Aluminum powder product

Abstract

In the aluminum powder product (1), the BET specific surface area of the powder product (1) is 0.16 m < 2 > / g or more, the phosphorus concentration of the entire powder product (1) as measured by a molybdenum blue method is 1 * 10 <-3 > mass% or more, and the ratio of the P2s peak intensity IP2s at 191.5 eV to the Cl2p peak intensity ICl2p at 199.0 eV, IP2s / ICl2p, in the photoelectron spectroscopy of the powder product (1) as measured by an X-ray photoelectron spectroscopy (XPS) method is 1.00 or more.

Description

Technical Field

[0001] The present invention relates to an aluminum powder product.

[0002] This application claims priority based on Patent Application No. 2023-055049 filed in Japan on March 30, 2023, and incorporates its content herein. Background Art

[0003] Aluminum is used in radiators of devices etc. due to its light weight and good electrical / thermal conductivity, but it is a representative metal with difficult sinterability, and in powder sintering, densification of the structure has always been a problem. In particular, in the case of heat sink materials etc. as heat exchange materials where complex and precise shape control is required, from the perspective of properties, powder sintering methods such as metal injection molding or laminated molding are usually adopted to achieve it.

[0004] In powder sintering methods, a hopper or a bin is usually used as a feeder for powder, but if the powder has low fluidity, bridging or rat-holing occurs in the feeder, and thus the flow path is blocked. As a result, the flow of the powder stagnates, and a part of the powder undergoes solidification / compositional change etc. under the pressure of other powder, becoming a cause of poor sintering. Generally, the more spherical the particles are in shape, the higher the fluidity of the powder, but there are many cases where the shape of the particles is difficult to control in the manufacturing process.

[0005] In the past, when the desired physical properties could not be obtained in the manufacturing stage, surface treatment was performed on the powder. For example, there is known a technique of coating the surface of particles such as titanium alloy and nickel alloy particles by adding nanoparticles such as silica or alumina surface-modified with an organic substance. And there is known a technique of depositing a nanostructure on the surface of particles by using thermal plasma treatment to reduce the contact area between particles and improve fluidity (refer to Patent Document 1).

[0006] And there is known a technique of performing heat treatment on powder whose shear adhesion has increased and fluidity has decreased due to particle decomposition treatment to form an oxide film on the surface of the particles, thereby reducing the shear adhesion and restoring the fluidity (refer to Patent Document 2).

[0007] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2019-112699

[0008] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2019-183199

[0009] However, heat treatment or thermal plasma treatment of powders requires dedicated equipment and cannot be simply carried out. Also, in the case of aluminum, due to its low melting point, it is difficult to stay only on the surface treatment of particles during thermal plasma treatment, and the particle shape changes, which has a great impact on powder properties such as packing density. Therefore, it is considered difficult to apply.

[0010] Therefore, it is desirable to provide a surface treatment technology that imparts high fluidity to powder particles while maintaining the outer diameter / shape of aluminum powder particles. Summary of the Invention

[0011] The present invention has been completed in view of the above problems, and an object thereof is to provide an aluminum powder product having high fluidity while maintaining the outer diameter / shape of the particles.

[0012] As a result of various studies, the present invention provides the following aluminum powder products.

[0013] (1) The aluminum powder product according to aspect (1) of the present invention is characterized in that the BET specific surface area of the powder product is 0.16 m 2 / g or more, and the phosphorus concentration of the entire powder product measured by the molybdenum blue method is 1×10 -3 mass% or more, and in the photoelectron spectrum of the powder product measured by X-ray photoelectron spectroscopy (XPS method), the intensity I of the P2s peak at 191.5 eV P2s and the intensity I of the Cl2p peak at 199.0 eV Cl2p ratio I P2s / I Cl2p is 1.00 or more.

[0014] The aluminum powder product has a specified BET specific surface area, a specified overall phosphorus concentration, and in the photoelectron spectrum of the particles of the powder product, the intensity of the P2s peak at 191.5 eV is equal to or greater than the intensity of the Cl2p peak at 199.0 eV. That is, the phosphoric acid-based compound exists in an amount equal to or greater than the inevitable impurities of the chlorine-containing compound. Thus, the fluidity of the aluminum powder product is improved. Therefore, clogging of the aluminum powder product in the flow path of the silo or hopper containing the aluminum powder product can be prevented.

