Aluminum alloy powder sintered body

Abstract

To provide an aluminum alloy powder sintered body that can stably obtain high mechanical properties and thermal conductivity. [Solution] The precipitate alloy phase includes an aluminum precipitate alloy phase, and the thickness of the oxide film formed on the precipitate alloy phase when the precipitate alloy phase is exposed to air is in the range of 0.5 nm to 10 μm. It is preferable that the thermal conductivity is 195 W / (m·K) or higher. It is preferable that the precipitate alloy phase contains aluminum and a eutectic element.

Description

Technical Field

[0001] This invention relates to an aluminum alloy powder sintered body obtained by sintering a mixed powder of aluminum powder and metal oxide powder or an aluminum alloy powder.

Background Art

[0002] Aluminum (Al) is a non-ferrous metal useful in industry due to its light weight, high specific strength, and good electrical and thermal conductivity. However, it is a typical metal with poor sinterability and has the problem that it is difficult to achieve sufficient densification. If densification cannot be achieved, it is difficult to obtain strength, and the thermal conductivity also decreases, so it is difficult to put sintered products that can fully utilize its characteristics on the market.

[0003] Here, it is known that the sinterability of Al powder can be improved by adding different elements. For example, an alloy standard known as the A4000 series is obtained by adding silicon (Si) to Al, and an alloy standard known as the A6000 series is obtained by adding magnesium (Mg) in addition to Si. Since Al-Si has a eutectic composition, the liquidus line is lowered, and a method of promoting the occurrence of a liquid phase to stably proceed with sintering is adopted.

[0004] For example, in Patent Document 1, it is reported that a compacted sintered body having an Al-Si-Mg-Sn alloy composition reaches 98% or more of the theoretical density, has a tensile strength of 130 MPa or more, and a thermal conductivity of 200 W / (m·K) or more. In addition, since the addition of Si also has the effect of reducing solidification cracking, complex-shaped shaped products by the Laser Power Bed Fusion (L-PBF) method are also becoming known.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] Incidentally, the aforementioned aluminum alloy powder sintered bodies are being explored for use in a variety of applications, and further improvements in mechanical strength, electrical conductivity, and thermal conductivity are required to ensure stable use even in harsh environments.

[0007] The present invention has been made in view of the circumstances described above, and aims to provide an aluminum alloy powder sintered body that can stably obtain high mechanical properties, electrical conductivity, and thermal conductivity. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the present inventors conducted diligent research and found that in aluminum alloy powder sintered bodies, a precipitated alloy phase containing aluminum may precipitate in the aluminum matrix, and that by defining the state of this precipitated alloy phase, mechanical properties and thermal conductivity can be improved.

[0009] The present invention is based on the above-mentioned findings, and the aluminum alloy powder sintered body of embodiment 1 of the present invention includes a precipitated alloy phase containing aluminum, and the thickness of the oxide film formed on the precipitated alloy phase when the precipitated alloy phase is exposed to air is 0.5 nm or more. 6.2nm or less Includes precipitated alloy phases within the range Furthermore, the precipitated alloy phase contains rare earth metal elements, and the total content of the rare earth metal elements in the sintered body is in the range of 0.1 mass% to 5.0 mass%. It is characterized by the following.

[0010] According to the aluminum alloy powder sintered body of embodiment 1 of the present invention, when the precipitated alloy phase is exposed to air, the thickness of the oxide film formed on the precipitated alloy phase is 0.5 nm or more. 6.2nm or less Since it contains a precipitated alloy phase within a specified range, the precipitated alloy phase remains stable without oxidation inside the sintered body, which is not exposed to the atmosphere, and the penetration of oxygen into the interior is suppressed, allowing for stable and high mechanical properties and thermal conductivity to be obtained. Furthermore, since the precipitated alloy phase contains rare earth metal elements, the thermal conductivity of the aluminum body is ensured, and high mechanical properties and thermal conductivity can be reliably obtained. Furthermore, since the content of the aforementioned rare earth metal elements in the entire sintered body is within the range of 0.1 mass% to 5.0 mass%, an appropriate amount of liquid phase is generated during sintering, ensuring reliable densification and excellent shape stability.

[0011] The aluminum alloy powder sintered body according to aspect 2 of the present invention is characterized in that the thermal conductivity is 195 W / (m·K) or higher.

