JPS6141506A - Pressure molding method of powdered body - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a powder pressure molding method for processing raw material powder mixed with a thermoplastic resin as an organic binder into a compacted solidified body.

(Prior art) Conventionally, as a method of compacting ceramic raw material powder and then machining it, an organic substance called an organic substance 2-inder is added to the raw material powder in an amount of 0.5 to 20% by weight.
After mixing and adding the mixture to a rubber bag, it is subjected to hydrostatic pressurization using a cold isostatic pressurizer to compact it, and then machined into a predetermined shape.

(Problems with the prior art) Molded bodies processed by the above-mentioned isostatic pressure are brittle due to insufficient bonding strength due to the organic binder, and so-called "edge breakage" occurs when machining minute parts. The problem is that it is difficult to process metals with precision, resulting in poor product yields.

(Object of the invention, means for solving problems) The present invention is a pressure molding method for solving the above-mentioned drawbacks in pressure molding raw material powder mixed with an organic binder. A raw material powder mixed with resin is inductively heated using high frequency waves while being hydrostatically pressurized in a high-pressure container with a built-in high-frequency electrode, and the resin is compacted into a semi-molten state, and then the resin is cooled and depressurized to be taken out from the high-pressure container. This is a powder processing method that solves the above-mentioned drawbacks by improving the bonding strength and compaction density by heating the raw material powder mixed with thermoplastic resin with isostatic pressure and high frequency induction heating. The present invention provides a pressure forming method.

(Embodiments of the Invention) FIG. 1 shows a high-pressure container used in the powder pressure molding method of the present invention, in which (1) is the high-pressure container, and the high-pressure container (lj is the high pressure, It is designed to withstand high temperatures, and is also connected to a pressure medium gas source (3) via a gas pressure amplifier (2), making it possible to perform hydrostatic pressurization using high-pressure gas. In addition, a high frequency electrode (4) is built-in, and a high frequency current is caused to flow through the high frequency electrode (4) by a high frequency generating power source (5), so that induction heating can be performed by high frequency.

The method of the present invention is to perform pressure molding using the high-pressure container (1) with a built-in high-frequency electrode. It is placed in a capsule and placed in the high-pressure container (1). Next, the high pressure container (1) is filled with high pressure gas using the pressure medium gas source (3) and the gas pressure amplifier (2) to apply hydrostatic pressure, thereby consolidating the raw material powder and applying the hydrostatic pressure. A high frequency current is passed through the high frequency electrode (4) while applying pressure to generate a high frequency wave, and the thermoplastic resin is induction heated by the high frequency wave to a semi-molten state, and then the generation of the high frequency wave is stopped and the resin is cooled and high pressure is applied. This is a pressure molding method in which the pressure of the high-pressure gas in the container (1) is lowered by an appropriate means, and the solidified product is processed into a pressure-tightly bonded body and taken out from the high-pressure container (1).

(Specific example) 95 weight percent of S z 3 N 4 powder with an average particle size of 0.7 μm and MyO powder with an average particle size of 05 μm are mixed uniformly with 5 weight percent of polystyrene powder using a ball mill to obtain a raw material powder. Next, the raw material powder was filled into a Teflon capsule container and placed in a high-pressure container (1) shown in FIG.

Nitrogen gas is used as the pressure medium, and the pressure is 1000 kg.
/cWL2 and hydrostatic processing, K, high frequency electrode (
4) A high frequency current was applied to the polystyrene to induction heat it to 200°C, and then the polystyrene was cooled and the pressure was lowered to obtain an assimilate processed product. Further, for comparison, an assimilate was obtained only by the hydrostatic pressurization without the induction heating.

Both of them become assimilated products with similar appearance, but when the bulk specific gravity of the former was measured, it was 2.30 and the latter was 2.20. By simultaneously performing induction heating using high frequency, the bond strength was improved and the compaction density was increased. It has been confirmed that the effect can be enhanced. In addition, Fig. 2 shows the rotating body (a) used in the above processing.
The scale is 5 degrees.

(Effects of the Invention) As mentioned above, according to the method of the present invention, since induction heating is performed using high frequency waves while applying hydrostatic pressure, the thermoplastic resin mixed in the raw material powder improves the bonding strength as a binder. It can be homogenized and compaction can be significantly improved, and a solidified product with excellent bonding strength, homogenization, and compaction can be obtained, and precision molding is easy and the product yield is significantly increased.

In addition, because we use induction heating using high frequency,
The above-mentioned excellent processing effect can be obtained even if the temperature is not too high, which is advantageous in terms of the durability of the pressure measuring container.

Although the present invention has been described above with reference to embodiments, it goes without saying that the present invention is not limited to such embodiments, and that various design modifications can be made without departing from the spirit of the present invention. be.

[Brief explanation of drawings]

FIG. 1 is a mechanical diagram of a high-pressure vessel used in the method of the present invention;
FIG. 2 is a side view showing the rotating body. 1: High-pressure container 2: Gas pressure amplifier 3: Gas source for pressure medium 4: High-frequency electrode 5: High-frequency generation power source Sub-agent 3 patent attorneys and non-Kaimoto important academics

Claims (1)

[Claims] A raw material powder mixed with a thermoplastic resin is heated in a high-pressure container with a built-in high-frequency electrode under hydrostatic pressure while being induction-heated using high-frequency waves to bring the resin into a semi-molten state, and then compacted.
A method for pressure molding powder, which comprises cooling, reducing the pressure, and then taking out the powder from the high-pressure container.