ALUMINUM ALLOY POWDER AND PRODUCTION METHOD THEREOF, AND ALUMINUM ALLOY EXTRUDED MATERIAL AND PRODUCTION METHOD THEREOF

- SHOWA DENKO K.K.

An aluminum alloy powder consists of Fe: 5.0 mass % to 9.0 mass %, V: 0.1 mass % to 3.0 mass %, Mo: 0.1 mass % to 3.0 mass %, Zr: 0.1 mass % to 2.0 mass %, Ti: 0.02 mass % to 2.0 mass %, and the balance being Al and inevitable impurities. The aluminum alloy powder contains an Al—Fe based intermetallic compound. An average circle equivalent diameter of the Al—Fe based intermetallic compound is in a range of 0.1 μm to 3.0 μm in a cross-sectional structure of the aluminum alloy powder. An aluminum alloy extruded material excellent in mechanical properties at high temperature is provided.

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Description
BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an aluminum alloy powder excellent in mechanical properties at high temperature and a production method thereof, and an aluminum alloy extruded material (extruded product) excellent in mechanical properties at high temperature and a production method thereof.

Description of the Related Art

The following description sets forth the inventor's knowledge of related art and problems therein and should not be construed as an admission of knowledge in the prior art.

A compressor impeller, such as, e.g., a compressor wheel of a turbocharger for use in an automobile internal combustion engine is rotated at high speed exceeding 10,000 rpm under high temperature conditions of about 150° C. For this reason, it is required to have high strength and high rigidity under such high temperature. Further, the compressor impeller is required to attain the weight reduction in order to reduce the energy loss, and also required to have strength capable of withstanding a high speed rotation.

For example, conventionally, a compressor impeller is produced by subjecting a cast/forged product of a 2618 alloy (an alloy consisting of Cu: 1.9 mass % to 2.7 mass %, Mg: 1.3 mass % to 1.8 mass %, Ni: 0.9 mass % to 1.2 mass %, Fe: 0.9 mass % to 1.3 mass %, Si: 0.1 mass % to 0.25 mass %, Ti: 0.04 mass % to 0.1 mass %, the balance being Al and inevitable impurities) to a cutting process.

However, due to the recent increase in cutting process speed, producing a product by cutting an aluminum alloy extruded material has been progressed, which requires further improvement of the cutting ability and the high temperature strength of the material.

For example, Patent Document 1 discloses a technique of providing an Al—Cu—Mg based aluminum alloy extruded material improved in strength at high temperature (160° C.) as compared with a conventional one. That is, Patent Document 1 describes a heat resistant aluminum alloy extruded material excellent in high temperature strength and high temperature fatigue properties, wherein the aluminum alloy consists of Cu: 3.4 to 5.5% (“%” denotes “mass %”, hereinafter the same), Mg: 1.7 to 2.3%, Ni: 1.0 to 2.5%, Fe: 0.5 to 1.5%, Mn: 0.1 to 0.4%, Zr: 0.05 to 0.3%, Si: less than 0.1%, Ti: less than 0.1%, and the balance being Al and inevitable impurities.

Patent Document 1: Japanese Patent No. 5284935

Problems to be Solved by the Invention

By the way, in the technical field of an internal combustion engine for automobiles or the like, a compressor impeller and the like are required to rotate at higher speeds. Therefore, as an aluminum alloy material for use as a constituent material of a compressor impeller, etc., an aluminum alloy material further excellent in mechanical properties even in a temperature range higher than that of a conventional temperature range has been demanded. Further, as the properties required for these materials, besides the static strength, it is also required that the dynamic strength, such as, e.g., creep properties, is excellent.

SUMMARY OF THE INVENTION

The present invention has been made in view of the aforementioned technical background, and aims to provide an aluminum alloy powder excellent in mechanical properties at high temperature and a production method thereof, and an aluminum alloy extruded material excellent in mechanical properties at high temperature and a production method thereof.

Means for Solving the Problems

In order to attain the aforementioned object, the present invention provides the following means.

[1] An aluminum alloy powder consisting of Fe: 5.0 mass % to 9.0 mass %, V: 0.1 mass % to 3.0 mass %, Mo: 0.1 mass % to 3.0 mass %, Zr: 0.1 mass % to 2.0 mass %, Ti: 0.02 mass % to 2.0 mass %, and the balance being Al and inevitable impurities,

    • wherein the aluminum alloy powder contains an Al—Fe based intermetallic compound, and
    • wherein an average circle equivalent diameter of the Al—Fe based intermetallic compound is in a range of 0.1 μm to 3.0 μm in a cross-sectional structure of the aluminum alloy powder.

[2] The aluminum alloy powder as recited in the aforementioned Item [1] further consisting of 0.0001 mass % to 0.03 mass % of B.

[3] A production method of an aluminum alloy powder, comprising:

    • quench-solidifying a molten metal of an aluminum alloy by an atomizing method into powder to obtain an aluminum alloy powder,
    • wherein the aluminum alloy consists of Fe: 5.0 mass % to 9.0 mass %, V: 0.1 mass % to 3.0 mass %, Mo: 0.1 mass % to 3.0 mass %, Zr: 0.1 mass % to 2.0 mass %, Ti: 0.02 mass % to 2.0 mass %, and the balance being Al and inevitable impurities.

[4] An aluminum alloy extruded material consisting of Fe: 5.0 mass % to 9.0 mass %, V: 0.1 mass % to 3.0 mass %, Mo: 0.1 mass % to 3.0 mass %, Zr: 0.1 mass % to 2.0 mass %, Ti: 0.02 mass % to 2.0 mass %, and the balance being Al and inevitable impurities,

    • wherein the aluminum alloy extruded material contains an Al—Fe based intermetallic compound, and
    • wherein an average circle equivalent diameter of the Al—Fe based intermetallic compound is in a range of 0.1 μm to 3.0 μm in a cross-sectional structure of the aluminum alloy extruded material.

