JPS5836641B2 - Method for manufacturing powder sintered articles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves forming metal or alloy powder into a molded body using thermosetting plastic as a binder, heat-treating it (primary firing) to bring it into an incompletely polymerized and hardened state, and then press punching. The present invention relates to a press punched and machined powder sintered body article that can obtain an article of good hardness by performing a complete hardening treatment (secondary firing) after the process.

The object of the present invention is to facilitate the press punching of powder molded articles and at the same time to produce articles that have a strength comparable to that of conventional products.

Another object of the invention is to produce powder molded articles of smaller size and complex shapes.

In recent years, powder molded products have been used for a wide variety of purposes, and conventional simple shapes and manufacturing methods are no longer sufficient.

FIGS. 1 and 2 (showing the manufacturing process of a conventional powder sintered article) will be described below.

The molding powder 1 is generally a powder of magnet, stainless steel, aluminum, etc., and the numeral 2 is a binder mainly used for epoxy, rubber, or other adhesives.

A method has been considered in which these are kneaded and molded (3) to produce a precept-shaped product (4), which is then burned (5) and the resulting block is press-pulled (6) to produce a complete precept (7), but the block is hard and Because it is brittle, it breaks during press punching, resulting in a large number of cracks, making it difficult to mass-produce it.

Therefore, conventionally, as shown in Figure 2,! Form 3 into the shape of the completed product 7 from the seriousness, fire 5 the precept-shaped product 4, and make the completed product 7.
I have taken the method of obtaining .

However, this conventional method has the following drawbacks.

1. It is not suitable for mass production because it must be molded individually.

2. Only simple shapes can be formed.

3. It is difficult to manufacture extremely small parts.

4. There are dimensional changes due to firing, making it difficult to apply to precision parts.

As a result, the range of use of conventional powder molded products has been greatly restricted, and there has been a demand for a solution to these drawbacks.

The present invention was developed in view of this situation, and the relationship between the firing temperature, hardness, and elasticity when polymerizing and curing a molded product mixed with a plastic binder is as shown in Figure 3. For this reason, the firing process is divided into two, and the first firing is performed at a low temperature to create a flexible plate-like block, which improves the press punching process of powder or shaped products. This is a method for producing a powder sintered article that imparts good hardness by performing secondary firing at an appropriate degree of immersion after processing.

Hereinafter, the present invention will be explained in detail with reference to Examples.

Example 1 Figure 4 shows a rare earth monocobalt permanent magnet (SmC) of the present invention.
This is an example of powdered form of O 5 ).

Items and steps that are the same as the conventional powder compacting process of FIGS. 1 and 2 are designated with the same reference numerals.

5' is primary low temperature firing. This embodiment will be explained with reference to FIG.

1 was a rare earth monocobalt magnet powder, and 2 was an epoxy adhesive used as a binder.

3 is molding, and a plate with a length of 24 TL, 1 IL, and a width of 15 m and a thickness of 0.5 plate was produced.

4 is the completed molding. 5' is about 2
, 5H primary firing.

As a result, a very flexible powder or shaped product was obtained which had mechanical properties of transverse rupture hardness of 4 kg/mA1 and elasticity (strain) of 0.25 mm.

This material can be press punched. In this example, as shown in 6, from this plate, a diameter of 3 mm and a hole diameter] mrn
20 products were press-cut and then fired 5 for 1 hour at 150'C, which is the optimum temperature for polymerization of this epoxy resin.

As a result, transverse rupture hardness IO kg/mV1 elasticity (strain) O. A good product 7 with mechanical properties of 14 mm was obtained.

In addition, when the block was completely fired at 150'C from the beginning and was punched out, the block was cracked and the product had cracks and cracks, and 90 pieces or more were defective.

Example 2 Using the same method as in Example 1, a diameter of 1 and a hole diameter of 0. 4 1r
Lm, thickness 0. A 5 mm product was created.

Approximately 150 items were obtained from a board measuring 24 vertically by 15 horizontally and 0.5 mm thick.

In addition, when a block that had been completely fired at 150°C from the beginning was punched out, the plate cracked and the work could not be performed.

In this example, a permanent magnet powder molded product is shown, but it is also effective for molded products made of other powders.

Further, the shape is not limited to a cylinder, but also applies to other geometric shapes.

Since the method for manufacturing a powder sintered article of the present invention has the structure and operation as described above, it can obtain the following effects.

(1) Using two-stage firing, press punching of powder molded products has become easier, and it has become possible to manufacture products that have the same strength as the original material.

(2) Because press punching has become easier, it has become possible to mass-produce products with complex shapes.

(3) It is now possible to easily produce items with minute dimensions and complex shapes, which were previously difficult.

(4) The effect of dimensional changes due to firing is reduced because the fired product is press punched and fired again.

[Brief explanation of drawings]

FIG. 1 shows a conventional manufacturing process including press punching of a powder sintered article. FIG. 2 shows a conventional manufacturing process of a powder sintered article without press punching. FIG. 3 is a graph showing the relationship between firing temperature, hardness, and elasticity during polymerization and hardening. FIG. 4 shows the manufacturing process of the powder sintered article of the present invention. 1...Powder, 2...Binder, 3.
・・・・・・Certain process, 4．・・・Prepared product, 5・
...Firing, 5'...First firing, 6...
...Press punching process, 7...Finished product.

Claims (1)

[Scope of Claims] 1. In a method for manufacturing an article in which metal or alloy powder is formed into a molded body using a thermosetting plastic as a binder, and the plastic binder undergoes incomplete polymerization by performing mechanical processing such as press punching. Perform primary firing under heat treatment conditions that will result in a hardened state, press punching and machining to produce an article of the desired shape, and then perform a complete hardening process (secondary firing)6. A method for producing a powdered sintered article, characterized in that the powder is a rare earth-cobalt compound, the plastic binder is an epoxy resin, and the primary firing degree is 50 to 1.
00'C1 The method for manufacturing a powder sintered magnet body according to claim 1, wherein the secondary sintering temperature is 100 to 200'C.