JPH07278714A - Aluminum powder alloy and its production - Google Patents

Abstract

PURPOSE:To produce an Al powder allay in which rapidly solidified Al alloy powder is rigidly combined with each other by imparting heat history as small as possible and excellent rapid solidifying properties are maintained and to provide a method for producing the same. CONSTITUTION:This Al powder allay has a compsn. contg., by weight, 0.3 to 1.5% Mg and 0.3 to 1.5% Sn, in which the containing ratio (Mg/Sn) of wt.% of Mg to the wt.% of Sn is regulated to 0.8 to 1.25, and the balance substantial Al with inevitable impurities. Thus, the aluminum powder alloy excellent in hot forgeability can be obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum powder alloy and a method for producing the same, and more particularly to a heat resistant and wear resistant aluminum powder alloy having excellent hot forgeability and a method for producing the same. is there.

[0002]

2. Description of the Related Art In the powder metallurgy method, a rapid solidification method is used to obtain Si.
Even if a large amount of transition metal alloy elements such as (silicon), Fe (iron) and Ni (nickel) is added, it is possible to obtain a dispersion strengthened aluminum alloy powder having a fine and uniform structure. In particular, in this case, it is known that by increasing the rapid solidification rate, the structure of the powder becomes finer and excellent properties can be obtained.

The rapidly solidified Al (aluminum) powder alloy is produced by solidifying the powder obtained by such rapid solidification. However, the surface of the powder is covered with a hard aluminum oxide film, which hinders the binding between the powders. Therefore, in order to firmly bond the powders to each other, the aluminum oxide film on the surface of the powder should be destroyed.
Need to be removed. As a method therefor, a method of mechanically destroying and removing the oxide film and a method of chemically dividing and removing the oxide film can be considered.

The first mechanical destruction method is to heat the powder to soften the powder to the extent that it can be plastically deformed, and then subject the powder to plastic working to destroy the surface oxide film and bond the powders together. There is a method of solidifying. This solidification method includes a hot extrusion method and a hot forging method.

In the hot extrusion method, it is necessary to extrude the powder compact at a sufficiently large extrusion ratio in order to give sufficient plastic deformation to divide / break the oxide film to obtain a strong bond between the powders. is there. The extrusion ratio here is the ratio of the cross-sectional area of the powder compact to the cross-sectional area of the extruded material. Therefore, if the extrusion ratio is increased without changing the dimensions of the extruded material, the dimensions of the powder compact must be increased. When the powder compact becomes large, it becomes difficult to uniformly raise the temperature inside the powder compact, and the preheating time before extrusion must be extended. However, when heated at such a high temperature for a long time, the fine structure obtained by the rapid solidification method is decomposed by the diffusion of alloying elements and gradually coarsened. For this reason, there is a problem that the characteristics due to rapid solidification deteriorate, and an Al powder alloy having excellent performance has not always been realized by this hot extrusion method.

On the other hand, in the hot forging method, it is necessary to plastically deform the powder particles by heating and compression to bond the powder particles together without giving a large plastic flow. For this purpose, it is necessary to heat the powder particles to a sufficiently high temperature, otherwise the powder particles do not bond sufficiently, so cracks occur at the powder grain boundaries, and sufficient solidification cannot be achieved.

Even in the case of the hot forging method, it is necessary to heat at a high temperature. Therefore, similar to the above, there arises a problem that the fine structure obtained by the rapid solidification is decomposed by the diffusion of the alloying element and gradually coarsened to deteriorate the properties due to the rapid solidification.

Further, as a method of manufacturing an Al powder alloy member, there is a technique proposed in, for example, Japanese Patent Laid-Open No. 63-60265. In this technique, the powder compact is heat-treated in the air atmosphere for the purpose of removing the water adsorbed on the surface of the powder particle. However, in this technique, the water once removed reacts with aluminum again to form a strong aluminum oxide film on the powder surface, thereby preventing the powder particles from binding to each other. In addition, after heat treating the powder compact in order to sufficiently break the oxide film existing on the powder surface and bond the powders together, a total of two hot forgings are carried out through preliminary hot closed die forging. To be done. Therefore, this technique also has an economical problem in the manufacturing process.

On the other hand, regarding the chemical dividing method,
As an invention based on an idea similar to this method, for example, "joining method of Al or Al alloy sintered member" in JP-A-59-64158, JP-A-59-110482 and JP-A-59-110483. The "joining method for Al-based sintered members" in Japanese Patent Publication has been proposed.

In the techniques proposed in these publications, when joining an Al alloy or an Al-based sintered body, Cu (copper), Sn (tin), Zn (zinc), Mg
This is a technique of adding 1 to 50% by weight of elements such as (magnesium) and Si. In other words, this technique involves adding additives such as Cu to the joint, or inserting those elements into the joint in the form of powder or green compact, and then heating (sintering) the joint. A eutectic or a part of liquid phase is generated, and due to the progress of mutual diffusion phenomenon based on this, Al
This is a method of firmly joining an alloy or an Al-based sintered body.

However, in this method, the heating (sintering) temperature is relatively high at about 520 to 630 ° C., and it is necessary to perform heating for about 30 to 60 minutes for a long time. Therefore, when using an Al alloy powder having a rapidly solidified structure,
The fine rapidly solidified structure becomes coarse and the originally excellent performance of the rapidly solidified structure is reduced or disappears. Also, it requires heating and pressurization at high temperature for a long time,
Depending on the alloy composition to be contained, it is necessary to interpose a joining layer at the joining portion, and there is a problem in terms of economy.

[0012] Therefore, an object of the present invention is to provide an Al powder alloy in which rapidly quenched Al alloy powders are firmly bonded to each other and excellent rapid solidification characteristics are maintained, and a method for producing the same.

