JPH02115301A - Manufacture of metal sintered body - Google Patents

Abstract

PURPOSE:To manufacture a metal sintered body without developing any deformation and breakage by mixing fibrous metal with mixed body of metal powder and organic binder, kneading, compacting and sintering after removing the binder. CONSTITUTION:The metal powder having alloy of Fe 55% - Ni 45%, etc., and about 10mum average particle diameter, the fibrous metal having the alloy of the same composition as the above, about 10-20mum diameter and about 2-5mm length and the organic binder are mixed. Mixing ratio thereof is made to for example about 76wt.% the metal powder, about 15% the fibrous metal and about 9% the organic binder. After kneading this mixed material, a green compact is obtd. with extrusion-molding or injection-molding. The binder in this green compact is removed to obtain a brown compact. After that, this brown compact is sintered to obtain the metal sintered body. By blending the above fibrous metal, strength of the green compact and the brown compact is improved and the development of the deformation and damage thereof is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a metal composition, and particularly to a method for manufacturing a metal green compact that is less deformed after depine removal.

[Prior Art] An example of a conventional method for manufacturing a metal composition is a method performed by sintering a green compact. That is,
A method is used in which a green compact of metal powder is produced by compressing metal powder by pressurizing it from above and below with a mold punch, and then sintering the green compact as described above to obtain a desired metal composition. It's here.

Therefore, the shape of the powder compact when producing the powder compact by the above-mentioned procedure is limited to relatively simple shapes such as cylinders and cylinders, and to obtain products with more complex shapes, sintering is required. It is necessary to perform post-processing such as cutting and grinding on the finished product.

On the other hand, in the field of ceramic products centered on so-called engineering ceramics, the raw material powder is
Industrially, it is possible to add a certain amount of organic binder, mix, knead, and then injection mold or extrude to obtain a green molded product with a complex shape, and then turn it into a sintered product through a depinemation process and a sintering process. It is beginning to be practiced and is attracting attention.

In addition, there have been remarkable developments in metal powder manufacturing technology in recent years, as typified by the atomization method, and it is now possible to apply the aforementioned manufacturing method using injection molding or extrusion molding to metals. became.

Injection molding and extrusion molding methods have traditionally been applied to shaping plastic materials, but because they have the characteristic of being able to mass-produce complex shapes with high precision, It has the potential to provide the market with metal sintered bodies in shapes that were not possible with conventional technology at low cost.

Here, it is important to produce a metal green compact using the above-mentioned production method. The goal is to establish a method for obtaining metal compositions.

[Problems to be Solved by the Invention] The above-mentioned conventional method for producing a metal green compact involves adding a large amount of organic binder to the powder, and plastic processing using injection molding or extrusion to obtain a green body. The organic binder is removed during the pine mite process to create a so-called brown body, but since the organic binder, which is the binder between the powders of the green molded body, is not dependent on the brown body, the pine mite removal process takes a few minutes, and it is removed in the subsequent process. It has the disadvantage of forming a capsule or breaking during transportation to a certain sintering process or during storage.

To address this drawback, attempts have been made to leave a small amount of organic binder in the Brown's body at the end of the de-binding process to give strength to the Brown's body. Not only is it difficult to control the conditions, but the remaining organic binder decomposes and vaporizes in the next sintering process, contaminating the sintering atmosphere, which is a new problem. It's not.

A technical object of the present invention is to provide a method for producing a metal powder compact whose Brown body is relatively strong and which does not pollute the sintering atmosphere during formation of the sintered compact.

[Means for Solving the Problems] In order to eliminate the above-mentioned drawbacks, the present invention provides a method for mixing and kneading a binder mainly composed of a thermoplastic resin with a mixture of fibrous metal and ordinary metal powder. , plastic processing into desired shape using injection molding method or extrusion method,
This is a manufacturing method in which a metal composition is obtained through a sintering process.

According to the present invention, in the method for producing a metal compact by kneading a mixture of metal powder and an organic binder, press-molding, and removing the binder, a fibrous metal is mixed in the mixture. A method for producing a metal green compact characterized by the following is obtained.

In the method for producing a metal compact of the present invention, pressure molding refers to a molding method performed while applying pressure, such as extrusion molding and injection molding.

That is, the present inventors focused on the fact that the bonding between powders is performed only by the binder, and by replacing a part of the powder with fibrous metal, the fibrous metal becomes entangled inside the green molded body, It has been found that the brown body has high strength even after the binder is removed by a depine removal process.

[Example] Next, embodiments of the present invention will be described in detail.

An alloy having a composition of Fe 55wt96-Ni 45vt% was melted by high frequency heating in an argon gas atmosphere, and a powder with an average particle size of 10 μm was produced by water atomization.

Next, the alloy of 55 vt% Fe-45 vt% Ni was rotated and made into short fibers by a so-called crack vibration method in which a vibrating tool was intermittently pressed against the alloy to produce a fibrous alloy with a diameter of 10 to 20 μm and a length of 2 to 5 II 1 m.

Next, the aforementioned Fe-Ni alloy powder and fibrous alloy were mixed and kneaded according to the composition shown in Table 1 to obtain a raw material for injection molding.

Next, the above-mentioned raw material for injection molding was processed using a screw injection molding machine at a cylinder temperature of 190°C and a gauge pressure of 100 kg/a.
A green body with an outer diameter of 50 m, a thickness of 1 mm, 2 mm, 5 fins, and 101111 mm was molded under the conditions of m2.

Furthermore, the above-mentioned green molded body was heated with argon gas at 2fI/
The mixture was heated from room temperature to 600° C. at a temperature increase rate of 10° C. per hour in a sin-flowing atmosphere, held at 600° C. for 2 hours, and then cooled to room temperature to obtain a boulane compound.

For comparison, injection molding raw materials obtained by mixing and kneading according to the composition shown in Table 1 without adding Fe-Ni fibrous alloy were used, and the other steps were the same as in the previous example. I got a brown body.

Table 2 shows the bending strength of the above Brown bodies.

As is clear from Table 2, according to the present invention, a brown body with high strength can be provided under the same molding conditions and the same binder conditions.

It can be seen that a metal sintered body can be easily obtained by sintering this Brown body.

Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the present invention.

For example, the alloy composition is Fe55νt%-Ni45vt
Although 96 alloy was used, there is no problem in using not only the Fe-Ni ratio but also other metals and alloys, such as pure iron and stainless steel.

Furthermore, it goes without saying that the composition of the binder is not limited to the above-mentioned composition, and for example, polystyrene, polyethylene, acrylic resin, etc. can be used.

[Effects of the Invention] As explained above, in the method for manufacturing a metal compact of the present invention, a binder is added to a mixture of fibrous metal and metal powder and plastic working is performed, so that the fibrous metal is not entangled inside the green body. This has the effect of improving the strength of the buran body after the depine removal process, and it is possible to provide a method for producing a metal green compact that can prevent deformation or destruction during transfer to the sintering process or during storage.

Procedural amendment (voluntary) Showa J? 2019/February, 2P day

Claims (1)

[Claims] 1. A method for producing a metal green compact by kneading a mixture of metal powder and an organic binder, press-molding it, and removing the binder, characterized in that a fibrous metal is mixed into the mixture. A method for producing a metal green compact.