[5] The aluminum alloy extruded material as recited in the aforementioned Item [4], wherein the aluminum alloy extruded material further contains 0.0001 mass % to 0.03 mass % of B.

[6] The aluminum alloy extruded material as recited in the aforementioned Item [4] or [5],

    • wherein the intermetallic compound is an Al—Fe—V—Mo based intermetallic compound containing at least Al, Fe, V, and Mo, and
    • wherein in the intermetallic compound, a content rate of Al is 81.60 mass % to 92.37 mass %, a content rate of Fe is 2.58 mass % to 10.05 mass %, a content rate of V is 1.44 mass % to 4.39 mass %, and a content rate of Mo is 2.45 mass % to 3.62 mass %.

[7] A production method of an aluminum alloy extruded material, comprising:

    • a compression molding step of compression molding the aluminum alloy powder recited in the aforementioned Item [1] or [2] to obtain a green compact; and
    • an extrusion step of hot extruding the green compact to obtain an extruded material,
    • wherein the extruded material contains an Al—Fe based intermetallic compound in the extruded material, and
    • wherein in a cross-sectional structure of the extruded material, an average circle equivalent diameter of the Al—Fe based intermetallic compound is in a range of 0.1 μm to 3.0 μm.

Effects of the Invention

According to the invention recited in the aforementioned Item [1], an aluminum alloy powder excellent in mechanical properties at high temperature is provided. Therefore, by using this aluminum alloy powder, it is possible to produce an aluminum alloy extruded material (extruded product) excellent in mechanical properties (static strength, creep properties, etc.) at high temperature.

According to the invention recited in the aforementioned Item [2], an aluminum alloy powder further improved in mechanical properties (values) at high temperature is provided.

According to the invention recited in the aforementioned Item [3], the molten metal of the aluminum alloy is quench-solidified by an atomizing method into powder. Therefore, diffusion of each element of the alloy during the solidification can be suppressed, and coarsening of crystal grains and precipitates can be suppressed. Furthermore, appearance of equilibrium phases and metastable phases can be suppressed. This increases the solid solution amount of Fe which is a transition element. Therefore, it is possible to produce an aluminum alloy powder excellent in mechanical properties (static strength, creep properties, etc.) at high temperature. For this reason, by using this aluminum alloy powder, it is possible to produce an aluminum alloy extruded material (extruded product) excellent in mechanical properties at high temperature.

According to the invention recited in the aforementioned Item [4], an aluminum alloy extruded material (extruded product) excellent in mechanical properties (static strength, creep properties, etc.) at high temperature is provided. This aluminum alloy extruded material is suitably used as an internal combustion engine member, such as, e.g., a turbo compressor impeller of a turbocharger for automobiles. In other words, this aluminum alloy extruded material is suitably used, for example, as an internal combustion engine member (internal combustion engine parts) configured to be rotated at high speed at high temperature.

According to the invention recited in the aforementioned Item [5], an aluminum alloy extruded material further improved in mechanical properties (value) at high temperature is provided.

According to the invention recited in the aforementioned Item [6], an aluminum alloy extruded material further improved in mechanical properties (value) at high temperature is provided.

According to the invention recited in the aforementioned Item [7], an aluminum alloy extruded material (extruded product) excellent in mechanical properties (static strength, creep properties, etc.) at high temperature is provided. The obtained aluminum alloy extruded material is suitably used as an internal combustion engine member, such as, e.g., a turbo compressor impeller of a turbocharger for automobiles. In other words, the obtained aluminum alloy extruded material is suitably used, for example, as an internal combustion engine member (internal combustion engine parts) configured to be rotated at high speed at high temperature.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing an example of an aluminum alloy extruded material (extruded product) of the present invention.

 EMBODIMENT FOR CARRYING OUT THE INVENTION

An aluminum alloy powder according to the present invention is an aluminum alloy powder consisting of Fe: 5.0 mass % to 9.0 mass %, V: 0.1 mass % to 3.0 mass %, Mo: 0.1 mass % to 3.0 mass %, Zr: 0.1 mass % to 2.0 mass %, Ti: 0.02 mass % to 2.0 mass %, and the balance being Al and inevitable impurities, wherein the aluminum alloy powder contains an Al—Fe based intermetallic compound, and wherein an average circle equivalent diameter of the Al—Fe based intermetallic compound is in a range of 0.1 μm to 3.0 μm in a cross-sectional structure of the aluminum alloy powder. With such a configuration, an aluminum alloy powder excellent in mechanical properties at high temperature is provided. Therefore, by using the aluminum alloy powder of the present invention, it is possible to produce an aluminum alloy extruded material (extruded product) excellent in mechanical properties (static strength, creep properties, etc.) at high temperature.

The average particle diameter of the aluminum alloy powder is not particularly limited, but it is preferable in the range of 30 μm to 70 μm. When it is 30 μm or more, the yield of the alloy powder production can be markedly improved, and when it is 70 μm or less, contamination of coarse oxides and/or foreign substances can be avoided.

Next, the production method of the aluminum alloy powder according to the present invention will be described. In this production method, a molten metal of an aluminum alloy consisting of Fe: 5.0 mass % to 9.0 mass %, V: 0.1 mass % to 3.0 mass %, Mo: 0.1 mass % to 3.0 mass %, Zr: 0.1 mass % to 2.0 mass %, Ti: 0.02 mass % to 2.0 mass %, and the balance being Al and inevitable impurities is quench-solidified by an atomizing method into powder to thereby obtain an aluminum alloy powder (Powdering Step). With such a production method, it is possible to provide an aluminum alloy powder having the above-mentioned configuration. In other words, according to the aforementioned production method, an aluminum alloy powder of the aforementioned specific composition in which an Al—Fe based intermetallic compound is contained in the aluminum alloy powder and an average circle equivalent diameter of the Al—Fe based intermetallic compound is in a range of 0.1 μm to 3.0 μm in a cross-sectional structure of the aluminum alloy powder can be produced.