[0013]

As a result of various experiments and studies, the present inventors have found that Mg is 0.3 wt% or more and 1.5 wt% or less, and Sn is 0.3 wt% or more. 5% by weight or less and M based on Sn% by weight
It has been found that an Al powder alloy having a weight% content of g of 0.8 or more and 1.25 or less has excellent strength and elongation.

Therefore, in the Al powder alloy of the present invention, M
g is 0.3% by weight or more and 1.5% by weight or less, Sn is 0.3
The content ratio of Mg wt% to Sn wt% is 0.8 to 1.
It is 25 or less, and the balance is substantially Al and unavoidable impurities.

In the Al powder alloy according to a preferred aspect of the present invention, Fe is 2.0% by weight or more and 7.5% by weight or less,
Ni is contained in an amount of 2.0% by weight or more and 7.5% by weight or less,
Further, the content ratio of the weight% of Fe to the weight% of Ni is 0.8 or more and 1.25 or less.

Al powder according to another preferred aspect of the present invention
In the alloy, part of Al is Al₉ FeNi metal
It is contained in the Al powder alloy as an intermetallic compound. Also,
Al ₉ FeNi intermetallic compound is 0.2 μm or more
Having a particle size of 3.0 μm or less and in an Al matrix
Are evenly dispersed in.

A according to yet another preferred aspect of the present invention A
The l powder alloy has a tensile strength of 40 kgf / mm ² or more at a temperature of 150 ° C. or more and 200 ° C. or less.

A according to yet another preferred aspect of the present invention
The 1 powder alloy contains Si in an amount of 5% by weight or more and 40% by weight or less.

A according to yet another preferred aspect of the present invention A
In the l powder alloy, the Si crystal grains have a grain size of 10 μm or less.

A according to yet another preferred aspect of the present invention
1 powder alloy contains Cu in an amount of 1.0% by weight or more and 4.0% by weight
Hereinafter, Mn is contained in an amount of 0.2% by weight or more and 1.0% by weight or less.

As a result of various experiments and investigations, the inventors of the present invention held the rapidly solidified Al alloy powder and its powder compact at a temperature of 400 ° C. or higher and 520 ° C. or lower for 10 seconds or longer to form an oxide film on the powder surface. It was found that the Al powder alloys can be firmly bonded to each other and the excellent rapid solidification characteristics can be maintained by chemically breaking and mechanically breaking the Al alloy powders.

Therefore, the method for producing an Al powder alloy according to one aspect of the present invention includes the following steps.

First, Mg is contained in an amount of 0.3% by weight or more and 1.5% by weight or less, Sn is contained in an amount of 0.3% by weight or more and 1.5% by weight or less, and the weight% of Mg is contained with respect to the weight% of Sn. At least one of an Al alloy powder having a ratio of 0.8 or more and 1.25 or less and the balance of Al and unavoidable impurities and a powder compact thereof are prepared. Then, at least one of the Al alloy powder and the powder compact thereof has a temperature of 400 ° C. or higher and 520 ° C. or lower.
Holds for more than a second. Then, at least one of the Al alloy powder and the powder compact thereof is hot compacted and solidified.

A method of manufacturing an Al powder alloy according to another aspect of the present invention includes the following steps.

First, Mg is contained in an amount of 0.3% by weight or more and 1.5% by weight or less, Sn is contained in an amount of 0.3% by weight or more and 1.5% by weight or less, and the weight% of Mg is contained with respect to the weight% of Sn. At least one of an Al alloy powder having a ratio of 0.8 or more and 1.25 or less and the balance of Al and unavoidable impurities and a powder compact thereof are prepared. Then, at least one of the Al alloy powder and the powder compact thereof is hot compacted and solidified in a mold heated to a temperature of 400 ° C. or higher and 520 ° C. or lower.

In the method for producing an Al powder alloy according to a preferred aspect of the present invention, the Al alloy powder is cooled at a cooling rate of 10 ² ° C / sec or more and 10 ⁴ ° C / sec or less by a rapid solidification spray method. To be prepared.

In the method for producing an Al powder alloy according to another preferred aspect of the present invention, the powder compact is prepared by molding the Al alloy powder at a temperature of room temperature or higher and 300 ° C. or lower.

A according to yet another preferred aspect of the present invention
In the method for producing a powder alloy, at least one of the Al alloy powder and the powder compact thereof is 400 ° C. or higher and 520 ° C.
The rate of raising the temperature to the following is 30 ° C./min or more.

A according to yet another preferred aspect of the present invention.
In the method for producing a powder alloy, the solidified body has a true density ratio of 97%.
It is hot-molded and solidified as described above.

A according to yet another preferred aspect of the present invention
In the method for producing a powder alloy, the Al alloy powder contains Fe in an amount of 2.0 wt% or more and 7.5 wt% or less, Ni in an amount of 2.0 wt% or more and 7.5 wt% or less, and the weight of Ni. It is prepared so that the content ratio of Fe weight% with respect to 100% is 0.8 or more and 1.25 or less.

A according to yet another preferred aspect of the present invention
In the method for producing a powder alloy, the Al alloy powder is prepared so as to further contain Si in an amount of 5% by weight or more and 40% by weight or less.

A according to yet another preferred aspect of the present invention A
In the method for producing a powder alloy, the Al alloy powder is prepared so as to further contain Cu in an amount of 1.0 wt% or more and 4.0 wt% or less and Mn in an amount of 0.2 wt% or more and 1.0 wt% or less. It

[0033]

In the Al powder alloy of the present invention, each component of the alloy and its content are limited. The action of each component of this alloy and its content will be described below.

