JP2794473B2 - Method for producing sintered member made of amorphous alloy - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention (1) Industrial application field The present invention relates to a sintered member made of an amorphous alloy, and more particularly to a sintered member made of one of an amorphous aluminum alloy and an amorphous magnesium alloy. The present invention relates to a method for manufacturing a binding member.

(2) Conventional technology In order to obtain a sound sintered member in hot extrusion, it is necessary to set the extrusion ratio high. However,
Since a high extrusion ratio cannot be obtained in one hot extrusion process due to functional limitations of an extruder or the like, a method of conventionally dividing the process into multiple stages and increasing the extrusion ratio as a result has been adopted. I have.

(3) Problems to be Solved by the Invention However, according to the multi-stage method, in each stage,
Since the material is heated at a high temperature each time, the result is advanced in the amorphous alloy material, and there is a problem that a high strength sintered member having a high volume fraction of the amorphous component cannot be obtained. .

In view of the above, the present invention provides the above-described manufacturing method capable of obtaining a sound amorphous alloy, that is, a sintered member made of an amorphous aluminum alloy or an amorphous magnesium alloy even when the extrusion ratio is set low. The purpose is to:

B. Configuration of the Invention (1) Means for Solving the Problems The method for producing a sintered member made of an amorphous alloy according to the present invention comprises a magnesium alloy or an aluminum alloy, and the amorphous powder in each powder. Volume fraction of component (V
f) 50% or more of the amorphous alloy powder, and 0.1% by volume or more of 10% by volume of a high-hardness powder showing higher hardness than the amorphous alloy powder at the plasticization temperature (Tg) of the amorphous alloy powder. % Of the raw material powder dispersed therein, and then, the green compact is heated to the plasticization temperature (Tg) or higher and lower than the crystallization temperature (Tx). It is characterized by subjecting the body to hot extrusion.

(2) Action When the above method is adopted, during hot extrusion,
The plasticized amorphous alloy powder in the compact is subjected to the compressive force of the processing machine and the crushing force of the high-hardness powder in an undeformed or slightly deformed state, so that the plasticity of the amorphous alloy powder is reduced. As the amount of deformation increases, a strong oxide film on the surface of the amorphous alloy powder is crushed. Thereby, even if the extrusion ratio is set relatively low, a sound amorphous alloy sintered member in which the amorphous alloy powders are sufficiently diffused and bonded can be obtained. Further, since the dispersion amount of the high hard powder may be a small amount necessary and sufficient to obtain the crushing action, the physical properties and chemical properties unique to the amorphous material of the sintered member are adversely affected by the mixing of the high hard powder. I do not receive.

(3) Example [Example I] Mg ₈₁ Ni ₁₂ Ce ₇ (numerical value is atomic%) was selected as a magnesium alloy, and a rapidly solidified powder was produced using a molten metal of the alloy under application of a high-pressure He gas atomizing method. did. The He gas pressure in this case was set to 100 kgf / cm ² .

The rapidly solidified powder was subjected to a classification treatment to be divided into a powder having a diameter d ≦ 22 μm and a powder having a diameter 22 μm <d ≦ 26 μm.
The powder having a diameter d ≦ 22μ has an amorphous component volume fraction (Vf) of 50% or more in each of the powders, corresponds to the amorphous alloy powder A, and has a hardness Hmv at room temperature. Is 200 to 250. On the other hand, a powder having a diameter of 22 μm <d ≦ 26 μm has a volume fraction (Vf) of the crystalline component of each powder of 50% or more, corresponds to the crystalline alloy powder B, and has a hardness Hmv at room temperature. Below 130-200.

FIG. 1 is an X-ray diffraction diagram of the amorphous alloy powder A, and a halo pattern peculiar to the amorphous material without a sharp peak can be seen.

FIG. 2 is a differential calorimetric analysis diagram of the amorphous alloy powder A.
The plasticization temperature (Tg) is 168 ° C and the crystallization temperature (Tg)
x) is 190 ° C. Therefore, the range between the plasticization temperature (Tg) or higher and the crystallization temperature (Tx) is the plasticization range, and the hot extrusion is performed in this plasticization range.