[0012] According to the aluminum alloy powder sintered body of aspect 2 of the present invention, the thermal conductivity is set to 195 W / (m·K) or higher, thus ensuring high thermal conductivity.

[0013] The aluminum alloy powder sintered body of embodiment 3 of the present invention is characterized in that, in the aluminum alloy powder sintered body of embodiment 1 or embodiment 2 of the present invention, the precipitated alloy phase contains aluminum and a eutectic element.

[0014] According to the aluminum alloy powder sintered body of embodiment 3 of the present invention, since the precipitated alloy phase contains aluminum and eutectic elements, it is easy to densify during sintering, and high mechanical properties and thermal conductivity can be reliably obtained.

[0019] The aluminum alloy powder sintered body of embodiment 6 of the present invention is characterized in that, in the aluminum alloy powder sintered body of embodiment 4 or embodiment 5 of the present invention, the rare earth metal element is one or more selected from lanthanum, cerium, praseodymium, neodymium, europium, samarium, terbium, gadolinium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium.

[0020] According to the aluminum alloy powder sintered body of embodiment 6 of the present invention, the rare earth metal element is selected from one or more of the following: lanthanum, cerium, praseodymium, neodymium, europium, samarium, terbium, gadolinium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium. This ensures the thermal conductivity of the aluminum body and reliably provides high mechanical properties and thermal conductivity.

[0021] The aluminum alloy powder sintered body of Aspect 7 of the present invention is the aluminum alloy powder sintered body of Aspect 4 or Aspect 5 of the present invention, wherein the rare earth metal element is one or more selected from praseodymium, neodymium, europium, samarium, terbium, gadolinium, dysprosium, holmium, thulium, ytterbium, lutetium.

[0022] According to the aluminum alloy powder sintered body of Aspect 7 of the present invention, since the rare earth metal element is one or more selected from praseodymium, neodymium, europium, samarium, terbium, gadolinium, dysprosium, holmium, thulium, ytterbium, lutetium, the thermal conductivity of the aluminum main body is ensured, and high mechanical properties and thermal conductivity can be surely obtained.

Effect of the Invention

[0023] According to the present invention, it is possible to provide an aluminum alloy powder sintered body capable of stably obtaining high mechanical properties and thermal conductivity.

Brief Description of the Drawings

[0024] [Figure 1] It is an explanatory drawing showing an example of the cross-sectional structure of the aluminum alloy powder sintered body which is an embodiment of the present invention. [Figure 2] It is a cross-sectional observation photograph of the aluminum alloy powder sintered body of Test No. 1. [Figure 3] It is a cross-sectional observation photograph of the aluminum alloy powder sintered body of Test No. 2. [Figure 4] It is a cross-sectional observation photograph of the aluminum alloy powder sintered body of Test No. 3. [Figure 5] It is a cross-sectional observation photograph of the aluminum alloy powder sintered body of Test No. 4. [Figure 6] It is a cross-sectional observation photograph of the aluminum alloy powder sintered body of Test No. 5. [Figure 7](a) is an observation photograph of the precipitated alloy phase and the oxide film on its surface of the aluminum alloy powder sintered body of Test No. 1, and (b) is the EDS spectral intensity of oxygen extracted from the position indicated by the arrow in the photograph. [Figure 8] (a) is an observation photograph of the precipitated alloy phase and the oxide film on its surface of the aluminum alloy powder sintered body from test No. 2, and (b) is the EDS spectral intensity of oxygen extracted from the position indicated by the arrow in the photograph. [Figure 9] (a) is an observation photograph of the precipitated alloy phase and the oxide film on its surface of the aluminum alloy powder sintered body from test No. 3, and (b) is the EDS spectral intensity of oxygen extracted from the position indicated by the arrow in the photograph. [Figure 10] (a) is an observation photograph of the precipitated alloy phase and the oxide film on its surface of the aluminum alloy powder sintered body from test No. 4, and (b) is the EDS spectral intensity of oxygen extracted from the position indicated by the arrow in the photograph. [Figure 11] (a) is an observation photograph of the precipitated alloy phase and the oxide film on its surface of the aluminum alloy powder sintered body of test No. 5, and (b) is the EDS spectral intensity of oxygen extracted from the position indicated by the arrow in the photograph. [Figure 12] This graph shows the correlation between the tensile strength and elongation of the aluminum alloy powder sintered body from test No. 1. [Figure 13] This graph shows the correlation between tensile strength and elongation of the aluminum alloy powder sintered body from test No. 2. [Figure 14] This graph shows the correlation between tensile strength and elongation of the aluminum alloy powder sintered body from test No. 3. [Figure 15] This graph shows the correlation between tensile strength and elongation of the aluminum alloy powder sintered body from test No. 4. [Figure 16] This graph shows the correlation between tensile strength and elongation of the aluminum alloy powder sintered body in test No. 5. [Modes for carrying out the invention]