[0015] Since the particle structure of the aforementioned aluminum powder product can be simply achieved without affecting the particle size, it is easy to obtain an aluminum powder product with a target particle size and control the packing density and the like to target values.

[0016] Moreover, the aforementioned aluminum powder product can suppress the generation of hydrogen in hot water, and thus has excellent corrosion resistance.

[0017] (2) Regarding aspect (2) of the present invention, in the aluminum powder product of aspect (1), it is preferred that there is a high phosphorus concentration region in a region with a depth of less than 30 nm from the outermost surface of particles constituting the powder product, the phosphorus concentration in the high phosphorus concentration region is at least 3.5 times higher than the phosphorus concentration in a region with a depth of more than 30 nm from the outermost surface of the particles, and phosphate-based compounds are concentrated in the high phosphorus concentration region.

[0018] Specifically, the region at a depth exceeding 30 nm from the outermost surface of the particle is a region at a depth exceeding 30 nm and not more than 60 nm from the outermost surface.

[0019] According to the analysis by the XPS method, the phosphoric acid compound is estimated to be an oxygen-containing acid of phosphorus.

[0020] If the high-concentration region of phosphorus exists in a region from the outermost surface to a depth of 30 nm, and the phosphoric acid-based compound is concentrated in this region, an aluminum powder product that exhibits the above-mentioned excellent effects can be obtained.

[0021] (3) Regarding aspect (3) of the present invention, in the aluminum powder product of aspect (1) or (2), it is preferred that the volume-based 50% cumulative particle size (median particle size D 50 ) is 15 μm or more and 45 μm or less, and the Hausner ratio of the powder product is 1.14 or less.

[0022] If the median particle size D 50 Aluminum powder products with a median particle size of 15 μm or more are highly safe in terms of the handling of the powder products. 50 When the particle size is 15 μm or more and 45 μm or less, the aluminum powder has excellent handling properties in laminated molding applications, and thus an aluminum powder product suitable for laminated molding can be provided.

[0023] When the Hausner ratio of the powder product is 1.14 or less, the powder product has excellent fluidity. Moreover, the excellent fluidity helps to ensure the fluidity required for powder sintering, so that an aluminum powder product suitable for powder sintering can be provided.

[0024] (4) Regarding aspect (4) of the present invention, in the aluminum powder product described in any one of aspects (1) to (3), the sphericity measured by an image analysis method is preferably 0.93 or more.

[0025] When the sphericity of the particles is 0.93 or more, the particles have a shape close to a sphere, and thus it is preferred in terms of imparting good fluidity.

[0026] (5) Regarding aspect (5) of the present invention, in the aluminum powder product described in any one of aspects (1) to (4), the aluminum powder product is preferably used for laminated molding.

[0027] According to an aspect of the present invention, there is provided an aluminum powder product having a specified BET specific surface area, a specified overall phosphorus concentration, and in the photoelectron spectrum of the powder product, the intensity of the P2s peak at 191.5 eV is equal to or greater than the intensity of the Cl2p peak at 199.0 eV. Thereby, the fluidity of the aluminum powder product is improved.

[0028] Therefore, clogging of the aluminum powder product can be prevented in the flow path of the silo or hopper that houses the aluminum powder product.

[0029] Since the particle structure of the aforementioned aluminum powder product can be achieved without affecting the particle size, it is easy to obtain an aluminum powder product with a target particle size and to control the packing density and the like to target values.

[0030] In addition, the aforementioned aluminum powder product can suppress the generation of hydrogen in hot water, and thus has excellent corrosion resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a partial cross-sectional view of the particle main body of the aluminum powder product according to the first embodiment.

[0032] Figure 2A is the concentration distribution in the depth direction of each element of the aluminum powder product of Example 1.

[0033] Figure 2B is the concentration distribution in the depth direction of each element of the aluminum powder product of Example 2.