The crystalline alloy powder B has the same chemical composition as that of the amorphous alloy powder A, but has a higher crystallizing temperature (Tg) than that of the amorphous alloy powder A due to the presence of the crystal structure. Shows high hardness. Therefore, this powder B corresponds to a high hard powder.

As a raw material powder of the green compact, a mixed powder in which a crystalline alloy powder B is dispersed in an amorphous alloy powder A is used.

In producing a sintered member, a raw material powder is prepared by dispersing a crystalline alloy powder B at various ratios in an amorphous alloy powder A,
Next, a short cylindrical green compact having a diameter of 78 mm, a length of 45 mm, and a density of 95% or more was formed using the raw material powders.

Thereafter, each green compact was loaded into an aluminum alloy can body having a thickness of 10 mm and a length of 70 mm, and the above plasticizing temperature (Tg = 168 ° C.)
Heating was performed as described above, and each compact was subjected to hot extrusion under the heating.

Table I shows the hot extrusion conditions, the tensile strength of the sintered member, and the like.

As is apparent from Table I, in the production examples IV to VI using the raw material powder in which 1 to 10% by volume of the crystalline alloy powder B was dispersed in 99 to 90% by volume of the amorphous alloy powder A, the extrusion was performed. Even if the ratio, extrusion pressure, and extrusion temperature (the heating temperature of the green compact, the plasticization temperature Tg or more, and the crystallization temperature Tx) are set relatively low, extrusion processing is possible, and the volume of the amorphous component can be obtained. A high-strength sintered member having a high rate (Vf) can be obtained.

The reason why such a sintered member is obtained is that the plasticized amorphous alloy powder A in the green compact is compressed by an extruder and the crystalline alloy powder B in an undeformed or slightly deformed state. Because of the crushing force, the amorphous alloy powder A
This is because the amount of plastic deformation increases and the strong oxide film on the surface of the amorphous alloy powder A is crushed.

Production Examples I to III use the raw material powder composed of only the amorphous alloy powder A. In Production Example I, Production Examples IV to VI
When hot extrusion is performed under substantially the same conditions as those described above, extrusion can be performed, but only a sintered member having many defects such as pores can be obtained, and its strength is low.

In Production Example II, the extrusion temperature was set to be the same as in Production Examples IV to VI, and the extrusion ratio and extrusion pressure were set higher than in Production Examples IV to VI. Under these conditions, hot extrusion was performed. Can't do it. It has an extrusion temperature of 18
This is because the plastic deformability of the amorphous alloy powder A at 0 ° C. cannot follow a high extrusion ratio.

Production Example III is the same as Production Example II except that the extrusion ratio is set to the same value, the extrusion pressure is set lower, and the extrusion temperature is set higher. As the crystallization of the powder progresses, the strength of the sintered member decreases.

Production Examples VII and VIII use a raw material powder in which 26% by volume of a crystalline alloy powder B is dispersed in an amorphous alloy powder A. In Production Example VII, the extrusion ratio and the extrusion temperature were adjusted in Production Example I.
Set the same as V to VI, and set the extrusion pressure to Production Examples IV to VI.
The hot extrusion cannot be performed under such conditions. This is because the content of the crystalline alloy powder B, which is a high-hardness powder, is large, and the powder exhibits high plastic deformation resistance.

Production Example VIII is the same as Production Example VII except that the extrusion ratio is set to the same value, the extrusion pressure is set lower, and the extrusion temperature is set higher. As the crystallization of the powder A progresses, the strength of the sintered member decreases.

In view of Production Examples I to VIII, in order to obtain the crushing action of the crystalline alloy powder B, it is necessary to set the dispersion amount to 0.1% by volume or more. In order to avoid adverse effects on physical properties and the like, the crystalline alloy powder B and the dispersion amount are set to 10% by volume or less.

(Example II)

Al ₈₅ Ni ₅ Y ₁₀ (atomic%) was selected as an aluminum alloy, and a rapidly solidified powder was produced from the alloy and the molten metal by applying a high-pressure He gas atomizing method. The He gas pressure in this case was set to 100 kgf / cm ² .