[0025] The following describes an embodiment of the present invention, an aluminum alloy powder sintered body, with reference to the attached drawings. The embodiments described below are provided specifically to better illustrate the spirit of the invention and do not limit the present invention unless otherwise specified.

[0026] As shown in Figure 1, in the aluminum alloy powder sintered body 10, which is an embodiment of the present invention, the structure is such that an aluminum precipitated alloy phase 12 is dispersed in an aluminum matrix phase 11.

[0027] Furthermore, in the aluminum alloy powder sintered body 10 of this embodiment, the precipitated alloy phase includes an oxide film thickness t formed on the precipitated alloy phase 12 when the precipitated alloy phase 12 is exposed to the atmosphere, wherein the thickness t of the oxide film formed on the precipitated alloy phase 12 is in the range of 0.5 nm to 10 μm. The thickness t of the oxide film formed on the precipitated alloy phase 12 when exposed to air is measured by milling the aluminum alloy powder sintered body 10 in an inert gas atmosphere chamber to expose the precipitated alloy phase 12, then opening the chamber to the atmosphere, cutting out a portion of the milled surface of the observation sample using a focused ion beam processing method, and observing the thickness of the oxide film formed on the surface of the precipitated alloy phase 12 with a high-angle annular dark-field scanning transmission electron microscope (HAADF-STEM).

[0028] Here, if the thickness t of the oxide film formed on the precipitated alloy phase 12 when exposed to air is 0.5 nm or more, then when not exposed to air, it exists stably as a metal (alloy) rather than an oxide within the structure of the aluminum alloy powder sintered body 10, resulting in excellent mechanical properties. On the other hand, if the thickness t of the oxide film formed on the precipitated alloy phase 12 when exposed to air is 10 μm or less, then the penetration of oxygen into the interior is suppressed, and the properties remain stable even when used in an air atmosphere.

[0029] Furthermore, when the precipitated alloy phase 12 is exposed to air at room temperature, the thickness t of the oxide film formed on the precipitated alloy phase 12 is preferably 0.5 nm or more, and more preferably 1 nm or more. Furthermore, the thickness t of the oxide film formed on the precipitated alloy phase 12 when the precipitated alloy phase 12 is exposed to air at room temperature is preferably 1 μm or less, and more preferably 0.1 μm or less.

[0030] In this embodiment, the aluminum alloy powder sintered body 10 preferably has a tensile strength of 40 MPa or more. If the tensile strength is 40 MPa or higher, even a sintered body will have the same strength as rolled or extruded materials, and can be used in a variety of applications.

[0031] Furthermore, in the aluminum alloy powder sintered body 10 of this embodiment, it is preferable that the thermal conductivity is 195 W / (m·K) or higher. If the thermal conductivity is 195 W / (m·K) or higher, it can be suitably used as a component material for heat exchangers such as heat sinks. Furthermore, the thermal conductivity of the aluminum alloy powder sintered body 10 is more preferably 200 W / (m·K) or higher, and even more preferably 210 W / (m·K) or higher. There is no particular upper limit to the thermal conductivity of the aluminum alloy powder sintered body 10, but it is substantially less than or equal to 238 W / (m·K), which is the thermal conductivity of pure aluminum.

[0032] Furthermore, in the aluminum alloy powder sintered body 10 of this embodiment, it is preferable that the precipitated alloy phase 12 contains aluminum and eutectic elements. Examples of eutectic elements include Si, Cu, Mg, Zn, and rare earth elements. In aluminum alloys containing these eutectic elements, the liquidus temperature is lower, resulting in sufficient liquid phase formation during sintering. This densifies the aluminum alloy powder sintered body 10, further improving its mechanical properties and thermal conductivity.

