JPH08225811A - Sintered compact of metal powder or ceramic powder and its production - Google Patents

Abstract

PURPOSE: To prevent a shift in position at the time of combination and joining even in the case of a small sintered compact of powder. CONSTITUTION: When plural parts are combined and joined at the time of sintering to form an integrated structure and to produce a sintered compact of metal powder or ceramic powder, plural compacts 1 of powder having an aligning part 3 besides a part made into a product part 2 are formed and combined through the aligning part 3. The combined compacts 1 are then joined by sintering. The parts except the product part 2 are separated after the combining process and before the sintering process and the objective end product part 2 is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal powder or ceramic powder sintered body which is made into an integrated structure by joining a plurality of parts at the time of sintering, and a method for producing the same.

[0002]

2. Description of the Related Art Generally, as a method for obtaining a metal powder or ceramics powder sintered body having a complicated shape, a plurality of metal powders or ceramics powder compacts are combined and joined at the time of sintering to form an integrated sintered body. The manufacturing method is well known.

The metal powder of the metal powder compact such as Fe-Ni alloy and stainless steel and the ceramic powder of the ceramic powder compact such as alumina are sintered by diffusion sintering or reaction sintering. That is, the powder compact is sintered when the powders come into contact with each other at high temperature. Therefore,
According to this method, it is not necessary to perform brazing or welding unlike the usual joining of ingots. The method for producing a sintered body described above utilizes the sintering behavior of such a powder compact, and combines a plurality of metal powders or ceramics powder compacts and sinters them to form an integral complex-shaped sintered compact. I will get it.

For example, in Japanese Unexamined Patent Publication (Kokai) No. 62-97804, a plurality of ceramic powder compacts (green bodies) are obtained by using a ceramic powder injection molding method, and the green bodies are combined and welded to each other to degrease, A method is described for obtaining an integrated final product of complex shape by performing sintering.

[0005]

However, in the above-mentioned conventional method, the alignment is performed by the component parts of the final product. Therefore, when the powder compacts to be joined are small, the joint surface will inevitably become small, and when the powder compacts are combined and joined, they are easily displaced due to the small joint surface, resulting in a final shape. However, there was a problem that it was extremely difficult to obtain.

The present invention has been made in view of the above-mentioned conventional problems, and even a fine powder sintered body is a metal powder or ceramic powder sintered body which does not cause a positional deviation when combined and joined. And a method for manufacturing the same.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 sinters a metal powder or a ceramic powder by joining a plurality of parts by sintering to form an integrated structure. In the body, a powder compact having an alignment portion other than the product portion was joined by sintering.

According to a second aspect of the present invention, in a method for producing a metal powder or ceramics powder sintered body, which is obtained by combining a plurality of parts and joining them at the time of sintering to form an integrated structure, other than a part to be a product part. A step of molding a plurality of powder compacts having an alignment part, a step of combining the plurality of powder compacts by the alignment part, a step of joining the combined powder compacts by sintering, and the alignment part And the step of obtaining a product part by separating parts other than the product part between the step of combining and the step of sintering.

The powder sintered body referred to here is formed by molding metal powder or ceramics powder, and includes metal mold molding, hydrostatic molding, hot pressing, tape molding, extrusion molding, casting molding, and metal powder. Injection molding (MIM (Metal Inje
ction Molding)), ceramic powder injection molding (CIM
(Ceramics Injection Molding)) is a general term for molded articles formed by injection molding or the like, and so-called degreased articles obtained by removing the organic binder from these molded articles.

[0010]

According to the first aspect of the invention, when the powder compacts to be joined are combined, they can be combined with high precision not by the minute product parts but by the separately provided alignment parts. According to the second aspect of the invention, when the powder compacts to be joined are combined, they can be combined with high precision not by the minute product parts but by the separately provided alignment parts. As a result, it is possible to obtain a good sintered body without causing displacement of the powder compact during sintering.

[0011]

【Example】

[Example 1] Fig. 1 is a perspective view showing a powder compact used in this example, Fig. 2 is a perspective view showing a combination of the powder compacts of Fig. 1, and Fig. 3 is a combination of powder compacts. FIG. 4 is a perspective view showing a product part, and FIG. 4 is a perspective view showing a product part only with the alignment part removed from the integrated part joined by sintering.

