Aluminum sintered member

Abstract

The purpose of the present invention is to provide an aluminum sintered member which is excellent in tensile strength, resistance to stress corrosion crack, resistance to welding, and fatigue strength.　The present invention provides an aluminum sintered member which is a sintered molded article of Al-Si-Mg-based alloy powder and pure aluminum powder or aluminum alloy powder except for Al-Si-Mg-based alloy as a main component, wherein the Al-Si-Mg-based alloy powder includes 10%-24% by mass of Si and 2%-7% by mass of Mg, and the balance includes Al and unavoidable impurities; the area ratio of the eutectic structure formed from the Al-Si-Mg-based alloy is 6%-30% in the metallic structure of the aluminum sintered member; and the porosity of the aluminum sintered member is 5% or less.

Description

Sintered aluminum parts

[0001] The present invention relates to an aluminum sintered member, and more particularly to an aluminum sintered member having excellent tensile strength, stress corrosion cracking resistance, weldability, and fatigue strength.

[0002] Sintered components made from metal powders are attracting attention as automotive components due to their high degree of freedom in shape and composition, their low material loss due to near-net forming, and the reduced number of processing steps. While such sintered components are sometimes used for complex-shaped parts such as bearings and small gears in automotive engine and drivetrain components, iron-based alloy powders are generally used as the metal powder for sintered components. In the case of sintered components made from aluminum powder, such as pure aluminum or aluminum alloys, the oxide film that forms on the surface is known to inhibit sintering, making it difficult to increase density and unsuitable for shaped components requiring high strength. Meanwhile, development of aluminum nitride powder and alumina powder for sintering is also progressing, but their machinability issues make them unsuitable for automotive components.

[0003] Additionally, additive manufacturing (AM) components obtained by forming metal powder using AM techniques are increasingly being used for automotive components. One AM molding method that has been developed involves selectively irradiating raw metal powder with a laser or electron beam as each layer is stacked, resulting in direct sintering. Another AM method, the binder jet method, involves solidifying metal powder by spraying a liquid binder from a nozzle onto the powder. While the binder jet method promises high productivity, it requires a sintering process after solidification. For the same reasons mentioned above, there are no practical examples of using aluminum powder as the raw material, and most applications have been with iron-based powder.

[0004] However, weight reduction is required for automobile parts, and development of aluminum applications continues. Aluminum alloy powders containing copper have been proposed as aluminum alloy powders for aluminum sintered parts (for example, JP 2009-7650 A).

[0005] However, it has been found that the sintered member using the aluminum alloy powder described in JP 2009-7650 A has insufficient strength for use as an automobile part, has problems with corrosion resistance, and may have insufficient weldability.

[0006] Automobiles are required to be more fuel efficient, and weight reduction is one way to improve fuel efficiency. To achieve this, the use of aluminum is expected to continue to increase. Furthermore, with the development of manufacturing methods, it is expected that an increasing number of parts will be made using components manufactured using sintering and additive manufacturing. To ensure the quality of automobiles, these components must be made even stronger, and sintered aluminum components are required to have performance such as stress corrosion cracking resistance. In particular, conventional sintered aluminum components have low strength and also have issues with stress corrosion cracking resistance and weldability. Therefore, an object of the present invention is to provide an aluminum sintered component that has excellent tensile strength, stress corrosion cracking resistance, weldability, and fatigue strength.

[0007] The present inventors have conducted extensive research to achieve the above object, and as a result have found that the above object can be achieved by using a raw material powder in which a predetermined Al-Si-Mg alloy powder is added to aluminum powder as the main component, and by controlling the area ratio of the eutectic structure of the Al-Si-Mg alloy in the aluminum sintered member and the porosity of the aluminum sintered member within predetermined ranges, thereby completing the present invention.

[0008] That is, the present invention provides an aluminum sintered member which is a sintered molded product of pure aluminum powder or aluminum alloy powder other than an Al-Si-Mg alloy as a main component and an Al-Si-Mg alloy powder, wherein the Al-Si-Mg alloy powder contains 10 to 24 mass % of Si and 2 to 7 mass % of Mg, with the remainder being Al and unavoidable impurities, and the area ratio of the eutectic structure formed of the Al-Si-Mg alloy in the metal structure of the aluminum sintered member is 6 to 30%, and the porosity of the aluminum sintered member is 5% or less.