In the powdering step, the aluminum alloy molten metal having the aforementioned specific composition is prepared by an ordinary dissolution method. The obtained aluminum alloy molten metal is powdered by an atomizing method. The atomizing method is a method in which fine droplets of the molten aluminum alloy are misted by a flow of a gas, such as, e.g., a nitrogen gas, from a spray nozzle and sprayed to quench-solidify fine droplets to obtain a fine aluminum alloy powder material. The cooling rate is preferably set from 102 to 105° C./second. It is preferable so that an aluminum alloy powder having an average particle diameter of 30 μm to 70 μm can be obtained. It is preferable to classify the obtained aluminum alloy powder using a sieve.

Note that the aluminum alloy powder (the invention recited in the aforementioned Item [1]) according to the present invention is not limited to the aluminum alloy powder obtained by the aforementioned production method, but also includes those obtained by other production methods.

Next, the production method of an aluminum alloy extruded material according to the present invention will be described. The aluminum alloy powder obtained in the aforementioned powdering step is compression-molded to obtain a green compact (Compression Molding Step). For example, an aluminum alloy powder heated to 250° C. to 300° C. is filled in a metal mold heated to 230° C. to 270° C. and compressed into a predetermined shape to obtain a green compact. Although the pressure of the compression molding is not particularly limited, it is usually preferably set to 0.5 ton/cm2 to 3.0 ton/cm2. Further, it is preferable to prepare a green compact having a relative density of 60% to 90%. Although the shape of the green compact is not particularly limited, it is preferably formed into a cylindrical shape or a disc shape, considering a subsequent extrusion step.

Next, the green compact obtained in the aforementioned compression molding step is hot-extruded to obtain an extruded material (Extrusion Step). The green compact is subjected to mechanical processing, such as, e.g., surfacing, as necessary, and then subjected to a degassing treatment, heating, and an extrusion step. The heating temperature of the green compact before extrusion is preferably set to 300° C. to 450° C. In extrusion, for example, the green compact is inserted into an extruding container, pressurized by an extrusion ram, and extruded from an extrusion die into, for example, a round bar shape. At this time, it is preferable that the extrusion container be previously heated to 300° C. to 400° C. By performing the hot-extrusion as described above, plastic deformation of the green compact progresses and an extruded article in which the aluminum alloy powder (particles) are bonded and integrated is obtained. At the time of the extrusion, the extrusion pressure is preferably set to 10 MPa to 25 MPa.

The extruded material 1 obtained in the extrusion step is configured such that an Al—Fe based intermetallic compound is contained in the extruded material and in the cross-sectional structure of the extruded material, the average circle equivalent diameter of the Al—Fe based intermetallic compound is within the range of 0.1 μm to 5.0 μm. Thus, the aluminum alloy extruded material of the present invention can be obtained.

The aluminum alloy extruded material (the aluminum alloy extruded material according to the present invention) obtained by the production method of the aluminum alloy extruded material according to the above-described present invention is an aluminum alloy extruded material consisting of Fe: 5.0 mass % to 9.0 mass %, V: 0.1 mass % to 3.0 mass %, Mo: 0.1 mass % to 3.0 mass %, Zr: 0.1 mass % to 2.0 mass %, Ti: 0.02 mass % to 2.0 mass %, and the balance being Al and inevitable impurities, wherein the aluminum alloy extruded material contains an Al—Fe based intermetallic compound, and wherein an average circle equivalent diameter of the Al—Fe based intermetallic compound is in a range of 0.1 μm to 3.0 μm in a cross-sectional structure of the aluminum alloy extruded material.

Note that the aluminum alloy extruded material according to the present invention is not limited to the aluminum alloy extruded material obtained by the aforementioned production method, but also includes those obtained by other production methods.

Next, the aluminum alloy powder and the production method of the aluminum alloy powder according to the present invention, and the composition of the “aluminum alloy” in the aluminum alloy extruded material and the production method of the aluminum alloy extruded material will be described in detail below. The aforementioned aluminum alloy is an aluminum alloy consisting of Fe: 5.0 mass % to 9.0 mass %, V: 0.1 mass % to 3.0 mass %, Mo: 0.1 mass % to 3.0 mass %, Zr: 0.1 mass % to 2.0 mass %, Ti: 0.02 mass % to 2.0 mass %, and the balance being Al and inevitable impurities.

The Fe (component) is an element that generates an Al—Fe based intermetallic compound having a high melting point and can improve mechanical properties (static strength, creep properties, etc.) in a high temperature range of 200° C. to 350° C. The Fe content rate in the aluminum alloy is set so as to fall within the range of 5.0 mass % to 9.0 mass %. When the Fe content rate is less than 5.0 mass %, the strength of the product, such as, e.g., aluminum alloy extruded material, is decreased. When the Fe content rate exceeds 9.0 mass %, the ductility of the product, such as, e.g., aluminum alloy extruded material, decreases. Therefore, excellent mechanical properties (static strength, creep properties, etc.) of a product, such as, e.g., aluminum alloy extruded material, at high temperature cannot be obtained. Among others, the Fe content rate in the aluminum alloy is preferably within the range of 7.0 mass % to 8.0 mass %.

The V (component) is an element that generates Al—Fe—V—Mo based intermetallic compound and can improve mechanical properties (static strength, creep properties, etc.) in a high temperature range of, for example, 200° C. to 350° C. The V content rate in the aluminum alloy is set so as to fall within the range of 0.1 mass % to 3.0 mass %. When the V content rate is less than 0.1 mass %, the strength of the product, such as, e.g., an aluminum alloy extruded material, is decreased. When the V content rate exceeds 3.0 mass %, the ductility of the product, such as, e.g., an aluminum alloy extruded material, decreases. Therefore, excellent mechanical properties (static strength, creep properties, etc.) of a product, such as, e.g., an aluminum alloy extruded material, at high temperature cannot be obtained. In particular, the V content rate in the aluminum alloy is preferably within the range of 1.0 mass % to 2.0 mass %.