[Contents of Sn and Mg] In the powder formed by the rapid solidification method because it has no eutectic reaction with Sn: Al, Sn is not alloyed with Al in the Al matrix and is uniform. Disperse into. By heating this powder, Sn generates a liquid phase and flows out from the inside of the powder to the surface of the powder. As a result, the oxide film on the surface of the powder can be divided and broken from the inside.

Mg: Upon heating, Mg easily diffuses in the Al matrix. For this reason, when the oxide film is destroyed by the liquid phase out of Sn as described above, Mg mutually diffuses between the adjacent powders (powder grain boundaries). This makes it possible to obtain a strong binding force between the powders.

Therefore, when both Sn and Mg coexist in the Al powder in proper amounts, the oxide film dividing / destroying effect by Sn and the mutual diffusion effect by Mg can be obtained for the first time, and the rapidly solidified Al alloy powders It is possible to realize a strong bond of.

When the addition amount of either or both of Mg and Sn is less than 0.3% by weight, or when the content ratio (Mg / Sn) is less than 0.8 or exceeds 1.25, However, it is not possible to obtain the effect of dividing and breaking the oxide film as described above and the effect of improving the bonding force between the powders due to mutual diffusion. Addition amount of Sn is 1.5
If the content exceeds 10% by weight, when the liquid phase of Sn flowing out to the powder surface is solidified at room temperature, it exists as coarse inclusions, and the bondability between the powders is rather deteriorated. Therefore, an Al powder alloy having sufficient strength cannot be obtained. Further, with respect to Mg, even if added in an amount of more than 1.5% by weight, the above effect is not improved.

Therefore, Mg is 0.3% by weight or more and 1.5
The content of Sn is 0.3 wt% or more and 1.5 wt% or less, and the content ratio of Mg wt% to Sn wt% (Mg / Sn) is 0.8 or more and 1.25 or less. There must be.

[Contents of Fe and Ni] When an Al alloy powder to which Fe and Ni are added in appropriate amounts is prepared by a rapid solidification spraying method, fine Al ₉ FeNi having a particle size of 0.2 μm or more and 3.0 μm or less is used. Spherical intermetallic compound consisting of Al
Disperse evenly in the matrix. As a result, the Al powder alloy solidified by hot forging is 150 ° C or higher and 200 ° C or higher.
It has a tensile strength of 40 kgf / mm ² or more in the following temperature range.

When one or both of Fe and Ni are added in an amount of less than 2.0% by weight, or when their content ratio (Fe / Ni) is less than 0.8 or exceeds 1.25, However, the fine Al ₉ FeNi intermetallic compound as described above is not generated. For this reason, it becomes difficult to obtain the above excellent heat resistance. Also, F
Even if one or both of e and Ni are added in an amount of more than 7.5% by weight, the effect on heat resistance is not improved, and the intermetallic compound dispersed in the Al matrix is rather coarsened or acicular. . For this reason, there arises a problem that the toughness and ductility of the solidified Al powder alloy are reduced.

Therefore, Fe is 2.0% by weight or more and 7.
5 wt% or less, Ni is contained in an amount of 2.0 wt% or more and 7.5 wt% or less, and Fe wt% relative to Ni wt%
The content ratio (Fe / Ni) of is preferably 0.8 or more and 1.25 or less.

[Si content] A containing an appropriate amount of Si
In the l alloy powder, Si crystal grains are uniformly dispersed in the Al matrix. Since the Si crystal grains are hard, the Al powder alloy has excellent wear resistance and seizure resistance. Moreover, the grain size of this Si crystal grain is 10 μm.
In the case of the following fineness, the strength and toughness of the Al powder alloy containing Si crystal grains do not deteriorate.

When the grain size of Si crystal grains is larger than 10 μm, when a large load is applied to the Al powder alloy containing the Si crystal grains, the Si crystal grains become a starting point of fracture and the Al powder alloy It causes deterioration of strength and toughness. When the Si content is less than 5% by weight, it is difficult to secure the excellent wear resistance and seizure resistance as described above.
Further, even if Si is added in an amount of more than 40% by weight, the effect of further improving the wear resistance is not recognized, and the strength and toughness of the Al powder alloy are rather deteriorated.

Therefore, it is desirable that Si is contained in an amount of 5% by weight or more and 40% by weight or less, and that the crystal grains of Si have a grain size of 10 μm or less.

Viewpoint of improving wear resistance of Al powder alloy
In addition to the above Si, Al₂ O ₃ , SiC, AlN
Al ceramics by rapid solidification method
It is also effective to use a powder that is uniformly dispersed in the powder.
It The amount of addition at that time is the same as that for Si.
The appropriate amount is 5% by weight or more and 40% by weight or less.

[Contents of Cu and Mn] Cu and M
n enhances mechanical properties such as strength and hardness of the Al powder alloy by solid solution strengthening, and precipitates in the Al matrix of the Al powder alloy to suppress coarsening of the intermetallic compound of Al ₉ FeNi described above. have.

When the added amount of Cu is less than 1% by weight, the above-mentioned effects of improving mechanical properties and suppressing coarsening of intermetallic compounds are insufficient. Even if Cu is added in an amount of more than 5% by weight, the effect is not improved and the corrosion resistance is reduced. If the addition amount of Mn is less than 0.2% by weight, the effect is insufficient. In addition, Mn is 1.0% by weight
If it is added in excess, the effect will not be improved, and coarse crystallized substances will be produced, which will conversely reduce the strength and toughness of the Al powder alloy.

Therefore, Cu is 1.0% by weight or more and 4.
It is desirable that the content of Mn is 0% by weight or less and the content of Mn is 0.2% by weight or more and 1.0% by weight or less.

Next, in the method for producing an Al powder alloy of the present invention, the production conditions are limited. The meaning of the limitation of these manufacturing conditions will be described below.