[0009] FIG. 1 is an optical microscope photograph of a sample of the aluminum sintered member produced in Example 1.

[0010] Hereinafter, an aluminum sintered member according to one embodiment of the present invention will be described.

[0011] [Aluminum Sintered Member] One aspect of the present invention is an aluminum sintered member that is a sintered molded product of pure aluminum powder or aluminum alloy powder other than an Al-Si-Mg alloy as a main component and an Al-Si-Mg alloy powder, wherein the Al-Si-Mg alloy powder contains 10 to 24 mass% Si and 2 to 7 mass% Mg, with the balance being Al and unavoidable impurities (unavoidable impurities), and the metal structure of the aluminum sintered member has an area ratio of 6 to 30% of a eutectic structure formed by the Al-Si-Mg alloy, and the aluminum sintered member has a porosity of 5% or less. According to the present invention, an aluminum sintered member can be obtained that has excellent tensile strength, stress corrosion cracking resistance, weldability, and fatigue strength.

[0012] Specifically, the aluminum sintered member of this embodiment is an aluminum sintered member obtained by mixing and sintering pure aluminum powder or aluminum alloy powder other than an Al-Si-Mg alloy as a main component with an Al-Si-Mg alloy powder, wherein the Al-Si-Mg alloy powder contains 10 to 24 mass % Si and 2 to 7 mass % Mg, with the balance being Al and unavoidable impurities, and the area ratio of the eutectic structure formed of the Al-Si-Mg alloy in the metal structure of the aluminum sintered member is 6 to 30%, and the porosity of the aluminum sintered member is 5% or less.

[0013] (Raw Material Powder) The aluminum sintered member of this embodiment is manufactured using raw material powder containing pure aluminum powder or aluminum alloy powder other than Al—Si—Mg alloy as the main component, and Al—Si—Mg alloy powder.

[0014] (Pure aluminum powder) Pure aluminum powder is aluminum powder whose components are 99% by mass or more. The means for preparing the pure aluminum powder is not particularly limited. As the pure aluminum, for example, aluminum 1000 series materials such as JIS standard A1100 and A1200 can be used. Two or more types of pure aluminum powder may be used in combination.

[0015] (Aluminum alloy powder excluding Al-Si-Mg alloys) The aluminum alloy powder excluding Al-Si-Mg alloys is not particularly limited as long as it is other than the Al-Si-Mg alloys described below, but is preferably an aluminum alloy powder having an Al content of more than 50 mass%. Furthermore, although not particularly limited, it is preferable that the Si and Mg contents are each less than 2 mass%, and that the Mg content is greater than the Si content. The aluminum alloy powder preferably has an Al content of 80 mass% or more, more preferably 90 mass% or more, even more preferably 93 mass% or more, and even more preferably 95 mass% or more.

[0016] The aluminum alloy powder preferably contains less than 1 mass %, more preferably 0.5 mass % or less, of copper, which may impair stress corrosion cracking resistance and weldability.

[0017] The source of the aluminum alloy powder is not particularly limited. For example, aluminum 6000 series alloys such as JIS standards A6061, A6063, and A6101 can be used as the aluminum alloy. Aluminum 6000 series alloys are aluminum alloys to which Mg and Si are added, and have excellent strength and corrosion resistance. The use of aluminum 6000 series alloys can further improve the strength of aluminum sintered members. Two or more types of aluminum alloy powders may be used in combination.

[0018] Here, the term "major component" refers to a component that is contained in an amount exceeding 50% by mass of the raw material powder. The content of pure aluminum powder or aluminum alloy powder other than Al-Si-Mg alloy (also referred to as "aluminum powder") in the raw material powder of the aluminum sintered member of this embodiment is not particularly limited as long as it exceeds 50% by mass, but is preferably 70 to 94% by mass. This makes it possible to easily control the area ratio of the eutectic structure formed by the Al-Si-Mg alloy in the metal structure of the aluminum sintered member within a predetermined range. As a result, the effects of the present invention can be more effectively achieved. When two or more types of aluminum powder are used in combination, it is preferable that the total amount be within the above-mentioned range.

[0019] (Al—Si—Mg Alloy Powder) The Al—Si—Mg alloy powder contains 10 to 24 mass % of Si, 2 to 7 mass % of Mg, and the remainder being Al and unavoidable impurities.