The Mo (component) is an element that generates an Al—Fe—V—Mo based intermetallic compound and can improve mechanical properties (static strength, creep properties, etc.) in a high temperature range of, for example, 200° C. to 350° C. The Mo content rate in the aluminum alloy is set so as to fall within the range of 0.1 mass % to 3.0 mass %. When the Mo content rate is less than 0.1 mass %, the strength of the product, such as, e.g., an aluminum alloy extruded material, is decreased. When the Mo content rate exceeds 3.0 mass %, the ductility of the product, such as, e.g., an aluminum alloy extruded material, decreases. Therefore, excellent mechanical properties (static strength, creep properties, etc.) of a products, such as, e.g., an aluminum alloy extruded material, at high temperature cannot be obtained. In particular, the Mo content rate in the aluminum alloy is preferably within the range of 1.0 mass % to 2.0 mass %.

Zr (component) is an element which does not cause coarsening of an Al—Fe—V—Mo based intermetallic compound and can realize microcrystallization of intermetallic compounds. Further, when Zr is contained, it is possible to improve high temperature strength, and it is also possible to suppress self-diffusion of Al in the Al matrix, thereby improving creep properties. The Zr content rate in the aluminum alloy is set so as to fall within the range of 0.1 mass % to 2.0 mass %. When the Zr content rate is less than 0.1 mass %, there arises a problem that the effects of precipitation-strengthening and dispersion-strengthening cannot be exhibited. Further, when the Zr content rate exceeds 2.0 mass %, coarse intermetallic compounds including Zr are generated (see Comparative Example 9 to be described later), so that good mechanical properties cannot be obtained. In particular, the Zr content rate in the aluminum alloy is preferable within the range of 0.5 mass % to 1.5 mass %.

The Ti (component) has a role of forming an Al—(Ti, Zr) based intermetallic compound having an L12 structure with Al in cooperation with Zr. In addition, since the diffusion coefficient of Ti in the Al matrix is small, it is also possible to improve the creep properties. The Ti content rate in the aluminum alloy is set so as to fall within the range of 0.02 mass % to 2.0 mass %. When the Ti content rate is less than 0.02 mass %, there arises a problem that the effects of precipitation-strengthening and dispersion-strengthening cannot be exhibited. When the Ti content rate exceeds 2.0 mass %, the ductility decreases. Therefore, it is impossible to obtain aluminum alloy powder and an aluminum alloy extruded material excellent in mechanical properties (static strength, creep properties, etc.) at high temperature. In particular, the Ti content rate in the aluminum alloy is preferable within the range of 0.5 mass % to 1.0 mass %.

In the present invention, the aluminum alloy may have a configuration (composition) containing 0.0001 mass % to 0.03 mass % of B (boron). By setting the composition containing B at the aforementioned specific ratio, the crystal grain can be refined and the mechanical properties can be improved.

In the present invention, an Al—Fe based intermetallic compound is contained in the aluminum alloy powder or the aluminum alloy extruded material, and an average circle equivalent diameter of the Al—Fe based intermetallic compound is in the range of 0.1 μm to 3.0 μm in a cross-sectional structure of the aluminum alloy powder or the aluminum alloy extruded material. When the average circle equivalent diameter of the intermetallic compound is less than 0.1 μm, the effect of dispersion-strengthening cannot be exhibited. Further, when the average circle equivalent diameter of the intermetallic compound exceeds 3.0 μm, a coarse intermetallic compound is formed, which causes a problem that the mechanical properties are deteriorated since fractures occur with the coarse intermetallic compound as a starting point. Particularly, in the cross-sectional structure of the aluminum alloy powder or the aluminum alloy extruded material, the average circle equivalent diameter of the Al—Fe intermetallic compound is preferably within the range of 0.3 μm to 2.0 μm, particularly preferably within the range of 0.4 μm to 1.5 μm.

The Al—Fe based intermetallic compound is not particularly limited, but examples thereof include, e.g., an Al—Fe—V—Mo based intermetallic compound containing at least Al, Fe, V, and Mo. In the Al—Fe—V—Mo based intermetallic compound, it is preferably configured that the content rate of Al is 81.60 mass % to 92.37 mass %, the content rate of Fe is 2.58 mass % to 10.05 mass %, the content rate of V is 1.44 mass % to 4.39 mass %, the content rate of Mo is 2.45 mass % to 3.62 mass %. In this case, good mechanical properties can be obtained in a high temperature range of 200° C. or above.

Note that the circle equivalent diameter of the Al—Fe based intermetallic compound denotes a value converted to a diameter of a circle having the same area as the area of the Al—Fe based intermetallic compound in the SEM photograph (image) of the cross-section of the aluminum alloy powder or the aluminum alloy extruded material.

EXAMPLES

Next, specific examples of the present invention will be described, but the present invention is not particularly limited to those of these examples.

Example 1

An aluminum alloy containing Fe: 8.0 mass %, V: 2.0 mass %, Mo: 2.0 mass %, Zr: 1.0 mass %, Ti: 0.1 mass %, Al: 86.9 mass %, and inevitable impurities was heated to obtain an aluminum alloy molten metal of 1,000° C. Then, the aluminum alloy molten metal was atomized with a gas to quench-solidify it into powder. Thus, an aluminum alloy powder (aluminum alloy atomized powder) having an average particle diameter of 50 μm was obtained.

Next, the obtained aluminum alloy powder was preheated to a temperature of 280° C., the preheated aluminum alloy powder was filled in a mold heated at the same temperature of 280° C., and compression-molded with a pressure of 1. 5 ton/cm2. Thus, a columnar green compact (molded product) having a diameter of 210 mm and a length of 250 mm was obtained. Next, the obtained green compact was subjected to facing by a lathe to a diameter of 203 mm to obtain a green compact billet.