[0034] Figure 2C is the concentration distribution in the depth direction of each element of the aluminum powder product of Example 3.

[0035] Figure 2D is the concentration distribution in the depth direction of each element of the aluminum powder product of Example 4.

[0036] Figure 2E is the concentration distribution in the depth direction of each element of the aluminum powder product of Comparative Example 1.

[0037] Figure 2F is the concentration distribution in the depth direction of each element of the aluminum powder product of Comparative Example 2.

[0038] Figure 2G is the concentration distribution in the depth direction of each element of the aluminum powder product of Comparative Example 3.

[0039] Figure 2H is the concentration distribution in the depth direction of each element of the aluminum powder product of Comparative Example 4.

[0040] Figure 3 is the surface secondary electron SEM image of the aluminum powder product of Comparative Example 1.

[0041] Figure 4 It is a secondary electron SEM image of the surface of the aluminum powder product of Example 1.

[0042] Figure 5A It is the X-ray photoelectron spectroscopy of the aluminum powder products of Example 1 and Comparative Example 1, and is a graph showing the binding energy in the range of 190 to 210 eV.

[0043] Figure 5B It is the X-ray photoelectron spectroscopy of the aluminum powder products of Example 1 and Comparative Example 1, and is a graph showing the binding energy in the range of 123 to 143 eV.

[0044] Figure 6A It is the X-ray photoelectron spectroscopy of the aluminum powder products of Example 2 and Comparative Example 2, and is a graph showing the binding energy in the range of 190 to 210 eV.

[0045] Figure 6B It is the X-ray photoelectron spectroscopy of the aluminum powder products of Example 2 and Comparative Example 2, and is a graph showing the binding energy in the range of 123 to 143 eV.

[0046] Figure 7A It is the X-ray photoelectron spectroscopy of the aluminum powder products of Example 3 and Comparative Example 3, and is a graph showing the binding energy in the range of 190 to 210 eV.

[0047] Figure 7B It is the X-ray photoelectron spectroscopy of the aluminum powder products of Example 3 and Comparative Example 3, and is a graph showing the binding energy in the range of 123 to 143 eV.

[0048] Figure 8A It is the X-ray photoelectron spectroscopy of the aluminum powder products of Example 4 and Comparative Example 4, and is a graph showing the binding energy in the range of 190 to 210 eV.

[0049] Figure 8B It is the X-ray photoelectron spectroscopy of the aluminum powder products of Example 4 and Comparative Example 4, and is a graph showing the binding energy in the range of 123 to 143 eV. Detailed implementation mode

[0050] Hereinafter, the present invention will be described in detail, but the present invention is not limited to the embodiments described below.

[0051] The aluminum powder product 1 of the present embodiment is composed of a plurality of spherical particle bodies (particles constituting the powder product) 2. Figure 1A partial cross-sectional view showing the particle main body 2 is presented. In the outermost surface region of the particle main body 2, there is a high-concentration region 2a of phosphorus (P). The high-concentration region 2a of phosphorus is more preferably formed over the entire surface (100% by area) of the particle main body 2, but the high-concentration region 2a of phosphorus may also be formed over almost the entire surface (90% by area or more) of the particle main body 2 or over most of the surface (60% by area or more) of the particle main body 2. Additionally, it is difficult to accurately measure the area ratio of the high-concentration region 2a of phosphorus with respect to the surface area of the particle main body 2. As described above, approximate area ratios are exemplified, but the present invention is not limited to the above area ratios.

[0052] As described later, the high-concentration region 2a of phosphorus is formed by immersing raw material powder in a liquid medicine, so there may be a region on a part of the surface of the particle main body 2 where the high-concentration region 2a of phosphorus is not formed due to non-reaction.

[0053] The aluminum powder product 1 contains aluminum or an aluminum alloy and 1×10 -3 mass% or more of phosphorus. In addition, aluminum has a purity of 99% or more and is composed only of Al and unavoidable impurities. In the present embodiment, aluminum is also referred to as pure aluminum.

