JPH02243703A - Method for forming powder of metal and ceramic or the like - Google Patents

Abstract

PURPOSE:To form even a product having complicate shape at high accuracy by sticking a thin film elastic material to the circumference of a wax pattern having the aimed shape, packing raw material after causing the wax in the inner part to flow out and executing cold isostatic pressing. CONSTITUTION:An original pattern 1 having an aimed shape is made of gypsum, etc., under consideration of shrinkage ratio, and half of the pattern 1 is embedded in clay 4 changed to a box made of vinyl chloride plate 3, and silicon rubber is charged and solidified on exposed part of pattern 1. Successively, this silicone rubber is used instead of the clay 4 and sticking prevention agent is sprayed on this and the silicone rubber is charged and solidified in the same way as the above. A pouring hole 6 is formed in the obtd. rubber mold 5 and molten wax is poured from this hole and solidified to obtain a wax pattern 7. The silicone rubber 11 is stick on this surface at the uniform thickness and a baggy material 20 of thin film is obtd., and after melting and causing the wax therein to flow out, the metal powder and granular raw material 18 is packed in the baggy material 20, and after closely sealing with a shut-off instrument 23, the baggy material 20 is composed with the cold isostatic pressing. By sintering this green compact, the product is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a method for molding powders of metals, ceramics, etc.

Conventional technology Conventionally, in order to mold powders such as metals and ceramics, a block-shaped molded body is created using a cold isostatic pressing method, and then this molded body is subjected to various processing before being sintered. It is known how to obtain the desired product.

Problems to be Solved by the Invention However, this method has a major drawback in that the dimensional accuracy of the molded product is poor, and it requires considerable time and manpower for processing, and furthermore, it is difficult to process the molded product. Problems were observed, such as damage such as chipping, and unnecessary use of raw materials that were cut during processing.

Therefore, the purpose of the present invention is to solve these conventional problems by using a cold isostatic pressing method using a bag-like object made of a thin film elastic material of a desired shape that corresponds to a product with a required complicated shape. It is an object of the present invention to provide a method for molding powders of metals, ceramics, etc. so as to produce a required molded body.

Means for Solving the Problems According to the method of molding powders of metals, ceramics, etc. of the present invention, a wax mold of the desired shape is created, and a thin and uniform elastic material is adhered around the wax mold to form a thin film. The method is characterized in that a bag-like object made of an elastic material is made, and after the wax inside the bag-like object is melted and flowed out, raw materials are injected and filled and molded by cold isostatic pressing.

Furthermore, according to the method of making a bag-like article of thin film elastic material used in the method of molding powders of metals, ceramics, etc. of the present invention,
A prototype of the desired shape is made of plaster or plastic, etc., a curing agent and a fast-acting agent are added to half of the prototype, and after degassing, silicone rubber is introduced and assimilated to form the mold. The method is characterized in that a wax mold is created by injecting and solidifying a wax wax into the wax mold, and a thin and uniform silicone comb is deposited around the wax mold to create a bag-like object made of a thin film elastic material.

Function: The method of molding powders of metals, ceramics, etc. of the present invention will be explained below with reference to the drawings. Figures 1 to 6 show each step in carrying out the molding method of the present invention. First, in the first stage of mold making, as shown in Fig. 1, a prototype 1 of the desired shape corresponding to the desired product is made of plaster or plastic material with the shrinkage rate calculated in advance.
The prototype 1 is placed in a box 2 made of PVC board 3 as shown in the figure, and half of it is embedded in clay 4 surrounded by PVC board 3.
Silicone rubber, which has been defoamed by adding a hardening agent and a quick-acting effect agent, is placed on top of the exposed master mold 1 and solidified. Once half of the prototype has been molded in this way, use silicone rubber that has already been molded in place of clay, apply silicone spray on it to prevent it from sticking, and place the remaining half of the prototype in the same way as before. Silicone rubber is poured into half of the exposed model to make a mold and solidify to complete the mold-making process.

An injection port 6 for a wax for lost wax is formed in a part of the rubber mold 5 thus created. The loss 1 to wax injection port 6 can also be made in advance using a rod-shaped member at the time of making the rubber mold 5 (FIG. 3). Next, a wax for lost wax that has been melted at 1.50° C. is injected from the injection port 6 of the rubber mold 5 and solidified to form a wax mold 7, thereby completing the wax mold making process.

Grip the wax inlet part 8 of the wax mold 7 thus created with a suitable grip 9, for example as shown in FIG. The silicone rubber is applied by dipping it into the wax mold 7 or by pouring it around the wax mold 7 using an object such as a spoon. In this way, the silicon comb 11 can be attached to the surface of the wax mold 7. In this state, the thickness of the silicone rubber 11 is uneven, so if you hold the wax injection port 8 of the wax mold 7 with a clip and hang it up for a while, the silicone rubber 11 will become thicker as shown in Figure 4. As shown in , the silicone rubber 11 naturally drips down and flows out, and the silicone rubber 11 is thinly and uniformly attached to the wax mold 7 .

At this time, the wax inlet part 8 of the wax mold 7 must be sealed after granules are put in it during the later molding process, so the silicone comb 1 is attached to the wax inlet part 8 up to half of the wax inlet part 8. It is preferable to leave the wax mold 7 with the injection port formed in advance.In this way, the silicone rubber 1 is placed around the wax mold 7.
1 is adhered to a thin or even thickness to create a bag-like body 10 made of a thin film elastic material.