Next, the obtained billet was heated to 400° C., and this heated billet was inserted into an extrusion container maintained at 400° C. and having an inner diameter of 210 mm, and extruded at an extrusion ratio of 6.4 by an indirect extrusion method with a die having an inner diameter of 83 mm. Thus, an extruded material 1 was obtained (see FIG. 1).

Example 2

An extruded material 1 was obtained in the same manner as in Example 1 except that an aluminum alloy containing Fe: 8.0 mass %, V: 2.0 mass %, Mo: 2.0 mass %, Zr: 1.0 mass %, Ti: 0.5 mass %, Al: 86.5 mass %, and inevitable impurities was used as an aluminum alloy for forming an aluminum alloy molten metal.

Example 3

An extruded material 1 was obtained in the same manner as in Example 1 except that an aluminum alloy containing Fe: 8.0 mass %, V: 2.0 mass %, Mo: 2.0 mass %, Zr: 1.0 mass %, Ti: 1.0 mass %, Al: 86.0 mass %, and inevitable impurities was used as an aluminum alloy for forming an aluminum alloy molten metal.

Example 4

An extruded material 1 was obtained in the same manner as in Example 1 except that an aluminum alloy containing Fe: 8.0 mass %, V: 2.0 mass %, Mo: 2.0 mass %, Zr: 1.0 mass %, Ti: 2.0 mass %, Al: 85.0 mass %, and inevitable impurities was used as an aluminum alloy for forming an aluminum alloy molten metal.

Example 5

An extruded material 1 was obtained in the same manner as in Example 1 except that an aluminum alloy containing Fe: 8.0 mass %, V: 2.0 mass %, Mo: 2.0 mass %, Zr: 0.5 mass %, Ti: 1.0 mass %, Al: 86.5 mass %, and inevitable impurities was used as an aluminum alloy for forming an aluminum alloy molten metal.

Example 6

An extruded material 1 was obtained in the same manner as in Example 1 except that an aluminum alloy containing Fe: 8.0 mass %, V: 2.0 mass %, Mo: 2.0 mass %, Zr: 1.5 mass %, Ti: 1.0 mass %, Al: 85.5 mass %, and inevitable impurities was used as an aluminum alloy for forming an aluminum alloy molten metal.

Example 7

An extruded material 1 was obtained in the same manner as in Example 1 except that an aluminum alloy containing Fe: 8.0 mass %, V: 2.0 mass %, Mo: 0.5 mass %, Zr: 1.0 mass %, Ti: 1.0 mass %, Al: 87.5 mass %, and inevitable impurities was used as an aluminum alloy for forming an aluminum alloy molten metal.

Example 8

An extruded material 1 was obtained in the same manner as in Example 1 except that an aluminum alloy containing Fe: 8.0 mass %, V: 2.0 mass %, Mo: 1.5 mass %, Zr: 1.0 mass %, Ti: 1.0 mass %, Al: 86.5 mass %, and inevitable impurities was used as an aluminum alloy for forming an aluminum alloy molten metal.

Example 9

An extruded material 1 was obtained in the same manner as in Example 1 except that an aluminum alloy containing Fe: 8.0 mass %, V: 0.5 mass %, Mo: 2.0 mass %, Zr: 1.0 mass %, Ti: 1.0 mass %, Al: 87.5 mass %, and inevitable impurities was used as an aluminum alloy for forming an aluminum alloy molten metal.

Example 10

An extruded material 1 was obtained in the same manner as in Example 1 except that an aluminum alloy containing Fe: 8.0 mass %, V: 1.5 mass %, Mo: 2.0 mass %, Zr: 1.0 mass %, Ti: 1.0 mass %, Al: 86.5 mass %, and inevitable impurities was used as an aluminum alloy for forming an aluminum alloy molten metal.

Example 11

An extruded material 1 was obtained in the same manner as in Example 1 except that an aluminum alloy containing Fe: 6.0 mass %, V: 2.0 mass %, Mo: 2.0 mass %, Zr: 1.0 mass %, Ti: 1.0 mass %, Al: 88.0 mass %, and inevitable impurities was used as an aluminum alloy for forming an aluminum alloy molten metal.

Example 12

An extruded material 1 was obtained in the same manner as in Example 1 except that an aluminum alloy containing Fe: 7.0 mass %, V: 2.0 mass %, Mo: 2.0 mass %, Zr: 1.0 mass %, Ti: 1.0 mass %, Al: 87.0 mass %, and inevitable impurities was used as an aluminum alloy for forming an aluminum alloy molten metal.

Comparative Example 1

An extruded material 1 was obtained in the same manner as in Example 1 except that an aluminum alloy containing Fe: 8.0 mass %, V: 2.0 mass %, Mo: 2.0 mass %, Zr: 1.0 mass %, Al: 87.0 mass %, and inevitable impurities was used as an aluminum alloy for forming an aluminum alloy molten metal.

Comparative Example 2

An extruded material 1 was obtained in the same manner as in Example 1 except that an aluminum alloy containing Fe: 8.0 mass %, V: 2.0 mass %, Zr: 1.0 mass %, Si: 2.0 mass %, Cu: 0.13 mass %, Mg: 0.13 mass %, Al: 86.74 mass %, and inevitable impurities was used as an aluminum alloy for forming an aluminum alloy molten metal.

Comparative Example 3

An extruded material 1 was obtained in the same manner as in Example 1 except that an aluminum alloy containing Fe: 8.0 mass %, V: 2.0 mass %, Mo: 2.0 mass %, Zr: 1.0 mass %, Si: 2.0 mass %, Al: 85.0 mass %, and inevitable impurities was used as an aluminum alloy for forming an aluminum alloy molten metal.

Comparative Example 4

An extruded material 1 was obtained in the same manner as in Example 1 except that an aluminum alloy containing Fe: 8.0 mass %, V: 2.0 mass %, Mo: 2.0 mass %, Zr: 1.0 mass %, Mg: 1.0 mass %, Al: 86.0 mass %, and inevitable impurities was used as an aluminum alloy for forming an aluminum alloy molten metal.