62 vol% SUS316L (austenitic stainless steel) powder having an average particle size of 8 μm, 18 vol% polystyrene as an organic binder, 12 vol% polyethyl acrylate, 5 vol% ethylene-vinyl acetate copolymer, 2 vol% paraffin wax, 1 vol stearic acid. % Was used to obtain a powder compact 1 (green body in this case) having a shape as shown in FIG. 1 by using a general metal powder injection molding method (MIM).

The powder compact 1 comprises a product portion 2 and an alignment portion 3. The product portion 2 is a minute semi-cylindrical shape obtained by vertically halving a pipe-shaped product having a hole with a diameter of 1 mm, a length of 3 mm, and an inner diameter of 0.5 mm. Further, the alignment portion 3 is formed into a rectangular parallelepiped projection portion 4 having a first abutment portion 6 and a second abutment portion 7, and the product portion 2 and the projection portion 4 formed continuously on the outer peripheral surface of the product portion 2. And a flat surface receiving portion 5 formed between and.

When two powder compacts 1 are prepared and they are combined, as shown in FIG. 2, the powder compacts 1 are turned upside down and the respective aligning parts 3 are combined to form the product part 2. Aligned position. That is, x
In the direction, the end faces of the second abutting portion 7 and the flat surface receiving portion 5 are combined, in the y direction, the first abutting portions 6 are brought into contact with each other, and in the z direction, the flat surface receiving portions 5 are brought into contact with each other. The two were accurately aligned. FIG. 3 shows an integrated structure of the powder compacts 1 combined by alignment.

Next, the assembled powder compact 1 is heated at a temperature rising rate of 355 ° C. under atmospheric pressure and atmospheric atmosphere to remove the organic binder in the powder compact 1 and then under vacuum atmosphere 1300. Sintered at ° C. After that, the alignment unit 3
Was removed from the product part 2 to obtain a final cylindrical product as shown in FIG.

According to this embodiment, the product portion 2 of the powder compact 1 can be accurately aligned by the separately provided alignment portion 3. That is, the end surfaces of the second abutting portion 7 and the flat surface receiving portion 5 are abutted in the x direction, the first abutting portions 6 are abutted in the y direction, and the flat surface receiving portions 5 are abutted in the z direction. The part 2 could be accurately aligned. Furthermore, during sintering, the powders in the powder compact 1 are sintered by diffusion, so that the powder compacts 1 are integrated. At this time, the product part 2 is also integrated, but the powder compact 1
Since the alignment between the products is accurate, the product part 2 is integrated accurately. Therefore, according to the present example, even a minute product was able to be obtained as a good integrated sintered body without any problem when joined at the time of sintering.

[Embodiment 2] FIGS. 5 and 6 are perspective views showing the alignment portion of the present embodiment. In this embodiment, the shape of the product part is the same as that of the first embodiment, and the description thereof is omitted. The alignment portion A21 has a groove 2 in the center.
2 is formed in a substantially U shape. On the other hand, the alignment portion B23 is formed in a substantially L shape having the protrusion 24. The product portion is aligned by fitting the groove 22 and the projection 24 together.

In this embodiment, 65 vol% of alumina (Al ₂ O ₃ ) powder having an average particle size of 5 μm and 15 v of polyethylene are used.
The product part and the alignment parts A21 and B23 were formed by injection molding using a compound (kneaded molding material) of ol%, 14 vol% of polymethamethylcrate, 4 vol% of carnauba wax, and 2 vol% of stearic acid. Here, the powder compacts are aligned with each other by the alignment portion A21.
By fitting the groove 22 and the protrusion 24 of the alignment portion B23, the product portion can be accurately aligned.

Next, the combined powder compacts were degreased and sintered. During sintering, the alumina powder in the powder compact was sintered by diffusion. As a result, the product department is integrated. Then, the alignment parts A21 and B23 were removed from the product part.