[0020] A challenge in sintering aluminum powder is the presence of a strong oxide film on the surface of the aluminum powder, which prevents densification during the sintering process and results in insufficient strength for the sintered component. In the present embodiment, a high-density aluminum sintered component can be obtained by mixing an Al-Si-Mg alloy powder with pure aluminum powder or an aluminum alloy powder other than an Al-Si-Mg alloy, which is the main component, to promote liquid phase sintering. Furthermore, Mg was selected as the strengthening element because the addition of Cu increases susceptibility to weld cracking and stress corrosion cracking (making cracking more likely to occur). Furthermore, because the susceptibility to weld cracking and stress corrosion cracking increases with increasing Mg addition, an upper limit for the Mg content was specified.

[0021] (Silicon (Si): 10 to 24% by mass) If the silicon content is less than 10% by mass, sufficient liquid phase sintering will not occur, and densification will not be possible, resulting in insufficient strength. If the silicon content exceeds 24% by mass, the proportion of eutectic structures formed after sintering will be excessively large, resulting in a decrease in strength.

[0022] (Magnesium (Mg): 2 to 7 mass%) Magnesium has the effect of promoting liquid phase sintering, similar to silicon, and also reduces the oxide film present on the aluminum surface, promoting sintering of the aluminum. If the magnesium content is less than 2 mass%, the effect of reducing the oxide film is small and sufficient liquid phase sintering does not occur, resulting in failure to densify and insufficient strength being obtained. On the other hand, if the magnesium content exceeds 7 mass%, there is a problem of an increased risk of stress corrosion cracking.

[0023] (Aluminum (Al) and inevitable impurities: balance) The balance of the Al-Si-Mg alloy powder, excluding Si and Mg, is Al and inevitable impurities. The inevitable impurities refer to those present in the raw materials or those inevitably mixed in during the manufacturing process. Although inevitable impurities are essentially unnecessary, they are tolerated because they are present in trace amounts and do not affect the properties of the Al-Si-Mg alloy powder or the aluminum sintered member made therefrom. The content of inevitable impurities is preferably less than 0.1% by mass, and more preferably less than 0.01% by mass, of the Al-Si-Mg alloy powder.

[0024] The Al-Si-Mg alloy powder preferably contains less than 1 mass %, more preferably 0.5 mass % or less, still more preferably 0.1 mass % or less, and most preferably 0 mass % (no copper content), which may impair stress corrosion cracking resistance and weldability.

[0025] The melting point of the Al-Si-Mg alloy powder is preferably lower than that of the primary component, pure aluminum powder, or aluminum alloy powder other than the Al-Si-Mg alloy. This facilitates liquid phase sintering, enabling a high-density sintered aluminum component to be obtained more efficiently. The melting point of the Al-Si-Mg alloy powder is preferably, for example, approximately 30 to 70°C lower than that of the primary component. A melting point difference within the above range allows for a low porosity and a dense sintered aluminum component to be obtained more efficiently. The melting point of the Al-Si-Mg alloy powder may be, for example, approximately 590 to 630°C. The melting point of the Al-Si-Mg alloy powder can be controlled by adjusting the composition of the Al-Si-Mg alloy. For example, increasing the Si or Mg content tends to increase the melting point. The melting point of the Al-Si-Mg alloy powder can be estimated from a phase diagram.

[0026] The content of the Al-Si-Mg alloy powder in the raw material powder of the aluminum sintered member of this embodiment is not particularly limited as long as it is less than 50 mass%, but is preferably 6 to 30 mass%. This makes it possible to easily control the area ratio of the eutectic structure formed by the Al-Si-Mg alloy in the metal structure of the aluminum sintered member within a predetermined range. As a result, the effects of the present invention can be more effectively achieved. When two or more types of Al-Si-Mg alloy powders are used in combination, it is preferable that the total amount be within the above range.

[0027] The total content of aluminum powder (pure aluminum powder or aluminum alloy powder other than Al-Si-Mg alloy) and Al-Si-Mg alloy powder in the raw material powder of the aluminum sintered member of this embodiment is not particularly limited, but is preferably 90 mass % or more, more preferably 95 mass % or more, and even more preferably 98 mass % or more, based on the total amount of raw material powder. 100 mass % is most preferable. This allows the effects of the present invention to be more significantly achieved.