Comparative Example 5

An extruded material 1 was obtained in the same manner as in Example 1 except that an aluminum alloy containing Fe: 8.0 mass %, V: 2.0 mass %, Mo: 2.0 mass %, Ti: 1.0 mass %, Al: 87.0 mass %, and inevitable impurities was used as an aluminum alloy for forming an aluminum alloy molten metal.

Comparative Example 6

An extruded material 1 was obtained in the same manner as in Example 1 except that an aluminum alloy containing Fe: 8.0 mass %, V: 2.0 mass %, Zr: 1.0 mass %, Ti: 1.0 mass %, Al: 88.0 mass %, and inevitable impurities was used as an aluminum alloy for forming an aluminum alloy molten metal.

Comparative Example 7

An extruded material 1 was obtained in the same manner as in Example 1 except that an aluminum alloy containing Fe: 8.0 mass %, Mo: 2.0 mass %, Zr: 1.0 mass %, Ti: 1.0 mass %, Al: 88.0 mass %, and inevitable impurities was used as an aluminum alloy for forming an aluminum alloy molten metal.

Comparative Example 8

An extruded material 1 was obtained in the same manner as in Example 1 except that an aluminum alloy containing V: 2.0 mass %, Mo: 2.0 mass %, Zr: 1.0 mass %, Ti: 1.0 mass %, Al: 94.0 mass %, and inevitable impurities was used as an aluminum alloy for forming an aluminum alloy molten metal.

Comparative Example 9

An extruded material 1 was obtained in the same manner as in Example 1 except that an aluminum alloy containing Fe: 8.0 mass %, V: 2.0 mass %, Mo: 2.0 mass %, Zr: 2.5 mass %, Ti: 1.0 mass %, Al: 84.5 mass %, and inevitable impurities was used as an aluminum alloy for forming an aluminum alloy molten metal.

Comparative Example 10

An extruded material 1 was obtained in the same manner as in Example 1 except that an aluminum alloy containing Fe: 8.0 mass %, V: 2.0 mass %, Mo: 4.0 mass %, Zr: 1.0 mass %, Ti: 1.0 mass %, Al: 84.0 mass %, and inevitable impurities was used as an aluminum alloy for forming an aluminum alloy molten metal.

Comparative Example 11

An extruded material 1 was obtained in the same manner as in Example 1 except that an aluminum alloy containing Fe: 6.0 mass %, V: 4.0 mass %, Mo: 2.0 mass %, Zr: 1.0 mass %, Ti: 1.0 mass %, Al: 86.0 mass %, and inevitable impurities was used as an aluminum alloy for forming an aluminum alloy molten metal.

Comparative Example 12

An extruded material 1 was obtained in the same manner as in Example 1 except that an aluminum alloy containing Fe: 10.0 mass %, V: 2.0 mass %, Mo: 2.0 mass %, Zr: 1.0 mass %, Ti: 1.0 mass %, Al: 84.0 mass %, and inevitable impurities was used as an aluminum alloy for forming an aluminum alloy molten metal.

TABLE 1 Comp. Comp. Comp. Comp. Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Alloy composition Fe (mass %) 8.0 8.0 8.0 8.0 8.0 8.0 8.0 8.0 V (mass %) 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 Mo (mass %) 2.0 2.0 2.0 2.0 2.0 — 2.0 2.0 Zr (mass %) 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 Ti (mass %) 0.1 0.5 1.0 2.0 — — — — Si (mass %) — — — — — 2.0 2.0 — Cu (mass %) — — — — — 0.13 — — Mg (mass %) — — — — — 0.13 — 1.0 Al (mass %) 86.9 86.5 86.0 85.0 87.0 86.74 85.0 86.0 Average circle equivalent 0.62 0.71 0.65 0.77 0.90 0.93 0.77 0.82 diameter of the intermetallic compound (μm) Evaluation Tensile strength (MPa) at 353/◯ 368/⊚ 400/⊚ 458/⊚ 340/X 270/X 283/X 340/X high temperature (260° C.) Fatigue strength (MPa) at 207/◯ 213/⊚ 219/⊚ 240/⊚ 201/Δ 158/X 169/X 201/Δ high temperature (260° C.) Creep rapture strength 212/◯ 220/⊚ 237/⊚ 260/⊚ 207/Δ 165/X 180/X 204/X (MPa) at high temperature (260° C.) Overall evaluation ◯ ⊚ ⊚ ⊚ X X X X

TABLE 2 Ex. 5 Ex. 6 Ex. 7 Ex. 8 Ex. 9 Ex. 10 Ex. 11 Ex. 12 Alloy composition Fe (mass %) 8.0 8.0 8.0 8.0 8.0 8.0 6.0 7.0 V (mass %) 2.0 2.0 2.0 2.0 0.5 1.5 2.0 2.0 Mo (mass %) 2.0 2.0 0.5 1.5 2.0 2.0 2.0 2.0 Zr (mass %) 0.5 1.5 1.0 1.0 1.0 1.0 1.0 1.0 Ti (mass %) 0.1 1.0 1.0 1.0 1.0 1.0 1.0 1.0 Si (mass %) — — — — — — — — Cu (mass %) — — — — — — — — Mg (mass %) — — — — — — — — Al (mass %) 86.5 85.5 87.5 86.5 87.5 86.5 88.0 87.0 Average circle equivalent 0.72 0.75 0.72 0.74 0.70 0.75 0.54 0.63 diameter of the intermetallic compound (μm) Evaluation Tensile strength (MPa) at 365/⊚ 430/⊚ 376/⊚ 420/⊚ 360/⊚ 424/⊚ 352/◯ 368/⊚ high temperature (260° C.) Fatigue strength (MPa) at 205/◯ 236/⊚ 205/◯ 233/⊚ 205/◯ 231/⊚ 205/◯ 208/◯ high temperature (260° C.) Creep rapture strength 216/◯ 250/⊚ 215/⊚ 228/⊚ 214/◯ 230/⊚ 210/◯ 222/⊚ (MPa) at high temperature (260° C.) Overall evaluation ◯ ⊚ ◯ ⊚ ◯ ⊚ ◯ ◯