As a result, there was no displacement in the joined product parts, and a good product could be obtained. Further, according to the present embodiment, since the alignment portions A21 and B23 have different shapes, even if the product portions to be joined have different shapes, the wrong alignment portions are used to join the wrong combination. You can always join the correct ones without doing.

[Embodiment 3] FIGS. 7 and 8 are perspective views showing the alignment portion of the present embodiment. In this embodiment, the shape of the product part is the same as that of the first embodiment, and the description thereof is omitted. Average particle size of 12 μm as metal powder
SUS630 (precipitation hardening stainless steel) powder 65v
ol%, polystyrene 16vol%, ethylene-vinyl acetate copolymer 8vol%, polymethyl acrylate 5v
The product part and the alignment part were molded with a compound composed of ol%, 5 vol% of paraffin wax, and 1 vol% of stearic acid. At that time, the alignment portion A31
An alignment ring 33 was insert-molded in the. Further, the alignment taper pin 34 is provided in the alignment portion B32.
Was similarly insert-molded. This alignment ring 3
By fitting 3 and the alignment taper pin 34, the product portion can be accurately aligned. Then, after degreasing and sintering to integrate the product part, the alignment part was removed.

According to this embodiment, the alignment portion A31,
Since the product part is aligned with B32, the alignment can be performed accurately. Further, since the inserted ring and taper pin are used for the alignment, the alignment can be performed more easily and accurately.

Although the injection molding method is used in the above embodiments, the present invention is not limited to this, and any processing method for sintering a powder substance may be used.
For example, die molding, cast molding, extrusion molding, hot pressing, tape molding and the like may be used. Further, the same effect can be obtained by applying a joining aid such as carbon to the joining surface at the time of joining to make the joining stronger.

Further, in the above embodiment, after sintering and joining, the parts other than the product part were removed, but after the powder compacts were combined at the alignment part, an adhesive or the like was applied to the outside of the product part. It may be applied and fixed, and then removed except for the product part, degreased and sintered. In this case, since there are no unnecessary parts other than the product part during degreasing and sintering, a larger number of powder compacts can be put into the furnace, and there is an effect that productivity is improved.

[0025]

INDUSTRIAL APPLICABILITY As described above, according to the metal powder or ceramic powder sintered body and the method for producing the same of the present invention, when the fine metal powder or ceramic powder compact is combined and bonded, a positional deviation or the like is caused. It is possible to obtain an integrated sintered body with good accuracy and without generation.

[Brief description of drawings]

1 is a perspective view showing a powder compact used in Example 1. FIG.

FIG. 2 is a perspective view showing a combination of the powder compacts shown in FIG.

FIG. 3 is a perspective view showing a state in which the powder compacts shown in FIG. 1 are combined with each other.

FIG. 4 is a perspective view showing a final product portion obtained in Example 1.

FIG. 5 is a perspective view showing an alignment unit according to a second embodiment.

FIG. 6 is a perspective view showing a positioning unit according to a second embodiment.

FIG. 7 is a perspective view showing a positioning unit according to a third embodiment.

FIG. 8 is a perspective view showing an alignment unit according to a third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Powder compact 2 Product part 3 Positioning part 4 Projection part 5 Plane receiving part 6,7 Abutting part 21,31 Positioning part A 22 Groove 23,32 Positioning part B 24 Protrusion 33 Positioning ring 34 Positioning taper pin

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display area C04B 35/64 M

Claims (2)

[Claims] 1. A sintered body of metal powder or ceramics powder, which comprises a plurality of parts joined together by sintering to form an integrated structure, by sintering a powder compact having an alignment portion other than the product portion. A metal powder or ceramic powder sintered body characterized by being joined. 2. A method for manufacturing a metal powder or ceramics powder sintered body, which comprises combining a plurality of parts and joining them at the time of sintering to form an integrated structure, wherein a plurality of parts have an alignment part other than the product part. The step of molding the powder compact, the step of combining the plurality of powder compacts by the alignment section, the step of joining the combined powder compacts by sintering, and the step of combining by the alignment section And a step of obtaining a product part by separating parts other than the product part after the process, the method for producing a metal powder or ceramics powder sintered body.