[0033] The preferred content of eutectic elements will vary depending on the specific eutectic element. For example, in the case of Si, it is preferably in the range of 0 to 13.5 mass%; in the case of Cu, it is preferably in the range of 0 to 5.0 mass%; in the case of Mg, it is preferably in the range of 0 to 3.0 mass%; and in the case of Zn, it is preferably in the range of 0 to 7.0 mass%.

[0034] In this embodiment, in the aluminum alloy powder sintered body 10, it is preferable that the precipitated alloy phase contains rare earth metal elements. Since rare earth metal elements have an atomic weight approximately five times greater than aluminum, the atomic ratio of the added element is small compared to the weight ratio. Therefore, the liquid phase temperature can be lowered without impairing the properties of aluminum (e.g., thermal conductivity), and a sufficient liquid phase is formed during sintering. This densifies the aluminum alloy powder sintered body 10, further improving its mechanical properties and thermal conductivity.

[0035] The preferred content of rare earth metal elements is within the range of 0.1 mass% to 5.0 mass%. If the content of rare earth metal elements is 0.1 mass% or more, a sufficient liquid phase is generated during sintering, densifying the aluminum alloy powder sintered body 10 and further improving its mechanical properties and thermal conductivity. On the other hand, if the content of rare earth metal elements is 5.0 mass% or less, the excessive generation of the liquid phase during sintering is suppressed, and an aluminum alloy powder sintered body 10 with excellent shape stability can be obtained. Furthermore, the content of rare earth metal elements is more preferably 0.1 mass% or more, and even more preferably 0.3 mass% or more. In addition, the content of rare earth metal elements is more preferably 4 mass% or less, and even more preferably 3 mass% or less.

[0036] Here, it is preferable to use one or more rare earth metal elements selected from lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), europium (Eu), samarium (Sm), terbium (Tb), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu).

[0037] In particular, it is preferable that the element be one or more selected from praseodymium (Pr), neodymium (Nd), europium (Eu), samarium (Sm), terbium (Tb), gadolinium (Gd), dysprosium (Dy), holmium (Ho), thulium (Tm), ytterbium (Yb), and lutetium (Lu).

[0038] Next, an example of a method for manufacturing the aluminum alloy powder sintered body 10 according to this embodiment will be described. A container made of tantalum with boron nitride powder coated on its inner wall is filled with raw material powder using a tap. Oxygen partial pressure 1 x 10 -6 The aluminum alloy powder sintered body 10 of this embodiment can be produced by placing it in a furnace maintained in an argon atmosphere below Pa and heating it in the range of 645°C to 650°C for a predetermined time.

[0039] According to the aluminum alloy powder sintered body 10 of this embodiment, which has the above configuration, the precipitated alloy phase 12 contains an oxide film thickness t formed on the precipitated alloy phase 12 when the precipitated alloy phase 12 is exposed to air at room temperature, which is in the range of 0.5 nm to 10 μm. Therefore, the precipitated alloy phase 12 exists stably without oxidation inside the sintered body which is not exposed to air, and the penetration of oxygen into the interior is suppressed, making it possible to obtain stable and high mechanical properties and thermal conductivity.

[0040] In this embodiment, when the thermal conductivity of the aluminum alloy powder sintered body 10 is set to 195 W / (m·K) or higher, it reliably possesses high thermal conductivity and can be applied to a wide range of applications.

[0041] Furthermore, in the aluminum alloy powder sintered body 10 of this embodiment, if the precipitated alloy phase 12 contains aluminum and eutectic elements, a liquid phase is sufficiently formed during sintering, making densification easier and ensuring high mechanical properties and thermal conductivity can be reliably obtained.

[0042] Furthermore, in the aluminum alloy powder sintered body 10 of this embodiment, if the precipitated alloy phase 12 contains rare earth metal elements, the thermal conductivity of aluminum is ensured, and high mechanical properties and thermal conductivity can be reliably obtained.

[0043] Furthermore, in the aluminum alloy powder sintered body 10 of this embodiment, if the content of rare earth metal elements in the entire sintered body is within the range of 0.1 mass% to 5.0 mass%, an appropriate amount of liquid phase is generated during sintering, ensuring densification of the aluminum alloy powder sintered body 10 and providing excellent shape stability.