TABLE 3 Comp. Comp. Comp. Comp. Comp. Comp. Comp. Comp. Ex. 5 Ex. 6 Ex. 7 Ex. 8 Ex. 9 Ex. 10 Ex. 11 Ex. 12 Alloy composition Fe (mass %) 8.0 8.0 8.0 — 8.0 8.0 6.0 10.0 V (mass %) 2.0 2.0 — 2.0 2.0 2.0 4.0 2.0 Mo (mass %) 2.0 — 2.0 2.0 2.0 4.0 2.0 2.0 Zr (mass %) — 1.0 1.0 1.0 2.5 1.0 1.0 1.0 Ti (mass %) 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 Si (mass %) — — — — — — — — Cu (mass %) — — — — — — — — Mg (mass %) — — — — — — — — Al (mass %) 87.0 88.0 88.0 94.0 84.5 84.0 86.0 84.0 Average circle equivalent 0.73 0.70 0.72 0.48 3.18 3.22 3.13 4.42 diameter of the intermetallic compound (μm) Evaluation Tensile strength (MPa) at 339/X 348/Δ 347/Δ 192/X 325/X 320/X 330/X 295/X high temperature (260° C.) Fatigue strength (MPa) at 182/X 198/X 192/X 105/X 178/X 172/X 178/X 165/X high temperature (260° C.) Creep rapture strength 197/X 208/Δ 203/X 117/X 196/X 184/X 192/X 172/X (MPa) at high temperature (260° C.) Overall evaluation X X X X X X X X

Each aluminum alloy extruded material (extruded product) obtained as described above was evaluated based on the following evaluation method. The results are shown in Tables 1 and 3. Note that in each element column of Tables 1 to 3, the symbol “−” indicates that it was a numerical value lower than the detection limit (0.005 mass %) (that is, no element was detected).

Further note that the “average circle equivalent diameter (μm) of the intermetallic compound” in Tables 1 to 3 means that the average circle equivalent diameter of an Al—Fe—V—Mo based intermetallic compound (intermetallic compound containing at least Al, Fe, V, and Mo) existing in the matrix of each aluminum alloy extruded material. This “average circle equivalent diameter (μm) of the intermetallic compound” was obtained as follows. From the central portion (intermediate bisecting position) of the obtained aluminum alloy extruded material (columnar article) in the L direction (longitudinal direction, i.e., axial direction), samples for tissue observation each having a size of 10 mm in length×10 mm in width×10 mm in thickness were cut into pieces. This sample piece was micro-polished using a cross section sample preparation apparatus (cross section polisher). Then, an SEM photograph (scanning electron microscope photograph) of this sample piece after the micro polishing was taken. From this photographic image, the average circle equivalent diameter (μm) of the intermetallic compound was determined (evaluated). An average circle equivalent diameter was calculated for 10 Al—Fe—V—Mo based intermetallic compounds existing in the field of view 1.5815 mm2 in the SEM photograph.

Evaluation Method of Tensile Strength at High Temperature

The obtained aluminum alloy extruded material (columnar article) was processed into a tensile test piece having a gauge distance of 20 mm and a parallel portion diameter of 4 mm. Then, the high temperature tensile strength (tensile strength at 260° C.) was measured by performing a high temperature tensile test of the tensile test piece. The high temperature tensile test was performed under the measurement environment of 260° C. after holding the high temperature tensile test piece 260° C. for 100 hours. The evaluation was made based on the following criteria.

(Criteria)

  • “⊚”: Tensile strength at 260° C. is 355 MPa or more
  • “◯”: Tensile strength at 260° C. is 350 MPa or more and less than 355 MPa
  • “Δ”: Tensile strength at 260° C. is 345 MPa or more and less than 350 MPa
  • “×”: Tensile strength at 260° C. is less than 345 MPa

Fatigue Test Method at High Temperature

The obtained aluminum alloy extruded material (columnar article) was processed into a fatigue tensile test piece having a gauge distance of 30 mm and a parallel portion diameter of 8 mm. Then, the high temperature fatigue strength (fatigue strength at 260° C.) was measured by performing a high temperature fatigue test of the tensile test piece. The high temperature fatigue test was performed by holding the fatigue test piece at 260° C. for 100 hours and then testing 500,000 times under the measurement environment of 260° C. at a repetition rate of 3,600 rpm. The evaluation was made based on the following criteria.

(Criteria)

  • “⊚”: Fatigue strength at 260° C. is 210 MPa or more
  • “◯”: Fatigue strength at 260° C. is 205 MPa or more and less than 210 MPa
  • “Δ”: Fatigue strength at 260° C. is 200 MPa or more and less than 205 MPa
  • “×”: Fatigue strength at 260° C. is less than 200 MPa

Creep Test Method at High Temperature

The obtained aluminum alloy extruded material (columnar article) was processed into a creep test piece having a gauge distance of 30 mm and a parallel portion diameter of 6 mm. Then, the high temperature creep properties (creep properties at 260° C.) was measured by performing a high temperature creep test of the creep test piece. The high temperature creep test was performed under the measurement environment of 260° C. after holding the creep test piece at 260° C. for 100 hours. The creep rupture strength under the conditions of the temperature of 260° C. and the rupture time of 300 hours was calculated and evaluated based on the following criteria.

(Criteria)

  • “⊚”: Creep strength at 260° C. is 215 MPa or more
  • “◯”: Creep strength at 260° C. is 210 MPa or more and less than 215 MPa
  • “Δ”: Creep rupture strength at 260° C. is 205 MPa or more and less than 210 MPa
  • “×”: Creep rupture strength at 260° C. is less than 205 MPa

As is apparent from the tables, the aluminum alloy extruded materials of Examples 1 to 12 according to the present invention were excellent in various mechanical properties at high temperature (260° C.)