[0054] Hereinafter, the composition of the aluminum or aluminum alloy, which is a component other than phosphorus in the aluminum powder product 1, will be described. Assuming the total composition of the aluminum or aluminum alloy is 100 mass%, the amounts of the respective elements will be described. In the aluminum powder product 1, the amount of phosphorus is extremely small compared to the amounts of the other elements whose contents are determined. Therefore, the amounts of the respective elements calculated by assuming the total composition of the aluminum powder product 1 to be 100 mass% are substantially the same as the amounts of the respective elements calculated by assuming the total composition of the aluminum or aluminum alloy to be 100 mass%.

[0055] The elements contained in the aluminum alloy are not particularly limited, and any elements commonly known to be contained in aluminum alloys may be contained. For example, the aluminum alloy has the following composition: Si: 13.5% or less, Mg: 5.6% or less, Ti: 0.2% or less, Cr: 0.35% or less, Mn: 1.5% or less, Fe: 0.7% or less, Cu: 6.0% or less, and Zn: 6.1% or less, with the balance being Al and unavoidable impurities. In this composition, since the ranges of the amounts of the respective elements include 0%, the composition of aluminum is also included. Therefore, it can also be said that the aluminum powder product 1 has the following composition: Si: 13.5% or less, Mg: 5.6% or less, Ti: 0.2% or less, Cr: 0.35% or less, Mn: 1.5% or less, Fe: 0.7% or less, Cu: 6.0% or less, Zn: 6.1% or less, and P: 1×10 -3 % or more, with the balance being Al and unavoidable impurities.

[0056] As an example, conventional aluminum or aluminum alloys represented by the A1000 series, A2000 series, A3000 series, A4000 series, A5000 series, A6000 series, A7000 series, etc. specified by the JIS standard can also be used. Alternatively, other conventional aluminum alloys to which elements not included in these series of aluminum alloys are added can also be used.

[0057] A1050, as an example of the A1000 series, represents aluminum with a purity of 99.5% or more, and Fe and Si, etc. may also be included as inevitable impurities.

[0058] The A1100 series represents aluminum with a purity of 99% or more. As an example, A1100 aluminum has the following composition: the total of Fe and Si is 1.0% or less, Cu: about 0.05 - 0.20%, Mn: 0.05% or less, and Zn: 0.1% or less, and the balance is Al and inevitable impurities. Elements other than Al can also be regarded as inevitable impurities. In addition, unless otherwise specified, the % representing the content of an element means mass %.

[0059] The A2000 series represents aluminum alloys to which a large amount of Cu is added. As an example, A2024 aluminum alloy has the following composition: Si: 0.5% or less, Fe: 0.5% or less, Cu: 3.8 - 4.9%, Mn: 0.3 - 0.9%, Mg: 1.2 - 1.8%, Cr: 0.1% or less, and Zn: 0.25% or less, and the balance is Al and inevitable impurities.

[0060] The A3000 series represents Al-Mn series aluminum alloys. As an example, A3003 aluminum alloy has the following composition: Si: 0.6% or less, Fe: 0.7% or less, Cu: 0.05% or less, Mn: 1.0 - 1.5%, and Zn: 0.1% or less, and the balance is Al and inevitable impurities.

[0061] The A4000 series represents aluminum alloys to which Si is added. As an example, A4032 aluminum alloy has the following composition: Si: 11.0 - 13.5%, Fe: 1.0% or less, Cu: 0.5 - 1.3%, Mg: 0.8 - 1.3%, Cr: 0.10% or less, and Zn: 0.25% or less, and the balance is Al and inevitable impurities.

[0062] The A5000 series represents aluminum alloys to which Mg is added. As an example, A5052 aluminum alloy has the following composition: Si: 0.25% or less, Fe: 0.4% or less, Cu: 0.10% or less, Mn: 0.1% or less, Mg: 2.2 - 2.8%, Cr: 0.15 - 0.35%, and Zn: 0.1% or less, and the balance is Al and inevitable impurities.

[0063] The A6000 series represents an aluminum alloy added with Mg and Si. As an example, the A6061 aluminum alloy contains the following composition: Si: 0.4 - 0.8%, Fe: 0.7% or less, Cu: 0.15 - 0.4%, Mn: 0.15% or less, Mg: 0.8 - 1.2%, Cr: 0.15 - 0.35%, Zn: 0.25% or less, and Ti: 0.15% or less, with the balance being Al and unavoidable impurities.