[Raw Material Powder] In the method for producing an Al powder alloy of the present invention, an Al powder alloy is obtained by molding and solidifying only an Al alloy powder having a predetermined component composition. Therefore, the Al alloy powder as the raw material and the Al powder alloy have the same composition.

Al powder alloy (P / M
I / M with the same composition as (Powder Metal) alloy
(Ingot Metal: Ingot Metal) Alloy has no effect of rapid solidification. In addition, in this I / M alloy, Sn and Mg are Al
It is not possible to disperse it uniformly in the matrix or to precipitate the intermetallic compound (Al ₉ FeNi) or Si finely and uniformly in the Al matrix. Therefore, it is difficult for the I / M alloy to secure the above characteristics. Therefore, in the method for producing an Al powder alloy of the present invention, the rapidly solidified Al alloy powder is used as the raw material.

As a method of rapidly solidifying, there is, for example, a rapidly solidifying spray method. If the cooling rate (quenching rate) of the powder in this rapid solidification spraying method is smaller than 10 ² ° C / sec, the crystal grains of the intermetallic compound (Al ₉ FeNi) and Si dispersed in the Al matrix become coarse. To do.
For this reason, the strength and toughness of the Al powder alloy obtained by this will fall. Also, the cooling rate of the powder is 10 ⁴
Even if it is higher than ° C / sec, no further remarkable improvement in strength and toughness of the Al powder alloy obtained by this is recognized, and the cost of the powder increases, which causes a problem in economic efficiency.

Therefore, it is desirable that the cooling rate of the powder in the rapid solidification spraying method is 10 ² ° C / sec or more and 10 ⁴ ° C / sec or less.

When a powder solidified body is manufactured by the hot forging method or the hot coining method using the rapidly solidified Al alloy powder having the above-mentioned composition, the transition element A such as Fe or Ni is used.
Since the diffusion coefficient for the l-matrix is small, an oxide film is regenerated on the powder surface when heated in the air, and the intermetallic compound becomes coarse and the toughness deteriorates due to holding for a long time, the production shown below. The conditions are correct.

[Fracture of oxide film] In the method for producing an Al powder alloy of the present invention, the oxide film on the surface of the Al alloy powder is mechanically and chemically destroyed to maintain the characteristics of rapid solidification, and the powder particles are kept together. Is a method of obtaining an Al powder alloy in which is strongly bonded. This manufacturing method has two modes.

Manufacturing method I: Mechanical destruction and chemical destruction of the oxide film are performed in separate steps. Manufacturing method II: Mechanical destruction and chemical destruction of the oxide film are performed in the same step.

Manufacturing Method I At least one of the Al alloy powder and the powder compact having the above component composition is rapidly heated to a temperature range of 400 ° C. or higher and 520 ° C. or lower and kept at that temperature for 10 seconds or longer. To be done. Then, at least one of the Al alloy powder and the powder compact is hot compacted and solidified to obtain a solidified body.

First, by raising the temperature to a predetermined temperature range and maintaining it under heating, coarsening of fine Si crystal grains and intermetallic compounds during quench solidification is suppressed, and the liquid phase of Sn dispersed in the powder is suppressed. The effect of generation and interdiffusion of Mg appears. Therefore, while maintaining the characteristics of rapid solidification, the oxide film on the powder surface is chemically divided and destroyed, and the powder is easily plastically deformed. Therefore, even if the Al alloy powder or the like is not heated to such a high temperature during the hot compaction and solidification, the surface oxide film can be easily mechanically destroyed by the hot compaction and solidification to obtain a sufficiently strong powder bond. Therefore, the powders can be firmly bonded to each other under a thermal history (heating temperature / time) that does not impair the fine structure obtained by rapid solidification.

Further, since it is likely to be plastically deformed, when this hot forming and solidification is carried out by a hot forging method using, for example, a closed die, the solidified body obtained by this has a relative density of 97% or more. Densified. As a result, it becomes possible to manufacture a good Al powder alloy having sufficient strength and toughness.

Regarding the heating temperature range, the heating temperature is 520
If the temperature exceeds ℃, fine Si crystal grains and intermetallic compounds in the Al alloy powder and the powder compact become coarse. When the heating temperature is lower than 400 ° C., the liquid phase formation of Sn dispersed in the Al matrix of the Al alloy powder and the diffusion phenomenon of Mg are suppressed. Therefore, Al
Since the oxide film on the surface of the alloy powder is not sufficiently divided / broken, and a strong bond between the powders cannot be obtained, the strength of the Al powder alloy is reduced.

Regarding the heating and holding time, 400 ° C. or higher 52
If the temperature is kept at 0 ° C or lower for less than 10 seconds, A
The liquid phase generation of Sn dispersed in the Al matrix of the 1-alloy powder and the diffusion phenomenon of Mg are suppressed. For this reason, the oxide film on the surface of the Al alloy powder is not sufficiently divided and broken, and a strong bond between the powders cannot be obtained, so that the strength of the Al powder alloy decreases.

However, in the above temperature range, even if the heating is performed for a long time, the crystal grains of Si and the intermetallic compound are not significantly coarsened. However, the heating and holding time is 1 hr. It is preferably about the following.

The rate of raising the temperature to the above temperature range during heating is preferably 30 ° C./minute or more. Under such a temperature rising condition, no remarkable regeneration of the oxide film on the powder surface that would hinder the binding between the powder particles occurs.

When heating at a temperature rising rate of less than 30 ° C./minute, the heating atmosphere is an inert gas atmosphere such as nitrogen (N) or argon (Ar) from the viewpoint of suppressing the oxidation of the Al alloy powder. Is desirable.

