JPH0657304A - Production of billet made of powder alloy - Google Patents

Abstract

PURPOSE:To provide the process for production of the billet made of powder alloy to be used for plastic working of a powder alloy. CONSTITUTION:This process for production of the billet made of the powder alloy consists in successively and densely packing a easily plastically workable powder alloy 2, then packing a hardly plastically workable powder alloy 3 into a can 1 and degassing the powder alloy after hermetic sealing. A symbol 2 is coarse powder and 3 is fine powder. The powder alloy is quenched and solidified alloy powder of an Al base, Mg base, Ni base, Ti base, Fe base, etc. As a result, even the rapidly cooled and solidified alloy powder which is hardly plastically workable is easily worked and in addition, the initial working pressure can be suppressed and, therefore, the plastically worked member having excellent mechanical characteristics, such as high strength and high hardness, is obtd. with lessened heat generation by working and without degrading the properties of the powder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a method for producing a powder alloy billet used for plastic working of a powder alloy.

[0002]

2. Description of the Related Art Conventionally, in order to produce a plastically worked molded product from a powder alloy, a powder alloy is filled in a can of a predetermined size, uniformly compacted, and degassed to form a billet, which is used as needed. It was heated by heating and subjected to plastic working such as extrusion, forging, and rolling to make a molded product.

[0003]

In the above-mentioned conventional technique, for example, the extrusion process will be described. In the initial stage of the extrusion process, the extrusion pressure becomes maximum, but when the extruded material starts to be extruded, the extrusion pressure drops. In the case of easily extrudable powder, the billet prepared by the conventional method was sufficient, but in the case of billet using hard extrudable powder such as rapidly solidified powder for high quality such as high strength and hardness. However, the extrusion pressure in the initial stage of extrusion was abnormally high, and there was a limit to the processing with ordinary plastic working machines (extruders) and dies. Also, in order to facilitate plastic working, when the working temperature is raised, the physical properties of the rapidly solidified powder change,
There is a problem that mechanical properties such as strength and hardness are deteriorated. Further, the powder is generally produced by an atomizing method,
The powder particles are not uniform, and the powder particles are classified by a classifier and divided into coarse powder and fine powder.The fine powder is used for high quality, but the coarse powder is used for low quality or in some cases as waste. Was becoming.

According to the present invention, by changing the powder to be packed in a can, it is possible to easily perform plastic working while maintaining the characteristics of the powder, and to make effective use of all manufactured powder alloys. is there.

[0005]

The present invention is characterized in that a can is successively and densely filled with a powder alloy having an easily plastic workability and then a powder alloy having a poor plasticity workability, followed by degassing after sealing. This is a method for manufacturing a powder alloy billet.

The alloy powder to which the present invention is applied includes Al
There is a rapidly solidified alloy powder made of any one of a base, a Mg base, a Ni base, a Ti base, and a Fe base, or a combination thereof, but it is not limited only to these. A relatively coarse powder is used as a powder alloy with easy plastic workability,
A relatively fine powder is used as the powder alloy that is hard to plastically work. To that extent, coarse powder is used if the average particle size is greater than 100 μm, and fine powder is used if it is smaller than 100 μm, more preferably 80 μm or less, and even more preferably 50 μm or less.

1 to 4 are typical examples of the form of filling coarse and fine powders into a can. FIG. 1 can also be said to be a two-stage type, in which the bottom lid of the can 1 is filled with coarse powder 2, then fine powder 3 and a lid 4.

FIG. 2 can also be said to be an inclined type, in which the bottom cover of the can 1 is filled with coarse powder 2 and then a mixed layer of fine powder 3 is sequentially packed so that the amount of fine powder 3 increases in an inclined manner. It is made by 4.

FIG. 3 can also be said to be an inclined type deformation, in which the two parts of the coarse powder are valley-shaped and the fine powder 3 parts are mountain-shaped so that both cans 1 are formed.
It is the one with the lid 4 closed.

FIG. 4 shows a case 1 in which coarse powder 2 is packed along the inner wall surface of the can 1, fine powder 3 is packed in the center, and a lid 4 is provided. This type is particularly suitable for forging and rolling.