[0044] Furthermore, in the aluminum alloy powder sintered body 10 of this embodiment, the rare earth metal element is selected from lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), europium (Eu), samarium (Sm), terbium (Tb), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu). If two or more elements are selected, more preferably one or more selected from praseodymium (Pr), neodymium (Nd), europium (Eu), samarium (Sm), terbium (Tb), gadolinium (Gd), dysprosium (Dy), holmium (Ho), thulium (Tm), ytterbium (Yb), and lutetium (Lu), the thermal conductivity of aluminum is ensured, and high mechanical properties and thermal conductivity can be reliably obtained.

[0045] Although embodiments of the present invention have been described above, the present invention is not limited thereto and can be modified as appropriate without departing from the technical spirit of the invention. [Examples]

[0046] The raw material powders with the compositions shown in Table 1 are placed into a tantalum container with a boron nitride powder coating on the inner wall, and then filled by tapping. Oxygen partial pressure 1 x 10 -6 Aluminum alloy powder sintered bodies were produced by placing the samples in a furnace maintained in an argon atmosphere below Pa and sintering them under the conditions shown in Table 1. The microstructures of the obtained samples are shown in Figure 2 for Test No. 1, Figure 3 for Test No. 2, Figure 4 for Test No. 3, Figure 5 for Test No. 4, and Figure 6 for Test No. 5.

[0047] (composition) Samples were taken from the raw material powder, dissolved in acid, and measured by ICP measurement.

[0048] (Sintering density) Samples were cut from the obtained sintered body, and their density was calculated using the Archimedes method. The relative densities, with the density of pure aluminum bulk material set to 100, are shown in Table 1.

[0049] (0.2% yield strength, tensile strength, elongation) Tensile tests were performed on test specimens processed from the fabricated aluminum alloy sintered body, with a total length of 9.8 mm, a width of 2.2 mm, a thickness of 0.8 mm, a parallel length of 6.0 mm, and a width of 1.0 mm. The 0.2% yield strength, tensile strength, and elongation were measured. The measurement results are shown in Table 1.

[0050] (Thickness of oxide film after exposure to air) The resulting sintered body was subjected to cross-sectional milling using a Hitachi High-Tech Fielding IM4000II ion mill with an acceleration voltage of 6.0 kV and a discharge voltage of 1.5 kV. After 2 hours of milling, the chamber was opened to the atmosphere, and the milled surface was exposed to ambient air at room temperature and pressure. Carbon coating was applied by deposition using a Thermo Fisher Scientific Scios FIB instrument at an acceleration voltage of 30kV, and the precipitated alloy phase was cut out. The thickness of the oxide film formed on the milled surface of the precipitated alloy phase was observed using a Thermo Fisher Scientific Titan G2 80-200 scanning transmission electron microscope. The oxide film thickness was analyzed by EDS line analysis at 0.132nm intervals along a straight line from the void to the interior of the precipitated alloy phase. The EDS peak intensity of oxygen was extracted, and the peak portion, excluding the background, was fitted with a single-component Gaussian filter. The full width at half maximum was considered to be the thickness of the oxide film.

[0051] The HAADF-STEM field of view after EDS analysis and the corresponding oxygen EDS peak intensity profiles are shown in the figures. Figure 7 shows the HAADF-STEM image and EDS peak intensity for Experiment No. 1, Figure 8 shows the HAADF-STEM image and EDS peak intensity for Experiment No. 2, Figure 9 shows the HAADF-STEM image and EDS peak intensity for Experiment No. 3, Figure 10 shows the HAADF-STEM image and EDS peak intensity for Experiment No. 4, and Figure 11 shows the HAADF-STEM image and EDS peak intensity for Experiment No. 5. In addition, EDS spectra were obtained from the entirety of three arbitrary fields (magnification 500x) using a scanning electron microscope with an acceleration voltage of 10kV on the milling surface of the sintered body. The weight ratio of Al to Dy or Sm was calculated from the peak intensities of the Al-K edge, Dy-L edge, or Sm-L edge included in the spectra. The results are shown in Table 1.

[0052] (Thermal conductivity) The sintered body was polished to approximately 10 mm square and 2 mm thick, and the thermal diffusivity and specific heat capacity were calculated at 25.0°C using the laser flash method (average of 3 points). The sintered body density, calculated using the Archimedes method, was then converted to thermal conductivity.