If the powder is hard, problems such as cracks in the powder compact or partial lack of powder occur during embossing and molding. In such a case, it is preferable that the Al alloy powder is annealed and heated at a temperature of 300 ° C. or lower to be softened, and then embossed and molded. In this case, if the temperature exceeds 300 ° C., the surface of the Al alloy powder is remarkably oxidized and an oxide film is regenerated. For this reason, the binding property between the powders is rather deteriorated, and it becomes impossible to manufacture an Al powder alloy having sufficient strength.

Manufacturing Method II Manufacturing method II is characterized by being more economical than manufacturing method I. That is, the rapid solidification A having a predetermined composition
At least one of the 1-alloy powder and the powder compact thereof is directly filled in a mold heated to a temperature range of 400 ° C. or higher and 520 ° C. or lower, and then immediately hot pressed and solidified by pressure compression. By promoting mechanical destruction and chemical destruction of the surface oxide film during hot compaction and solidification of at least one of the Al alloy powder and the powder compact, the heating / heating / heating step before hot compaction and solidification can be performed. It can be omitted.

The powder and the like are sufficiently heated to a predetermined temperature range by the heat conduction from the mold until the heated mold is filled with the powder and pressed and compressed. For this reason,
The effects of the liquid phase generation of Sn and the interdiffusion of Mg as described above are exhibited, the oxide film on the powder surface is chemically divided and destroyed, and the powder is easily plastically deformed. In this state, the powder is plastically deformed by pressure and compression in the mold, so that the oxide film on the powder surface is mechanically destroyed by a small amount of heat.

As a result, the powder solidified body is densified to a true density ratio of 97% or more by pressure compression in the closed mold, and it is possible to produce a good Al powder alloy having sufficient strength and toughness. Become.

In the powder solidified body, when the true density ratio is less than 97%, the voids existing in the solidified body become the starting points of fracture and induce the reduction of the strength of the alloy. Therefore, it is desirable to perform hot compaction and solidification so that the solidified body becomes dense with a true density ratio of 97% or more.

Furthermore, in the present alloy system, it is possible to use a solution age hardening matrix. For this reason 150
In order to improve the strength and hardness of the Al powder alloy in the temperature range of ℃ or less, it is effective to carry out T4 heat treatment or T6 heat treatment as necessary.

[0071]

EXAMPLE 1 FIG. 1 is a block diagram showing a method for producing an Al powder alloy in Example 1 of the present invention.

Referring to FIG. 1, first, rapidly solidified Al alloy powder (average particle size 80 μm) having the alloy composition shown in Table 1 was prepared (step 11). This rapidly solidified aluminum alloy powder was press-molded at room temperature to 45 × 10 × 10 mm (surface pressure: 4 t / cm ² ) to obtain a compact (step 1
2). This molded body is heated to 500 ° C in the atmosphere in a high frequency heating furnace
The temperature was raised to 100 ° C./minute (heating rate 100 ° C./min), and the temperature (500 ° C.) was maintained for 30 seconds (step 13).
Immediately thereafter, the molded body was closed in the mold (mold temperature 280
C.), and hot solidified into a shape of 46 × 11 × 6 mm (true density ratio 100%) by pressure compression (surface pressure: 7 t / cm ² ) (step 14).

Tensile strength (UTS) and elongation at break of the Al powder alloy thus produced were measured. The measurement results are shown in Table 1.

[0074]

[Table 1]

Material No. of the present invention Nos. 1 to 6 are Al powder alloys obtained by hot-solidifying rapidly solidified Al alloy powders containing appropriate amounts of Sn and Mg under appropriate manufacturing conditions, and have excellent tensile strength and elongation. Shows.

On the other hand, comparative material No. In Nos. 7 to 10, good tensile strength and elongation were not obtained as follows.

No. 7: Due to the small amount of Sn and Mg, the effect of dividing / destroying the oxide film on the powder surface and the mutual diffusion effect are not sufficiently expressed, and as a result, a strong bond between the powders is not obtained and good strength / elongation is obtained. There wasn't.

No. 8: Due to the large amount of Sn, the Sn phase flowing out to the old powder grain boundaries of the alloy by heating solidified to form coarse inclusions, and as a result, good strength and elongation were not obtained.

No. 9: The content ratio of Sn / Mg is not appropriate, so that the effect of dividing / destroying the oxide film on the powder surface and the mutual diffusion effect are not sufficiently exhibited, resulting in a strong bond between the powders and good strength / No growth was obtained.

No. Since the content ratio of 10: Sn / Mg is not appropriate, the effect of dividing / destroying the oxide film on the powder surface and the mutual diffusion effect are not sufficiently exhibited, resulting in a strong bond between the powders and good strength. No growth was obtained.

Example 2 A rapidly solidified Al alloy powder (average particle size 80 μm) having an alloy composition shown in Table 2 was press-molded (face pressure: 4 t / cm ² ) into 45 × 10 × 10 mm at room temperature, and molded. Got the body This molded body was heated up to 500 ° C. in the atmosphere using a high-frequency heating furnace (heating rate 100 ° C./min) and heated at that temperature for 30 minutes.
Hold for a second. Immediately thereafter, the molded body was inserted into a closed mold (mold temperature: 280 ° C.), and compressed under pressure (contact pressure: 7 t).
/ Cm ² ) 46 x 11 x 6 mm shape (true density ratio 1
Hot solidified to 00%).

The tensile strength (UTS) of the Al powder alloy thus produced at room temperature and 180 ° C. was measured. Also, Al ₉ FeNi dispersed in the Al matrix
The average particle size (D0) of the intermetallic compound was investigated. The results are shown in Table 2 below. The tensile test at 180 ° C. was performed after the sample was heat-treated at a temperature of 180 ° C. for 100 hours.