The rapidly solidified powder was subjected to a classification treatment to be divided into a powder having a diameter d ≦ 22 μm and a powder having a diameter 22 μm <d ≦ 26 μm.
The powder having a diameter d ≦ 22μ has an amorphous component volume fraction (Vf) of 50% or more in each of the powders, corresponds to the amorphous alloy powder A, and has a hardness Hmv at room temperature. At 250 to 360. On the other hand, a powder having a diameter of 22 μm <d ≦ 26 μm has a volume fraction (Vf) of the crystalline component of each powder of 50% or more, corresponds to the crystalline alloy powder B, and has a hardness Hmv at room temperature. Below 180-250.

FIG. 3 is an X-ray diffraction diagram of the amorphous alloy powder A, and shows a halo pattern peculiar to the amorphous material without any sharp peak.

FIG. 4 is a differential calorimetric analysis diagram of the amorphous alloy powder A.
The plasticization temperature (Tg) is 258.8 ° C and the crystallization temperature (Tg)
x) is 287.2 ° C. Therefore, between the plasticization temperature (Tg) and below and below the crystallization temperature (Tx) is the plasticization range,
Hot extrusion is performed in this plasticizing range.

FIG. 5 is an X-ray diffraction diagram of the crystalline alloy powder B, and a steep peak indicates a crystal plane.

This crystalline alloy powder B has the same chemical composition as the amorphous alloy powder A, but due to the presence of the crystal structure, the amorphous alloy powder A has a lower plasticizing temperature (Tg) than the amorphous alloy powder A. Also show high hardness. Therefore, this powder B corresponds to a high hard powder.

As a raw material powder of the green compact, a mixed powder in which a crystalline alloy powder B is dispersed in an amorphous alloy powder A is used.

FIG. 6 is an X-ray diffraction diagram of a raw material powder in which 3% by volume of a crystalline alloy powder B is dispersed in an amorphous alloy powder A. It can be seen that the halo pattern is disturbed.

In producing a sintered member, a raw material powder is prepared by dispersing a crystalline alloy powder B at various ratios in an amorphous alloy powder A,
Next, a short cylindrical green compact having a diameter of 78 mm, a length of 45 mm, and a density of 95% or more was formed using the raw material powders.

Thereafter, each green compact was loaded into an aluminum alloy can having a thickness of 10 mm and a length of 70 mm, and the plasticizing temperature (Tg = 258.8) was obtained.
° C) or more, and each compact was subjected to hot extrusion under the heating.

Table II shows the hot extrusion air working conditions, the tensile strength of the sintered member, and the like.

As is clear from Table II, in the production examples IV to VI using the raw material powder in which 1 to 10% by volume of the crystalline alloy powder B was dispersed in 99 to 90% by volume of the amorphous alloy powder A, the extrusion was performed. Even if the ratio, extrusion pressure, and extrusion temperature (the heating temperature of the green compact, the plasticization temperature Tg or more, and the crystallization temperature Tx) are set relatively low, extrusion processing is possible, and the volume of the amorphous component can be obtained. A high-strength sintered member having a high rate (Vf) can be obtained.

The reason why such a sintered member is obtained is that the plasticized amorphous alloy powder A in the green compact is compressed by an extruder and the crystalline alloy powder B in an undeformed or slightly deformed state. Because of the crushing force, the amorphous alloy powder A
This is because the amount of plastic deformation increases and the strong oxide film on the surface of the amorphous alloy powder A is crushed.

Production Examples I to III use the raw material powder composed of only the amorphous alloy powder A. In Production Example I, Production Examples IV to VI
When hot extrusion is performed under substantially the same conditions as those described above, extrusion can be performed, but only a sintered member having many defects such as pores can be obtained, and its strength is low.

In Production Example II, the extrusion temperature was set to be the same as in Production Examples IV to VI, and the extrusion ratio and extrusion pressure were set higher than in Production Examples IV to VI. Under these conditions, hot extrusion was performed. Can't do it. It has an extrusion temperature of 28
This is because the plastic deformability of the amorphous alloy powder A at 0 ° C. cannot follow a high extrusion ratio.

Production Example III is the same as Production Example II except that the extrusion ratio is set to the same value, the extrusion pressure is set lower, and the extrusion temperature is set higher. As the crystallization of the powder progresses, the strength of the sintered member decreases.