[0064] The A7000 series represents an aluminum alloy mainly added with Zn and Mg. As an example, the A7075 aluminum alloy contains the following composition: Si: 0.4% or less, Fe: 0.5% or less, Cu: 1.2 - 2.0%, Mn: 0.3% or less, Mg: 2.1 - 2.9%, Cr: 0.18 - 0.35%, Zn: 5.1 - 6.1%, and Ti: 0.2% or less, with the balance being Al and unavoidable impurities.

[0065] "The concentration of phosphorus (P) contained in the whole aluminum powder product: 1 × 10 -3 mass% or more (10 mass ppm or more)"

[0066] If the phosphorus concentration contained in the whole aluminum powder product 1 is less than 10 mass ppm (less than 1 × 10 -3 mass%), there is a tendency that an effective high - concentration region 2a cannot be formed. Since the phosphorus concentration of the whole aluminum powder product 1 according to this embodiment is 10 mass ppm or more, a high - concentration region 2a of phosphorus that can impart good corrosion resistance and fluidity to the aluminum powder product 1 is formed on the outermost surface of the particle main body 2. The phosphorus concentration of the whole aluminum powder product 1 is preferably 10 mass ppm or more and 100 mass ppm or less, more preferably 20 mass ppm or more and 80 mass ppm or less.

[0067] "I P2s / I Cl2p : 1.00 or more"

[0068] In the photoelectron spectrum of the aluminum powder product 1 measured by X - ray photoelectron spectroscopy (XPS method), when the intensity I P2s of the P2s peak is less than the intensity I Cl2p of the Cl2p peak, the amount of the phosphoric acid - based compound present is less than the amount of the chlorine - containing compound present as an unavoidable impurity, and there is a tendency that an effective high - concentration region 2a of phosphorus cannot be formed.

[0069] In the aluminum powder product 1 of this embodiment, the intensity I P2s of the P2s peak is the intensity I Cl2pAs described above. Therefore, a high-concentration region 2a of phosphorus is formed on the outermost surface of the particle main body 2. Due to this high-concentration region 2a of phosphorus, the conductivity decreases, so that the particle main body 2 becomes charged. Through electrostatic repulsion, the friction between the particle main bodies 2 is reduced, thereby improving the fluidity. In order to obtain such an effect, the P2s peak intensity I P2s and the Cl2p peak intensity I Cl2p The ratio I P2s / I Cl2p is preferably 1.00 or more and 100 or less, more preferably 1.00 or more and 10.0 or less.

[0070] "BET specific surface area: 0.16 m 2 / g or more"

[0071] By setting the BET specific surface area to 0.16 m 2 / g or more, the Hausner ratio, which is an index of fluidity, can be improved. The BET specific surface area is preferably 0.16 m 2 / g or more and 0.9 m 2 / g or less, more preferably 0.16 m 2 / g or more and 0.4 m 2 / g or less.

[0072] "There is a high-concentration region of phosphorus in the phosphoric acid-based compound"

[0073] Based on the analysis results (concentration distribution in the depth direction of each element) of the samples in the examples described later by the EDS method (energy dispersive spectroscopy), it is inferred that the high-concentration region 2a of phosphorus exists in a region where the depth from the outermost surface of the particle main body 2 is 30 nm or less. The phosphorus concentration in the high-concentration region 2a of phosphorus is 3.5 times or more higher than the phosphorus concentration in the region where the depth from the outermost surface of the particle main body 2 exceeds 30 nm. And, based on the P2p spectrum (peak of P2p) and P2s spectrum (peak of P2s) obtained from the analysis results (photoelectron spectrum) of the XPS method (X-ray photoelectron spectroscopy) of the sample described later, it can be inferred that phosphorus exists in the state of a phosphoric acid-based compound in the high-concentration region 2a of phosphorus. According to the analysis by the XPS method, it is inferred that the phosphoric acid-based compound is an oxyacid of phosphorus. Examples of the phosphoric acid-based compound include hypophosphorous acid, phosphonic acid, phosphorous acid, phosphoric acid, diphosphoric acid, triphosphoric acid and metaphosphoric acid, and also phosphoric acid derivatives such as hydroxyethylidene diphosphonic acid, etc., but in the analysis by the XPS method, it is difficult to determine the specific compound.