[0083]

[Table 2]

Material No. of the present invention 1 to 5 are appropriate amounts of Sn and M
It is an alloy obtained by hot-solidifying a rapidly solidified Al alloy powder containing g, Fe, and Ni under appropriate manufacturing conditions, and has excellent tensile strength at room temperature and high temperature, respectively. In particular, the intermetallic compound of Al ₉ FeNi in the Al matrix has a fine average particle size of 3 μm or less in each alloy and is uniformly dispersed. As a result, the tensile strength at 180 ° C. exceeds 40 kgf / mm ² . ing.

On the other hand, comparative material No. Regarding 6 to 9, good tensile strength was not obtained as follows.

No. 6: Poor heat resistance due to small amounts of Fe and Ni, and as a result, good tensile strength could not be obtained at 180 ° C.

No. 7: The intermetallic compound Al ₉ FeNi became coarse due to the large amounts of Fe and Ni, and good tensile strength could not be obtained at 180 ° C.

No. 8: Since the content ratio of Fe / Ni is not appropriate, the intermetallic compound Al ₉ FeNi becomes coarse,
As a result, good tensile strength was not obtained at 180 ° C.

No. The intermetallic compound Al ₉ FeNi was coarsened because the ratio of 9: Fe / Ni was not appropriate, and as a result, good tensile strength at 180 ° C. could not be obtained.

Example 3 A rapidly solidified Al alloy powder (average particle size 80 μm) having an alloy composition shown in Table 3 was press-molded (face pressure: 4 t / cm ² ) into 45 × 10 × 10 mm at room temperature and molded. Got the body This molded body was heated and heated to 500 ° C. in the atmosphere using a high frequency heating furnace (heating rate 100 ° C./min), and the temperature (50
Hold at 0 ° C for 30 seconds. Immediately thereafter, the molded body was inserted into a closed mold (mold temperature: 280 ° C.), and heated to a 46 × 11 × 6 mm shape (true density ratio 100%) by pressure compression (surface pressure: 7 t / cm ² ). It solidified. However, No. 1 in Table 3 Samples 8 and 9 were prepared by heating to 550 ° C. in the atmosphere, holding at that temperature for 30 seconds, and then hot solidifying under the conditions described above.

In Table 3, No. In the sample of 5,
Instead, Al with an average particle size of 5 μm₂ o ₃ Containing 20% by weight
Used powder.

The tensile strength (UTS) at room temperature, the elongation at break, and the wear resistance of the Al powder alloy thus produced were evaluated. For evaluation of this wear resistance property,
A ring-on-ring abrasion tester as shown in FIG. 3 was used.

Referring to FIG. 3, an upper sample 1 and a lower sample 3 are prepared, the upper sample 1 is fixed, and a pressing force P (= 60 kgf / cm) is applied to a sliding surface between the upper sample 1 and the lower sample 3. ² ), the lower sample 3 is rotated at a peripheral velocity v (= 2.0 m / sec.), And the upper sample 1 and the lower sample 3 are moved for 1 hr. It was slid. This sliding was performed in ATF oil.

The average grain size (D1) of the Si crystal grains dispersed in the Al matrix (matrix) was examined by optical microscope observation. The results are shown in Table 3 below.

[0095]

[Table 3]

Material No. of the present invention 1 to 5 are appropriate amounts of Sn and M
g and Si (No. 5 is Al₂ O ₃ ) Containing
Hot powder solidification of solidified Al alloy powder under appropriate manufacturing conditions
Alloys, which have tensile strength, elongation and resistance at room temperature.
It has excellent wear resistance. In particular, Si in Al matrix
Grain size of each alloy is 10 μm or less
As a result of having a particle size and uniformly dispersing, in ATF oil
Co-sliding sliding (friction sliding between same materials) is possible
It

On the other hand, comparative material No. In Nos. 6 to 11, good properties could not be obtained in any of tensile strength, elongation and wear resistance as described below.

No. 6: Since the amount of Si was 0, seizure (adhesion) occurred with the counterpart agent, and as a result, the amount of wear damage was remarkably large.

No. 7: Since the amount of Si was small, seizure (adhesion) occurred with the counterpart agent, and as a result, the amount of wear damage was remarkably large.

No. 8: Since the heating temperature of the molded body was as high as 550 ° C., the Si crystal grains were coarsened to about 25 μm during heating, and as a result, the Al powder alloy had good strength.
No growth was obtained.

No. 9: Since the heating temperature of the molded body was as high as 550 ° C., the Si crystal grains were coarsened to about 30 μm during heating, and as a result, the Al powder alloy had good strength.
No growth was obtained.

No. Since the content ratio of 10: Sn / Mg is not appropriate, the effect of dividing / destroying the oxide film on the powder surface and the mutual diffusion effect are not sufficiently exhibited, resulting in no strong bond between the powders and good strength.・ No growth was obtained.

No. 11: The content ratio of Sn / Mg is not appropriate, so that the effect of dividing / destroying the oxide film on the powder surface and the mutual diffusion effect are not sufficiently exhibited, resulting in a strong bond between the powders and good strength No growth was obtained.

Example 4 A rapidly solidified Al alloy powder (average particle size 80 μm) having the alloy composition shown in Table 4 was press-molded (face pressure: 4 t / cm ² ) at room temperature to 45 × 10 × 10 mm, and molded. Got the body This molded body was heated and heated to 500 ° C. in the atmosphere using a high-frequency heating furnace (heating rate: 100 ° C./min), and the temperature (5
The temperature was held at 00 ° C for 30 seconds. Immediately thereafter, this molded body was inserted into a closed mold (mold temperature: 280 ° C.) and compressed by pressure (surface pressure: 7 t / cm ² ) to 46 × 11 × 6 mm.
It was hot solidified into a shape (true density ratio 100%). The tensile strength (UT) of the Al powder alloy thus produced at room temperature
S) and elongation at break were measured. The results are shown in Table 4 above.