On the other hand, the aluminum alloy extruded materials of Comparative Examples 1 to 12 deviating from the specified range of the present invention were inferior to the mechanical properties at high temperature (260° C.)

INDUSTRIAL APPLICABILITY

The aluminum alloy powder, and the aluminum alloy material formed using the aluminum alloy powder obtained by the production method of the present invention are excellent in mechanical properties at high temperature. Further, since the aluminum alloy extruded material according to the present invention and the aluminum alloy extruded material obtained by the production method of the present invention are excellent in mechanical properties at high temperature, it is suitably used as an internal combustion engine member (internal combustion engine parts) which is rotated at high speed under high temperature, such as turbocharger turbo compressor impeller used for an internal combustion engine of an automobile, etc.

The present application claims priority to Japanese Patent Application No. 2017-193269 filed on Oct. 3, 2017, the entire disclosure of which is incorporated herein by reference in its entirety.

It should be understood that the terms and expressions used herein are used for explanation and have no intention to be used to construe in a limited manner, do not eliminate any equivalents of features shown and mentioned herein, and allow various modifications falling within the claimed scope of the present invention. The present invention allows any design changes unless departing from its spirit within the scope of the claims.

DESCRIPTION OF REFERENCE SYMBOLS

  • 1: aluminum alloy extruded material (extruded product)

Claims

1. An aluminum alloy powder consisting of Fe: 5.0 mass % to 9.0 mass %, V: 0.1 mass % to 3.0 mass %, Mo: 0.1 mass % to 3.0 mass %, Zr: 0.1 mass % to 2.0 mass %, Ti: 0.02 mass % to 2.0 mass %, and the balance being Al and inevitable impurities,

wherein the aluminum alloy powder contains an Al—Fe based intermetallic compound, and
wherein an average circle equivalent diameter of the Al—Fe based intermetallic compound is in a range of 0.1 μm to 3.0 μm in a cross-sectional structure of the aluminum alloy powder.

2. The aluminum alloy powder as recited in claim 1, further consisting of 0.0001 mass % to 0.03 mass % of B.

3. A production method of an aluminum alloy powder, comprising:

quench-solidifying a molten metal of an aluminum alloy by an atomizing method into powder to obtain an aluminum alloy powder,
wherein the aluminum alloy consists of Fe: 5.0 mass % to 9.0 mass %, V: 0.1 mass % to 3.0 mass %, Mo: 0.1 mass % to 3.0 mass %, Zr: 0.1 mass % to 2.0 mass %, Ti: 0.02 mass % to 2.0 mass %, and the balance being Al and inevitable impurities.

4. An aluminum alloy extruded material consisting of Fe: 5.0 mass % to 9.0 mass %, V: 0.1 mass % to 3.0 mass %, Mo: 0.1 mass % to 3.0 mass %, Zr: 0.1 mass % to 2.0 mass %, Ti: 0.02 mass % to 2.0 mass %, and the balance being Al and inevitable impurities,

wherein the aluminum alloy extruded material contains an Al—Fe based intermetallic compound, and
wherein an average circle equivalent diameter of the Al—Fe based intermetallic compound is in a range of 0.1 μm to 3.0 μm in a cross-sectional structure of the aluminum alloy extruded material.

5. The aluminum alloy extruded material as recited in claim 4,

wherein the aluminum alloy extruded material further contains 0.0001 mass % to 0.03 mass % of B.

6. The aluminum alloy extruded material as recited in claim 4,

wherein the intermetallic compound is an Al—Fe—V—Mo based intermetallic compound containing at least Al, Fe, V, and Mo, and
wherein in the intermetallic compound, a content rate of Al is 81.60 mass % to 92.37 mass %, a content rate of Fe is 2.58 mass % to 10.05 mass %, a content rate of V is 1.44 mass % to 4.39 mass %, and a content rate of Mo is 2.45 mass % to 3.62 mass %.

7. The aluminum alloy extruded material as recited in claim 5,

wherein the intermetallic compound is an Al—Fe—V—Mo based intermetallic compound containing at least Al, Fe, V, and Mo, and
wherein in the intermetallic compound, a content rate of Al is 81.60 mass % to 92.37 mass %, a content rate of Fe is 2.58 mass % to 10.05 mass %, a content rate of V is 1.44 mass % to 4.39 mass %, and a content rate of Mo is 2.45 mass % to 3.62 mass %.

8. A production method of an aluminum alloy extruded material, comprising:

a compression molding step of compression molding the aluminum alloy powder recited in claim 1 to obtain a green compact; and
an extrusion step of hot extruding the green compact to obtain an extruded material,
wherein the extruded material contains an Al—Fe based intermetallic compound in the extruded material, and
wherein in a cross-sectional structure of the extruded material, an average circle equivalent diameter of the Al—Fe based intermetallic compound is in a range of 0.1 μm to 3.0 μm.

9. A production method of an aluminum alloy extruded material, comprising:

a compression molding step of compression molding the aluminum alloy powder recited in claim 2 to obtain a green compact; and
an extrusion step of hot extruding the green compact to obtain an extruded material,
wherein the extruded material contains an Al—Fe based intermetallic compound in the extruded material, and
wherein in a cross-sectional structure of the extruded material, an average circle equivalent diameter of the Al—Fe based intermetallic compound is in a range of 0.1 μm to 3.0 μm.
Patent History
Publication number: 20190100824
Type: Application
Filed: Oct 2, 2018
Publication Date: Apr 4, 2019
Applicant: SHOWA DENKO K.K. (Tokyo)
Inventor: Takuya ARAYAMA (Fukushima)
Application Number: 16/149,421
Classifications
International Classification: C22C 21/00 (20060101); C22C 1/04 (20060101); B22F 9/08 (20060101); B22F 3/20 (20060101);