[0028] Furthermore, as automotive parts have issues with stress corrosion cracking and welding, it is preferable that the raw material powder for the aluminum sintered member of this embodiment does not contain components that contain elements such as copper that impair corrosion resistance or weldability.

[0029] In a preferred embodiment of the present invention, the main component of the raw material powder is pure aluminum powder, and the Al-Si-Mg alloy powder contains 10 to 24 mass % of Si and 3 to 7 mass % of Mg, with the remainder being Al and unavoidable impurities. With this configuration, the effects of the present invention can be more significantly achieved.

[0030] In another preferred embodiment of the present invention, the main component of the raw material powder is aluminum alloy powder, and the Al-Si-Mg alloy powder contains 10 to 24 mass% Si and 2 to 7 mass% Mg, with the remainder being Al and unavoidable impurities. This configuration can more significantly achieve the effects of the present invention. In particular, the tensile strength and fatigue strength can be further improved. In this case, if the aluminum alloy powder is aluminum 6000 series alloy powder, the resulting aluminum sintered member will be even denser, and the effects of the present invention can be more significantly achieved.

[0031] (Elemental Composition of Sintered Aluminum Member) The elemental composition of the sintered aluminum member according to this embodiment can be the same as the elemental composition of the mixed powder before sintering and compacting.

[0032] (Area ratio of eutectic structure formed by Al-Si-Mg alloy powder) In the aluminum sintered member according to this embodiment, the area ratio of the eutectic structure formed by the Al-Si-Mg alloy powder is 6 to 30%. If the area ratio of the eutectic structure is less than 6%, sufficient liquid phase sintering is not performed, and densification is not achieved, resulting in insufficient strength. If the area ratio of the eutectic structure exceeds 30%, the eutectic structure becomes easily embrittled, making it impossible to achieve sufficient strength. The area ratio of the eutectic structure is preferably 6 to 24%. The area ratio of the eutectic structure can be controlled by the content of the Al-Si-Mg alloy powder. The area ratio of the eutectic structure can be determined by the method described in the examples below.

[0033] (Porosity of Aluminum Sintered Member) The aluminum sintered member according to this embodiment has a porosity of 5% or less. If the porosity exceeds 5%, the sintered aluminum member will not be densified, resulting in insufficient tensile strength. Furthermore, since the pores tend to become the starting point for fatigue failure, sufficient fatigue strength will not be obtained. The porosity of the aluminum sintered member is preferably 4% or less. While the lower limit of the porosity is not particularly limited, it is, for example, 0.5% or more, and preferably 1% or more. Within the above range, the effects of the present invention can be more significantly achieved. The porosity of the aluminum sintered member can be determined by the method described in the Examples below. The porosity of the aluminum sintered member can be controlled, for example, by adjusting the type of aluminum powder used as the raw material, the composition and content of the Al-Si-Mg alloy powder, and the pressure, temperature, and time during sintering.

[0034] (Filling rate of sintered aluminum member) As described in the examples below, the filling rate of the sintered aluminum member is the proportion of the portion other than the pores. Therefore, from the same viewpoint as above, the filling rate of the sintered aluminum member according to this embodiment is 95% or more, for example, 96% or more. The upper limit of the filling rate is not particularly limited, but is, for example, 99.5% or less, for example, 99% or less.

[0035] (Method for manufacturing sintered aluminum member) The method for manufacturing the sintered aluminum member of this embodiment is not particularly limited. For example, a method including a mixing step of mixing pure aluminum powder or aluminum alloy powder other than an Al-Si-Mg alloy as a main component with an Al-Si-Mg alloy powder to obtain a mixed powder, and a sintering and molding step of sintering and molding the mixed powder can be suitably used. By this method, the sintered aluminum member of this embodiment can be easily obtained.

[0036] (Mixing Step) In the mixing step, pure aluminum powder or aluminum alloy powder excluding Al-Si-Mg alloy as the main component is mixed with Al-Si-Mg alloy powder to obtain a mixed powder.

[0037] As a mixing means, a known method can be appropriately adopted, for example, mixing using a mortar, a dry ball mill, a dynamic mill, a bead mill, a jet mill, a hammer mill, a disk mill, or a pin mill, and among these, mixing using a dry ball mill is preferred.

[0038] The mixing conditions are not particularly limited, but the rotation speed is preferably 400 to 700 rpm, and the mixing time is preferably 30 to 60 minutes.

