resin film, and the shielding film. A negative pressure is applied to the space filled with the spherical particles to solidify the spherical particles, and the frame containing the solidified spherical particles is separated from the model plate to produce a mold. The two molds produced in the above steps are combined to define a cavity, and after filling the cavity with the powder raw material for sintering, the suction negative pressure in the space is stopped, and the spherical particles are moved toward the shielding film side. The method is characterized in that the powder raw material is compressed using a pressing plate, the powder raw material is press-molded through the spherical particles and the resin film, and the press-molded compact is fired in a firing furnace.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings. First, as shown in FIG. 1, a flexible non-air permeable resin film 1 was carried using a frame-shaped holding member 3 equipped with suction means 2 onto a model plate 4 for molding a prototype. Thereafter, the resin film 1 is heated by an electric heater 5 to increase its extensibility.
Next, the surface 6 of the model board 4 is provided with ventilation holes 7 and hollow chambers 8.
and communicates with a vacuum source (not shown) via a valve 9 to create a suction action on the surface 6, and moves the holding member 3 toward the model plate 4 as shown by the two-dot chain line to remove the resin. The film 1 is adsorbed onto the surface 6 of the model board 4, and then the valve 10 is switched to release the adsorption state of the resin film 1 to the holding member 3, and the holding member 3 and the electric heater 5 are moved to the upper position of the model board 4. Remove from. Next, as shown in FIG. 2, the model plate 4 with the resin film 1 adsorbed thereon is placed on the vibrating table 11, and then the frame 12 equipped with suction means is placed on top of the model plate 4, and then , the frame 1
A spherical particulate material 13 is supplied into the container 2 from a hopper (not shown). As the spherical particles 13, slurry-like ceramics were made into spherical particles using a spray dryer, and then fired to obtain spherical ceramics having a particle size of 50 to 150 μm. The spherical particles 13 have a spherical shape and have very good fluidity. Next, the oscillator 14 attached to the vibration table 11 is driven to vibrate the model plate 4 and the frame 12, and the spherical particles 13 are filled into every corner of the frame 12. A non-breathable shielding film 15 is placed on the top surface of the object 13.
The spherical particles 13 defined by the frame 12, the resin film 1 and the shielding screen 15 are then connected to a vacuum source (not shown) through the vent hole 16, the hollow chamber 17 and the valve 18 of the frame 12. The space to be filled is brought to a negative suction pressure, and then the valve 9 is switched to release the adsorption state of the resin film 1 to the model plate 4. Thereby, the spherical particles 13 are solidified by being subjected to atmospheric pressure via the resin film 1 and the shielding film 15. The frame 12 containing the solidified spherical particles 13 is separated from the model plate 4 to obtain a mold 19. Next, a mold 39 is manufactured in the same manner as the mold 19, and these molds 19,
39 and then rotated 90 degrees to define a cavity 21 having a raw material input port 20, and then,
The powder raw material for sintering is supplied from the raw material input port 20 by the raw material supply device 22 to be filled. The powder raw material is manufactured by adding 4.5 parts by weight of wax emulsion binder (as organic solid content) and 25 parts by weight of water to 100 parts by weight of alumina ceramic powder (AL-160SG) manufactured by Showa Light Bank Co., Ltd. The ceramic slurry was made into granules using a spray dryer. Next, the cylinder 23 of the raw material supply device 22 is extended to close the raw material inlet 20 using the slide gate 24, and then the valves 18 and 38 are switched to stop the suction into the frames 12 and 32. do. Then,
The pressing plates 25, 45 are placed inside the frames 12, 32, and the shielding film 1
When the spherical particles 13, 33 are inserted from the 5, 35 side and brought close to each other and pressed, this pressing force is transmitted through the spherical particles 13, 33, and as a result, a specific weight of 0.9 g/cm ³ is created in the cavity 21. The same pressure (1000 Kg/cm ² ) is applied to the entire surface of the powdered raw material filled with the powder, and the powdered raw material is pressure-molded to increase its specific weight to 2.0 g/cm ³ . (3rd
(see figure). After the molding is completed, the press plates 25, 45 are taken out from the frames 12, 32, and then the pressed powder raw material is taken out and placed in a firing furnace to be fired.
In this case, since the powders 13 and 33 are not liquids, they are easy to handle. However, the specific weight is 3.9
A sintered body of g/cm ³ is obtained.

Note that the powder particles 13 and 33 are not limited to spherical ceramics, and may be of any material as long as they are spherical, have good fluidity, and have pressure resistance; for example, they may be spherical steel balls, that is, steel balls. .
Furthermore, the same effect can be obtained by pressure molding metal/nonmetal powder raw materials.

(Effects of the Invention) As is clear from the above explanation, in the present invention, since the mold is constructed of a resin film backed up with powder, the molded product will not be deformed or damaged after the pressure is released. Moreover, since spherical powder is used as the pressure medium, it has excellent effects such as being extremely easy to handle.

[Brief explanation of the drawing]

1 to 3 are partially sectional front views for explaining the steps of the present method invention.

Claims (1)

[Claims] 1. After a resin film is removably attached to the upper surface of a model plate for molding a prototype, a frame body equipped with a suction means is placed on the upper surface of the model plate, and the frame body is filled with spherical granules to form a rear frame. A non-breathable shielding film is placed over the surface of the body and the spherical particulate matter, and the space defined by the frame body, the resin film, and the shielding film filled with the spherical particulate matter is suctioned to a negative pressure to solidify the spherical particulate matter. The frame containing the solidified spherical particles is separated from the model plate to produce a mold, the two thus produced molds are combined to define a cavity, and the inside of the cavity is After filling the powder raw material for sintering into the space, the suction negative pressure in the space is stopped, and the spherical particles are compressed from the shielding film side by a pressing plate, and the spherical particles are compressed through the spherical particles and the resin film. A method for producing a sintered body, which comprises pressurizing a powder raw material and firing the pressurized compact in a firing furnace.