In this way, an elastic material such as silicone rubber 11 is thinly and uniformly adhered around the wax mold 7 to create a bag-like body 10 of a thin film elastic material such as silicone rubber. When the silicone rubber 11 of the body 10 is sufficiently solidified, the body 10 is placed in an electric furnace 12 heated to about 150°C and turned upside down as shown in FIG. When placed on the support stand 12, the wax in the silicone rubber 11 of the creation body 10 will naturally melt and flow out, and after completely melting and flowing out, a bag of silicone rubber 18, which is a thin film elastic material, will be formed. 20 remains, and a pouch 20 of a thin film of elastic material is created.

In order to mold powder of metal, ceramics, etc. by cold isostatic pressing using the thin film elastic bag 20 created in this way, as shown in FIG. A raw material 18 such as alumina granules or stainless steel granules is charged into the bag-like material 20, and the preformed injection port or gate portion 22 of the bag-like material 20 is closed and sealed with a shutoff device 23 such as a wire. do. In this way, raw material 1
A bag 20 made of a thin film elastic material filled with 8 is placed in an appropriate plastic bag to prevent water from entering during cold isostatic pressing, and the inside of the plastic bag is evacuated to completely seal it. The bag 20 of the thin film elastic material sealed in the plastic bag is placed in a cold isostatic press and subjected to a predetermined molding pressure, for example 3 t/cz2 for alumina granules and 3 t/cz2 for stainless steel granules. Consolidation is performed by cold isostatic pressing at 5t/cm2. This molded body is then sintered to obtain a desired product.

Example 1 An example will be explained in which two types of raw materials were used: powder 5US304 as a metal (center particle size of raw material 8 μl) and alumina powder (center particle size of raw material 1 μl) as ceramics. .

First, a shaft with a diameter of 35111 and a length of 70zz and a diameter of 110Ox at a position of 30131 from one end of this shaft.
, a disk-shaped plastic mold with a thickness of 20'1111 was made, and this mold was made of silicone rubber (KE-
1300, manufactured by Shin-Etsu Chemical Co., Ltd.) to make a mold. After making the mold, pour wax for lost wax (manufactured by Middle East Oil Co., Ltd.) to create a wax mold, apply silicone rubber around it evenly, and after the silicone rubber has solidified, pour out the wax inside and make silicone. A thin rubber mold (thickness: 200 μ2) was created. Raw material granules are put into this silicone rubber thin mold, and the amount is 5 tons/ci2 for 5US304 and 3 tons/c for alumina.
CIP treatment was performed using m2 to obtain a compact product. When the roundness of the green compact disk of the obtained compact was measured,
There was almost no variation in dimensions, all of which were 1.0% or less. The diameter of the disk at this time was as follows.

5US304 73.25±0.121 Shoulder Alumina 70.35±0.091JIEffects of the Invention According to the method of forming powders of metals, ceramics, etc. of the present invention configured in this way, the prototype of the target shape is formed by plaster or It is made of plastic, etc., and a hardening agent and a fast-acting hardening agent are added to half of this prototype, and defoamed silicone rubber is added to solidify it, and a mold is made. Lost wax is melted from the injection port of the molded rubber mold. A wax mold is created by injecting and solidifying wax, and then pre-degassed silicone rubber is thinly and uniformly adhered around the wax mold to create a bag-like object made of thin film elastic material. After melting and draining the wax in the shaped material, the raw material is injected and filled into a bag-like material made of thin film elastic material, and this is molded by cold isostatic pressing to create a molded product. By sintering, products of any complex shape can be molded with high dimensional accuracy, and the molded body processing step can be omitted and unnecessary raw materials can be avoided.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing a master mold in the method of molding powders of metals, ceramics, etc. of the present invention, Fig. 2 is a schematic sectional view showing the state in which the mold is made using the master mold of Fig. 1, and Fig. 3 is a schematic cross-sectional view showing the state in which the mold is made. 4 is a cross-sectional view showing the rubber mold made using the rubber mold shown in FIG. FIG. 6 is a schematic diagram illustrating the process of melting and pouring out wax from a bag of elastic material, and FIG. 6 is a schematic diagram showing a process of filling the bag with required raw materials for cold isostatic pressing. In the diagram, 1: prototype, 2: box, 3
; PVC board, 4: Clay, 5: Rubber mold, 6 Inlet part, 7:
Wax mold, 8: Inlet part, 9 Nigelip, 10: Creation body, 11: Silicone rubber, 12: Electric furnace, 14: Support stand,
18: Raw material, 20 Bag-like material, 22: Gate part, 23: Shutoff device.

Claims (2)

[Claims] (1) Create a wax mold of the desired shape, adhere a thin and uniform elastic material around the wax mold to create a bag of thin film elastic material, and melt and flow out the wax inside the bag. A method for forming powders of metals, ceramics, etc., which is characterized by injecting and filling the raw materials and forming the powder by cold isostatic pressing. (2) A prototype of the desired shape is made of plaster or plastic, etc., a curing agent and a quick-acting effect agent are added to half of the prototype, and silicone rubber is poured in after defoaming, allowed to solidify, and a mold is made. A metal, characterized in that a wax for lost wax is injected and solidified from an inlet to create a wax mold, and silicone rubber is adhered thinly and uniformly around the wax mold to create a bag-like object of a thin film elastic material. A method for creating a bag-like object used in the molding method of powders such as ceramics.