Production Examples VII and VIII use a raw material powder in which 26% by volume of a crystalline alloy powder B is dispersed in an amorphous alloy powder A. In Production Example VII, the extrusion ratio and the extrusion temperature were adjusted in Production Example I.
Set the same as V to VI, and set the extrusion pressure to Production Examples IV to VI.
The hot extrusion cannot be performed under such conditions. This is because the content of the crystalline alloy powder B, which is a high-hardness powder, is large, and the powder exhibits high plastic deformation resistance.

Production Example VIII is the same as Production Example VII except that the extrusion ratio is set to the same value, the extrusion pressure is set lower, and the extrusion temperature is set higher. As the crystallization of the powder A progresses, the strength of the sintered member decreases.

In view of Production Examples I to VIII, in order to obtain the crushing action of the crystalline alloy powder B, its content needs to be set to 0.1% by volume or more. In order to avoid adverse effects on physical properties and the like, the dispersion amount of the crystalline alloy powder B is set to 10% by volume or less.

FIG. 7 is a photomicrograph (× 400) showing the metal structure of the green compact (Al ₈₅ Ni ₅ Y ₁₀ ). The green compact is composed of amorphous alloy powder A and 3% by volume of crystalline alloy powder B. Molded using a raw material powder (see FIG. 6) in which is dispersed. In FIG. 7, the light gray powder is the amorphous alloy powder A,
The dark gray powder is crystalline alloy powder B.

In preparing the raw material powder in Examples I and II,
When classifying the rapidly solidified powder, the cut point is set to, for example, a value larger than the diameter of 22 μm in the above-described example, and after the classification, the amorphous alloy powder having a diameter of 22 μm or less, It is also possible to include a small amount of crystalline alloy powder having a larger diameter.

In addition, as the high hard powder in the present invention, besides the crystalline alloy powder B, a crystalline alloy powder having another chemical component, a ceramic powder, or the like can be used.

C. Effects of the Invention According to the present invention, using the raw material powder specified as described above, and by applying hot extrusion, even if the extrusion ratio is set low, a sound amorphous alloy, that is, It is possible to provide the above-mentioned manufacturing method capable of obtaining a sintered member made of an amorphous aluminum alloy or an amorphous magnesium alloy. In addition, since the dispersion amount of the high-hardness powder is small, the powder does not impair the properties unique to the amorphous property of the sintered member.

[Brief description of the drawings]

FIG. 1 is an X-ray diffraction diagram of a magnesium alloy powder which is an amorphous alloy powder, FIG. 2 is a differential calorimetric analysis diagram of the amorphous alloy powder, and FIG. 3 is a diagram of an aluminum alloy which is an amorphous alloy powder. X-ray diffraction diagram, FIG. 4 is a differential calorimetric diagram of the amorphous alloy powder, FIG. 5 is an X-ray diffraction diagram of the crystalline alloy powder, and FIG. FIG. 7 is an X-ray diffraction diagram of the added raw material powder, and FIG. 7 is a micrograph showing a metal structure of a green compact using the raw material powder of FIG. A: amorphous alloy powder, B: crystalline alloy powder (high hard powder)

Claims (3)

(57) [Claims] An amorphous alloy powder comprising a magnesium alloy and having an amorphous component volume fraction (Vf) of 50% or more in each powder is added to an amorphous alloy powder having a plasticizing temperature (Vf). Tg)
Forming a green compact using the raw material powder dispersed in 0.1% by volume or more and 10% by volume or less, and then heating the green compact to the plasticization temperature (Tg) or higher and lower than the crystallization temperature (Tx), A method for producing a sintered member made of an amorphous alloy, comprising subjecting the green compact to hot extrusion under the heating. 2. An amorphous alloy powder made of an aluminum alloy and having a volume fraction (Vf) of an amorphous component in each powder of 50% or more, and a plasticizing temperature of the amorphous alloy powder (Vf). Tg)
Forming a green compact using the raw material powder dispersed in 0.1% by volume or more and 10% by volume or less, and then heating the green compact to the plasticization temperature (Tg) or higher and lower than the crystallization temperature (Tx), A method for producing a sintered member made of an amorphous alloy, comprising subjecting the green compact to hot extrusion under the heating. 3. The method according to claim 1, wherein the high-hardness powder has the same chemical composition as the amorphous alloy powder, and a volume fraction (Vf) of a crystalline component in each powder is 50% or more. ) Or the method for producing an amorphous alloy sintered member according to item (2).