[0105]

[Table 4]

Material No. of the present invention 1 to 4 are appropriate amounts of Sn and M
Rapid solidification Al containing g, Fe, Ni and Si
The alloy powder is an alloy obtained by hot powder solidification under appropriate manufacturing conditions, and each has excellent tensile strength and elongation at room temperature.

On the other hand, comparative material No. Regarding 5 to 7, good tensile strength and elongation were not obtained as follows.

No. 5: Since the amount of Sn is small and the amount of Mg is 0, the effect of dividing / destroying the oxide film on the powder surface and the mutual diffusion effect are not exhibited, resulting in a strong bond between the powders and good strength. No growth was obtained.

No. 6: As the content ratio of Sn / Mg is not proper, the effect of dividing / destroying the oxide film on the powder surface and the mutual diffusion effect are not sufficiently expressed, resulting in a strong bond between the powders and good tensile strength.・ No growth was obtained.

No. 7: Since the content ratio of Sn / Mg is not appropriate, the effect of dividing / destroying the oxide film on the powder surface and the mutual diffusion effect are not sufficiently expressed, and as a result, a strong bond between the powders is not obtained and good tensile strength is obtained.・ No growth was obtained.

Example 5 A rapidly solidified Al alloy powder (average particle size 80 μm) having an alloy composition shown in Table 5 was hot solidified under the respective production conditions shown in Table 6. The true density ratio, tensile strength (UTS) at room temperature, and elongation at break of the Al powder alloy thus obtained were measured. The results are shown in Table 6 above.

However, alloy No. Only T3 was heat-solidified to T6 heat treated sample (470 ℃ × 2hr. → water cooling → 175 ℃
× 8 hr. (→ air cooling).

In Table 6, the unit of temperature is ° C, the unit of surface pressure is t / cm ² , the unit of temperature rising rate is ° C / min, and the unit of holding time is second.

Further, as shown in FIG. 2, alloy Nos. 7, 8 and 15 in Table 6 were prepared by rapid compaction of the prepared Al alloy powder (step 21) and then directly hot solidified (step 22). It is a thing.

[0115]

[Table 5]

[0116]

[Table 6]

Material No. of the present invention 1 to 8 are rapid solidification A having an appropriate alloy composition according to the appropriate manufacturing conditions in the present invention.
1 is an alloy powder hot-solidified. Further, according to the production method of the present invention, it is possible to solidify the powder to a true density ratio of 98% or more, and it is possible to produce an Al powder alloy excellent in both tensile strength and elongation at room temperature. further,
It is possible to further improve the strength by subjecting the alloy obtained by hot-solidifying the powder to which appropriate amounts of Cu and Mn are added to T6 heat treatment.

On the other hand, a comparative material No. No. obtained by hot solidifying a rapidly solidified Al alloy powder having a predetermined composition by a comparative manufacturing method. 9 ~
Regarding No. 15, it was not possible to obtain excellent tensile strength and elongation as described below.

No. 9: The heating temperature of the powder compact is 380
Since the temperature is as low as 0 ° C., the effect of adding Sn and Mg is not sufficiently exhibited, so that a strong bond between the powders cannot be obtained and excellent tensile strength / elongation cannot be obtained.

No. 10: The heating temperature of the powder compact is 56
Intermetallic compound Al due to high temperature of 0 ℃ ₉ FeNi and S
As a result of the coarsening of the crystal grains of i, excellent tensile strength and elongation
I couldn't get it.

No. 11: Since heating and holding were carried out under conditions where the temperature rising rate was as low as 10 ° C./min in the air atmosphere,
An oxide film was regenerated on the powder surface, and as a result, excellent tensile strength and elongation were not obtained.

No. 12: Since the heating and holding time of the powder compact was as short as 2 seconds, the effect of adding Sn and Mg was not sufficiently exhibited, so that a strong bond between the powders was not obtained and excellent tensile strength and elongation were obtained. There wasn't.

No. 13: Since the heating and holding time of the powder compact was as short as 5 seconds, the effect of adding Sn and Mg was not sufficiently exhibited, so that a strong bond between the powders was not obtained and excellent tensile strength and elongation were obtained. There wasn't.

No. 14: Pressing force during hot solidification is 2 t /
Since it is as small as cm ² , the powders are not firmly bonded to each other, and as a result, the true density ratio of the powder solidified body is 89%,
Due to the presence of pores inside, excellent tensile strength and elongation could not be obtained.

No. 15: In the manufacturing method in which the powder compact is directly inserted into the heated mold and compressed under pressure, the mold temperature is as low as 360 ° C., and the powder compact is not heated sufficiently, so the effect of adding Sn and Mg is sufficient. Does not appear in As a result, the powders were not sufficiently bonded to each other, the true density ratio of the powder solidified body was 95%, and voids were present inside, so that excellent tensile strength and elongation could not be obtained.

[0126]

According to the present invention, the Al alloy powder containing appropriate amounts of Sn and Mg is heated at elevated temperatures under appropriate conditions, whereby the surface oxide film is divided / destructed by the outflow of Sn in the liquid phase. Due to the mutual diffusion effect of Mg, the powders are strongly bonded to each other and the powders are easily plastically deformed.
As a result, the Al alloy powder can be molded and solidified with a small heat history, the characteristics of the rapid solidification method can be maintained, and an Al powder alloy in which the powder particles are firmly bonded to each other can be obtained. It is also possible to produce an Al powder alloy having excellent heat resistance and wear resistance by dispersing transition metal elements such as Fe and Ni and hard particles such as Si and ceramics.