[0039] (Sintering and forming process) In the sintering and forming process, the mixed powder obtained in the mixing process is sintered and formed. This solidifies the mixed powder, resulting in an aluminum sintered member. The sintering and forming is preferably carried out in a vacuum, for example, using a vacuum hot press. The conditions for sintering and forming are not particularly limited. For example, the pressure during sintering and forming is preferably 20 to 40 MPa. The temperature is preferably 500 to 580°C. The time is preferably 20 to 80 minutes. This allows for efficient production of an aluminum sintered member having a predetermined eutectic structure area ratio and a predetermined porosity.

[0040] The aluminum sintered member of this embodiment is lightweight, has high strength, and has excellent stress corrosion cracking resistance and welding resistance, and therefore can be suitably used for, but is not particularly limited to, automobile engine parts and drive train parts.

[0041] The following embodiments are also included within the scope of the present invention: an aluminum sintered part according to claim 1 having the features of claim 2; an aluminum sintered part according to claim 1 having the features of claim 3; an aluminum sintered part according to claim 1 or 3 having the features of claim 4; and a method for manufacturing an aluminum sintered part according to any one of claims 1 to 4 having the features of claim 5.

[0042] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0043] (Examples 1 to 8, Comparative Examples 1 to 8) Pure aluminum powder or aluminum alloy powder shown in Table 1 below was mixed with Al-Si-Mg alloy powder having the composition shown in Table 1 below in a dry ball mill (mixing conditions: rotation speed 550 rpm, time 45 minutes), and the mixed powder was solidified by a sintering process to obtain a sintered aluminum member. Sintering was performed using a vacuum hot press under a sintering pressure of 30 MPa at a sintering temperature of 540°C for 50 minutes.

[0044] In Table 1 below, the composition of the Al-Si-Mg alloy powder contains Si and Mg in the amounts shown in the table, with the remainder being Al and unavoidable impurities. The melting points of the Al-Si-Mg alloy powders are values ​​estimated from a phase diagram. In Comparative Example 7, instead of the Al-Si-Mg alloy powder, an Al-Cu alloy powder containing 5 mass% Cu, with the remainder being Al and unavoidable impurities, was used. In Comparative Example 8, instead of the Al-Si-Mg alloy powder, an Al-Mg alloy powder containing 5 mass% Mg, with the remainder being Al and unavoidable impurities was used.

[0045] (Measurement of area ratio, porosity and filling rate of eutectic structure formed from Al-Si-Mg alloy) For samples cut out from the aluminum sintered members produced in each of the examples and comparative examples, the area ratio of the eutectic structure formed from the Al-Si-Mg alloy (eutectic structure area ratio), the area ratio of voids in the aluminum sintered member (porosity) and the filling rate of the aluminum sintered member were measured by the following methods.

[0046] First, the sample was cut into small pieces to prepare a specimen for measurement. The cross section of the sample was mirror-polished, etched with nital, and an image was taken with an optical microscope. Next, a brightness threshold was set for the image so that the eutectic structure could be identified, and a binarization process was performed to measure the area of ​​the eutectic structure. The ratio of the area of ​​the eutectic structure included in this range to the total area within a range from the surface to 100 μm in the depth direction was calculated as a percentage. The porosity was then calculated as a percentage using the same method, with the area ratio being the same. The filling rate of the aluminum sintered member was calculated as the ratio of the area of ​​the portion other than the pores in the above porosity measurement. The results are shown in Table 1 below.

[0047] Figure 1 shows an optical microscope photograph of the sample of the sintered aluminum member produced in Example 1. As shown in Figure 1, the metal structure of the sintered aluminum member of this example is confirmed to have a eutectic structure (white areas) formed of an Al-Si-Mg alloy and voids (black areas) in the α-Al phase.

[0048] (Tensile strength) For samples cut out from the aluminum sintered members produced in each example and comparative example, a tensile test was carried out based on JIS Z 2241:2011 to determine the tensile strength. The results are shown in Table 1 below. A sample having a tensile strength of 90 MPa or more can be suitably used.

[0049] (Stress corrosion cracking resistance (SCC)) A stress corrosion cracking test was carried out on samples cut out from the aluminum sintered members produced in each of the examples and comparative examples. The stress corrosion cracking test involved evaluation of the corrosive environment under stress load based on JIS H 8711:2000. The results are shown in Table 1 below. A test in which no corrosion cracking occurred within the specified time (1000 hours) was evaluated as OK, and a test in which corrosion cracking occurred was evaluated as NG.