[0074] Further, in the concentration distribution in the depth direction of each element, when observing the elemental distribution of Al, as going from the outermost surface toward the depth direction, the EDS spectral intensity (detection signal intensity) of Al gradually increases, and the depth region where the distance from the outermost surface exceeds 30 nm becomes the region where the EDS spectral intensity of Al is stable. Thus, it can be inferred that a certain coating film is formed in the region from the outermost surface to about 30 nm in depth in the powder main body 2, and it can be inferred that a high-concentration region 2a of phosphorus is formed within this coating film.

[0075] "50% cumulative particle size (median particle size D 50 ) based on volume: 15 μm or more and 45 μm or less"

[0076] In the aluminum powder product 1, the 50% cumulative particle size based on volume is preferably 15 μm or more and 45 μm or less. The 50% cumulative particle size based on volume is more preferably 20 μm or more and 35 μm or less.

[0077] Regarding the aluminum powder product 1, if the median particle size D 50 is 15 μm or more and 45 μm or less, when using the aluminum powder product 1 in powder metallurgy, appropriate fluidity can be ensured and good molding accuracy can be obtained. Therefore, an aluminum powder product 1 with good fluidity and excellent sinterability can be obtained.

[0078] When the median particle size (D 50 ) is less than 15 μm, the fluidity will decrease, and the possibility of ignition and the risk caused by scattering become high. When the median particle size (D 50 ) exceeds 45 μm, the fluidity will increase, but it is difficult to obtain a high-density sintered body when using the aluminum powder product 1 in the manufacturing equipment of powder metallurgy.

[0079] "Sphericity: 0.93 or more"

[0080] The sphericity of the particle main body 2 of the aluminum powder product 1 is measured by an image analysis method using an image analysis device such as the dry-type image analyzer Morphologi4 manufactured by Malvern. If the sphericity is less than 0.93, the particle shape deviates from a spherical shape, and it is likely to cause a decrease in the packing density or fluidity during layer-by-layer molding. Thus, the sphericity is preferably 0.93 or more. The sphericity is more preferably 0.93 or more and 1.00 or less, and further preferably 0.97 or more and 1.00 or less.

[0081] "Hausner ratio: 1.14 or less"

[0082] When the Hausner ratio exceeds 1.14, the fluidity decreases, and blockages are likely to occur in flow paths such as hoppers. The Hausner ratio is preferably 1.14 or less. In this case, the fluidity required for powder sintering can be ensured. The Hausner ratio is more preferably 1.00 or more and 1.14 or less, and further preferably 1.00 or more and 1.10 or less.

[0083] "Method for manufacturing aluminum powder product"

[0084] The manufacturing method of the aluminum powder product 1 has a process of producing raw material powder, a process of removing the oxide film using a rust remover, and a process of forming a coating film using an anti-rust agent. A rust remover containing a phosphoric acid-based inorganic or organic molecule and an anti-rust agent containing a phosphoric acid-based inorganic or organic molecule are used. Thereby, the phosphorus concentration of the entire aluminum powder product 1 is set to 1×10 -3 mass% or more. And a high-concentration region 2a of phosphorus is formed. The phosphoric acid-based inorganic or organic molecule is one or more selected from phosphoric acid, derivatives of phosphoric acid, salts of phosphoric acid, and salts of derivatives of phosphoric acid. Specifically, phosphoric acid, hydroxyethylidene diphosphonic acid, sodium phosphate, etc. can be mentioned.

[0085] When manufacturing the aluminum powder product 1, first, raw material powder is produced.

[0086] As an example, when producing raw material powder, a powder manufacturing method such as the atomization method can be applied. In the atomization method, a metal melt of the target composition is prepared, and the metal melt is sprayed at high speed through a nozzle in an atmosphere such as air, nitrogen, or a vacuum atmosphere, and the raw material powder is manufactured by rapidly cooling the droplets of the metal melt.