Therefore, the material of the present invention can be used for sliding parts for compressors (vanes, rotors), parts for oil pumps, engine parts such as pistons, cylinders, connecting rods, etc. for wear-resistant sliding performance and heat resistance. The required automobile parts and home appliance parts are conceivable.

[Brief description of drawings]

FIG. 1 is a block diagram showing one embodiment of a method for producing an Al powder alloy of the present invention.

FIG. 2 is a block diagram showing another embodiment of the method for producing an Al powder alloy of the present invention.

FIG. 3 is a diagram showing how wear resistance characteristics are measured by a ring-on-ring wear tester.

Claims (17)

[Claims] 1. A Mg content of 0.3% by weight or more and 1.5% by weight or less, Sn of 0.3% by weight or more and 1.5% by weight or less, and a weight% of Mg relative to a weight% of Sn. An aluminum powder alloy whose content ratio (Mg / Sn) is 0.8 or more and 1.25 or less, and the balance is substantially Al and inevitable impurities. 2. Fe is contained in an amount of 2.0% by weight or more and 7.5% by weight or less, Ni is contained in an amount of 2.0% by weight or more and 7.5% by weight or less, and the weight% of Fe is relative to the weight% of Ni. The aluminum powder alloy according to claim 1, wherein the content ratio (Fe / Ni) is 0.8 or more and 1.25 or less. 3. A part of the Al is contained in the aluminum powder alloy as an intermetallic compound composed of Al ₉ FeNi, and the intermetallic compound composed of Al ₉ FeNi has a grain size of 0.2 μm or more and 3.0 μm or less. The aluminum powder alloy according to claim 2, which has a diameter and is uniformly dispersed. 4. A temperature of 150 ° C. or more and 200 ° C. or less
40kgf / mm ² Claims having the above tensile strength
3. The aluminum powder alloy according to item 3. 5. The aluminum powder alloy according to claim 1, which contains Si in an amount of 5% by weight or more and 40% by weight or less. 6. The aluminum powder alloy according to claim 5, wherein the Si crystal grains have a grain size of 10 μm or less. 7. Cu is contained in an amount of 1.0% by weight or more and 4.0% by weight or less, and Mn is contained in an amount of 0.2% by weight or more and 1.0% by weight or less. An aluminum powder alloy according to any one of claims 1, 2 and 5. 8. The Mg content is 0.3 wt% or more and 1.5 wt% or less, the Sn content is 0.3 wt% or more and 1.5 wt% or less, and the Mg wt% relative to the Sn wt%. A content ratio (Mg / Sn) of 0.8 or more and 1.25 or less, with the balance being substantially Al and unavoidable impurities, and at least one of an aluminum alloy powder and a powder compact thereof. , At least one of the aluminum alloy powder and the powder compact thereof at a temperature of 400 ° C. or higher and 520 ° C. or lower
A method for producing an aluminum powder alloy, comprising: a step of holding for 0 seconds or more; and a step of hot compacting and solidifying at least one of the aluminum alloy powder and a powder compact thereof. 9. The Mg content is 0.3 wt% or more and 1.5 wt% or less, the Sn content is 0.3 wt% or more and 1.5 wt% or less, and the Mg wt% is relative to the Sn wt%. A content ratio (Mg / Sl) of 0.8 or more and 1.25 or less, the balance of which is substantially Al and at least one of an aluminum alloy powder which is an unavoidable impurity and a powder compact thereof. And a step of hot forming and solidifying at least one of the aluminum alloy powder and the powder compact thereof in a mold heated to a temperature of 400 ° C. or higher and 520 ° C. or lower. 10. The aluminum alloy powder according to claim 8, wherein the aluminum alloy powder is prepared by cooling the molten aluminum alloy at a cooling rate of 10 ² ° C./sec or more and 10 ⁴ ° C./sec or less by a rapid solidification spraying method. A method for producing an aluminum powder alloy according to claim 1. 11. The method for producing an aluminum powder alloy according to claim 8, wherein the powder compact is prepared by molding the aluminum alloy powder at a temperature of room temperature or higher and 300 ° C. or lower. 12. The aluminum alloy powder and / or at least one of the powder compacts thereof is heated to 400.degree.
The rate of raising the temperature to ℃ or less is 30 ℃ / min or more,
A method for producing the aluminum powder alloy according to claim 8. 13. The method for producing an aluminum powder alloy according to claim 8, wherein the solidified body is hot-molded and solidified so that the true density ratio becomes 97% or more. 14. The aluminum alloy powder contains Fe in an amount of 2.0 wt% or more and 7.5 wt% or less, Ni in an amount of 2.0 wt% or more and 7.5 wt% or less, and the weight of Ni. Content ratio of Fe weight% to Fe% (Fe / Ni)
Is prepared to be 0.8 or more and 1.25 or less. 15. The aluminum alloy powder is the A
Some of l are contained in the aluminum powder alloy intermetallic compound composed of Al ₉ FeNi, the Al ₉ F
Intermetallic compound consisting of eNi 0.2μm or more 3.0μ
The method for producing an aluminum powder alloy according to any one of claims 8, 9 and 14, which has a particle diameter of m or less and is prepared so as to be uniformly dispersed. 16. The method for producing an aluminum powder alloy according to claim 8, wherein the aluminum alloy powder is prepared such that Si is contained in an amount of 5% by weight or more and 40% by weight or less. 17. The aluminum alloy powder is prepared such that Cu is contained in an amount of 1.0 wt% or more and 4.0 wt% or less and Mn is 0.2 wt% or more and 1.0 wt% or less. A method for producing an aluminum powder alloy according to any one of claims 8, 9, 14 and 15.