[0050] (Welding resistance) Two samples were cut out from the aluminum sintered members produced in each example and comparative example, and welded together using a MIG welding method to obtain a welded material. A tensile test was conducted on a test piece cut out from this welded material. The tensile test was conducted based on JIS H 8711:2000. The results are shown in Table 1 below. If the tensile strength of the welded material was 90% or more of the tensile strength of the base material (the aluminum sintered member before welding), it was evaluated as OK, and if it was less than 90%, it was evaluated as NG.

[0051] (Fatigue Strength) Samples cut out from the aluminum sintered members produced in each Example and Comparative Example were subjected to a rotating bending fatigue test in accordance with JIS Z 2273:1978. The results are shown in Table 1 below. The rotating bending fatigue strength was expressed as a relative value when the rotating bending fatigue strength of the aluminum sintered member of Example 1 was set to 1.0. A rotating bending fatigue strength of 0.8 or more was suitable for use.

[0052] In Table 1, the overall judgment was that the specimen was OK if all of the tensile strength, stress corrosion cracking resistance, weldability, and fatigue strength were suitable or OK, and NG if they were not.

[0053]

[0054] As can be seen from Table 1, the aluminum sintered members of Examples 1 to 8, which use predetermined Al-Si-Mg alloy powders and have eutectic structure area ratios and porosities within predetermined ranges, are excellent in tensile strength, stress corrosion cracking resistance, weldability, and fatigue strength.

[0055] On the other hand, in Comparative Examples 1 to 8, in which the composition of the Al-Si-Mg alloy powder, the area ratio of the eutectic structure, or the porosity was outside the specified range, it was found that sintered parts excellent in all of tensile strength, stress corrosion cracking resistance, weldability, and fatigue strength could not be obtained.

[0056] Although the present invention has been described above with reference to some embodiments and examples, the present invention is not limited to these and various modifications are possible within the scope of the gist of the present invention.

[0057] For example, the configurations described in the above-described embodiments and examples are not limited to each embodiment or example, and for example, the composition of each embodiment or the detailed conditions for manufacturing can be changed, or the configurations of each embodiment or example can be combined in a manner other than the above-described embodiments or examples.

Claims

1. An aluminum sintered member which is a sintered molded product of pure aluminum powder or aluminum alloy powder other than an Al-Si-Mg alloy as a main component and an Al-Si-Mg alloy powder, the Al—Si—Mg alloy powder contains 10 to 24 mass % of Si and 2 to 7 mass % of Mg, with the remainder being Al and unavoidable impurities; In the metal structure of the aluminum sintered member, the area ratio of a eutectic structure formed of the Al-Si-Mg alloy is 6 to 30%, The sintered aluminum member has a porosity of 5% or less.

2. 2. The aluminum sintered member according to claim 1, wherein the main component is the pure aluminum powder, and the Al-Si-Mg alloy powder contains 10 to 24 mass% of Si and 3 to 7 mass% of Mg, with the remainder being Al and unavoidable impurities.

3. The aluminum sintered member according to claim 1 , wherein the main component is the aluminum alloy powder.

4. 4. The aluminum sintered member according to claim 3, wherein the aluminum alloy powder is an aluminum 6000 series alloy powder.

5. The method for producing an aluminum sintered member according to any one of claims 1 to 4, a mixing step of mixing the pure aluminum powder or aluminum alloy powder other than an Al—Si—Mg alloy as the main component with the Al—Si—Mg alloy powder to obtain a mixed powder; and a sintering and compacting step of sintering and compacting the mixed powder.

6. 2. The aluminum sintered member according to claim 1, wherein the Mg content in the Al-Si-Mg alloy powder is 2 to 3 mass %.

7. 2. The aluminum sintered member according to claim 1, wherein the aluminum sintered member is a sintered molded product sintered at a sintering temperature of 540°C or less.

8. 4. The aluminum sintered member according to claim 3, wherein the aluminum alloy powder contains Mg and Si.

9. 2. The aluminum sintered member according to claim 1, wherein the content of the Al-Si-Mg alloy powder in the raw material powder of the aluminum sintered member is 15 to 30 mass %.

10. 2. The aluminum sintered member according to claim 1, wherein the pure aluminum powder and the aluminum alloy powder as the main components do not contain Cu.