[0053] [Table 1]

[0054] In Test No. 1, a mixed powder of Al powder and Dy2O3 powder (Dy content 1.6 mass%) was used as the raw material powder and sintered under conditions of holding at 650°C for 48 hours. In the resulting aluminum alloy powder sintered body, the oxide film thickness of the precipitated alloy phase after exposure to air was 3.7 nm, and the sinter density was 93.3%. Furthermore, as shown in Figure 12, the 0.2% yield strength was 34 MPa, the tensile strength was 59 MPa, and the elongation was 24%, indicating excellent mechanical properties. In addition, the thermal conductivity was 222 W / (m·K), indicating sufficient thermal conductivity.

[0055] In Test No. 2, Al-0.33mass%Dy alloy powder was used as the raw material and sintered under conditions of holding at 650°C for 48 hours. The resulting aluminum alloy powder sintered body had an oxide film thickness of 2.9 nm of the precipitated alloy phase after exposure to air, and a sintering density of 94.5%. Furthermore, as shown in Figure 13, it exhibited excellent mechanical properties, with a 0.2% yield strength of 28 MPa, a tensile strength of 50 MPa, and an elongation of 25%. In addition, it had sufficient thermal conductivity with a thermal conductivity of 213 W / (m·K).

[0056] In Test No. 3, Al-0.30mass%Sm alloy powder was used as the raw material and sintered under conditions of holding at 650°C for 1 hour. The resulting aluminum alloy powder sintered body had an oxide film thickness of 2.7 nm of the precipitated alloy phase after exposure to air, and a sintering density of 92.2%. Furthermore, as shown in Figure 14, it had a 0.2% yield strength of 27 MPa, a tensile strength of 47 MPa, and an elongation of 26%, demonstrating excellent mechanical properties. In addition, it had a thermal conductivity of 195 W / (m·K), indicating sufficient thermal conductivity.

[0057] In Test No. 4, Al-0.73mass%Sm alloy powder was used as the raw material and sintered under conditions of holding at 650°C for 48 hours. The resulting aluminum alloy powder sintered body had an oxide film thickness of 6.2 nm of the precipitated alloy phase after exposure to air, and a sintering density of 99.9%. Furthermore, as shown in Figure 15, it had excellent mechanical properties, with a 0.2% yield strength of 27 MPa, a tensile strength of 51 MPa, and an elongation of 26%. In addition, it had sufficient thermal conductivity with a thermal conductivity of 224 W / (m·K).

[0058] In Test No. 5, Al-1.7mass%Sm alloy powder was used as the raw material and sintered under conditions of holding at 650°C for 1 hour. The resulting aluminum alloy powder sintered body had an oxide film thickness of 3.3 nm of the precipitated alloy phase after exposure to air, and a sintering density of 99.9%. Furthermore, as shown in Figure 16, it had a 0.2% yield strength of 30 MPa, a tensile strength of 60 MPa, and an elongation of 27%, demonstrating excellent mechanical properties. In addition, it had a thermal conductivity of 216 W / (m·K), indicating sufficient thermal conductivity.

[0059] Based on the results of the above verification experiments, it has been confirmed that the present invention makes it possible to provide an aluminum alloy powder sintered body that can stably obtain high mechanical properties and thermal conductivity.

Claims

1. The precipitated alloy phase includes an aluminum precipitated alloy phase, wherein the thickness of the oxide film formed on the precipitated alloy phase when the precipitated alloy phase is exposed to air is in the range of 0.5 nm to 6.2 nm. An aluminum alloy powder sintered body characterized in that the precipitated alloy phase contains rare earth metal elements, and the total content of the rare earth metal elements in the sintered body is in the range of 0.1 mass% to 5.0 mass%.

2. The aluminum alloy powder sintered body according to claim 1, characterized in that its thermal conductivity is 195 W / (m·K) or higher.

3. The aluminum alloy powder sintered body according to claim 1, characterized in that the precipitated alloy phase contains aluminum and a eutectic element.

4. The aluminum alloy powder sintered body according to claim 1, characterized in that the rare earth metal element is one or more selected from lanthanum, cerium, praseodymium, neodymium, europium, samarium, terbium, gadolinium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium.

5. The aluminum alloy powder sintered body according to claim 1, characterized in that the rare earth metal element is one or more selected from praseodymium, neodymium, europium, samarium, terbium, gadolinium, dysprosium, holmium, thulium, ytterbium, and lutetium.

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