[0011]

According to such a method, the working pressure at the initial stage of plastic working can be reduced, and the plastic working can be easily carried out by using an ordinary plastic working machine or die.

[0012]

EXAMPLES Next, the present invention will be specifically described with reference to Examples and Comparative Examples.

6063 with a diameter of 41 mm and a length of 120 mm
The alloy can was filled with 120 mm of rapidly solidified fine crystal fine powder (average particle size 40 μm, referred to as B alloy powder) made of Al-Ni-Mm that was hard to plastically work to form a billet a. Next, an easily plastically workable 6063 alloy (average particle size 100
.mu.m, referred to as "A alloy powder") for 20 mm, and the B alloy powder and the A alloy powder are gradually reduced in the compounding amount of the A alloy powder to obtain a mixed powder of 20 mm, and the B alloy powder is further packed for 80 mm to form a billet b.

Degas both billets a and b at 400 ° C.,
After pressing to a pressed density of 98%, heat to 360 ° C,
It was extruded at an extrusion ratio of 15.

Next, in the production of the billet b, A
Instead of alloy powder, Al-N is used as a powder with easy plastic workability.
Rapidly solidified fine crystal coarse powder material composed of i-Mm (average particle size 1
00 μm, referred to as C alloy powder), the first C alloy powder to replace the A alloy powder is 10 mm, the gradient layer of C and B alloy powder is 100 mm, and the B alloy powder is 10 mm to form a billet c. Was extruded under the same conditions as above.

Further, as the D alloy powder of the hard-to-plastic workability alloy powder, a rapidly solidified fine crystal fine powder (average particle diameter 40 μm) of Al—Ni—Mm—Zr was used, and the tip of the can material similar to the above was 20 mm. 3 was filled with A alloy powder, and then the D alloy powder was filled so that the angle of the chevron in FIG.

Further, a can was filled with only D alloy powder to form a billet e.

The billets d and e were extruded in the same manner as the billets a, b and c described above. In the case of billet e, extrusion could not be performed due to poor plastic workability. Table 1 shows the test results for the other billets a, b, c, and d.

[0019]

[Table 1]

The relationship between the extrusion time and the extrusion pressure in the above test is shown in FIG. It can be seen that the initial extrusion pressure is significantly reduced in the case of the present invention.

[0021]

According to the method of the present invention, it is possible to easily process even the rapidly solidified alloy fine powder, which is difficult to plastically process.
Also, since the initial processing pressure can be suppressed, the processing heat generation is small, and the physical properties of the powder are not deteriorated. Therefore, a plastically processed member with superior mechanical properties such as higher strength and higher hardness than powder alloys can be obtained. Obtainable. When the extruded member is used, a member whose characteristics change in an inclined manner can be obtained, so that a material for a new application can be obtained. Further, when a metal powder is produced by rapid solidification, coarse powder and fine powder are inevitably produced, but the utility value of the coarse powder discarded as low quality is industrially advantageous.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of another embodiment of the present invention.

FIG. 3 is an explanatory diagram of another embodiment of the present invention.

FIG. 4 is an explanatory diagram of another embodiment of the present invention.

FIG. 5 is a graph showing the relationship between extrusion time and extrusion pressure in the present invention and comparative examples.

[Explanation of symbols]

 1 can 2 coarse powder 3 fine powder 4 lid

Claims (5)

[Claims] 1. A method for producing a powder alloy billet, characterized in that a can is successively and closely filled with an easily plastic workable powder alloy and then with a hard plastic workability powder alloy, and the gas is sealed and then degassed. 2. The method for producing a powder alloy billet according to claim 1, wherein the easily plastic workable powder alloy is coarse powder and the hardly plastic workable powder alloy is fine powder. 3. The powder alloy is Al-based, Mg-based, Ni-based, T-based.
The method for producing a powder alloy billet according to claim 1 or 2, which is a rapidly solidified powder alloy of any one of i group and Fe group or a combination thereof. 4. The method according to any one of claims 1 to 3, wherein the amounts of both powder alloys are mixed in an inclined manner at the boundary between the easily plastic workable powder alloy and the hard plastic workable powder alloy. Of the powder alloy billet of. 5. Heating after or during degassing,
The method for producing a powder alloy billet according to any one of claims 1 to 4, which comprises compacting.