[0087] In the case of manufacturing the aluminum powder product 1 containing pure aluminum, a melt of pure aluminum is used. In the case of manufacturing the aluminum powder product 1 containing an aluminum alloy, a melt of the aluminum alloy of the target composition is used.

[0088] As a method for manufacturing the melt of the aluminum alloy of the target composition, as an example, a method of using an aluminum alloy of the target composition ratio as the base material, or a method of forming an alloy melt by combining high-purity aluminum with a purity of 99.5% or more and a base material of various additive elements that become the melt of the target composition ratio can be mentioned.

[0089] When the metal melt is sprayed into the atmosphere to produce raw material powder, the particles of the raw material powder usually obtained have a spherical shape or a shape similar thereto.

[0090] The volume-based 50% cumulative average particle diameter (D 50 : μm) of the raw material powder produced here is, for example, 15 μm or more and 45 μm or less.

[0091] In the case of manufacturing raw material powder, an aluminum oxide film is formed on the outer peripheral surface of the particles of the raw material powder. When the atomization method is carried out in a nitrogen atmosphere or a vacuum atmosphere to manufacture the raw material powder, even if the surface of the particles is not oxidized immediately after manufacturing, when it is taken out from the atomization device or the manufacturing atmosphere and provided to the next process in the atmosphere, an oxide film will inevitably be formed on the surface of the particles of the raw material powder over time.

[0092] The aluminum oxide film becomes a cause of hindrance to sintering in the sintering described later, and therefore it is preferably removed as much as possible. Therefore, in the present embodiment, a process of removing the oxide film by immersing the produced raw material powder in a solution of a rust remover is carried out.

[0093] When the raw material powder is immersed in a solution of a rust remover, the solution of the rust remover can be appropriately diluted by adding a solvent such as water and used. And when immersed in a solution of a rust remover, stirring or the like can be carried out to promote the rust removal effect. When stirring is carried out, an ultrasonic cleaner or a stirrer having a rotating blade can be used.

[0094] The raw material powder can be immersed in a solution of a rust remover, and then the surface of the raw material powder can be cleaned with a cleaning solution such as pure water or tap water. After removing the rust on the surface of the particles of the raw material powder with a rust remover, when the possibility of re-oxidation due to cleaning with pure water or tap water is low, it is preferable to remove the rust remover by cleaning with pure water or tap water. It is considered that if the rust removal effect of the rust remover on the oxide film is sufficient, it will not be easily re-oxidized even after cleaning after rust removal.

[0095] When removing the oxide film, it is preferable to remove the oxide film from the entire surface of the particles of the raw material powder, but when the oxide film is sufficiently thin or when the remaining area of the oxide film is small, the oxide film can remain on a part of the surface.

[0096] As a rust remover containing phosphoric acid-based inorganic or organic molecules, a solution containing an organic acid such as citric acid, an acidic solvent such as phosphoric acid, or a basic solvent such as sodium hydroxide can be used. For example, a rust remover containing phosphoric acid-based inorganic or organic molecules and amine-based carboxylates can be used.

[0097] Or, as an example, a composition containing 2.5 to 10% by mass of citric acid, 2.5 to 10% by mass of propylene glycol monobutyl ether, and 2.5 to 10% by mass of phosphoric acid as main components and further containing 2.5% by mass or less of phosphonic acid and 2.5% by mass or less of mineral spirits (aliphatic hydrocarbons) can be adopted.

[0098] As an example of a rust remover containing phosphoric acid-based inorganic or organic molecules and amine-based carboxylates, specifically, a rust remover manufactured by Tanimura Corporation: BF4-26 etc. can be used.

[0099] For example, 100 to 500 ml of an aqueous solution of a rust remover containing the above phosphoric acid-based inorganic or organic molecules and amine-based carboxylate and about 150 to 700 g of raw material powder are put into a container, the solution is stirred and mixed for 1 to 60 minutes, and the supernatant is removed in a state where the raw material powder has settled. The raw material powder precipitated in the aqueous solution of the rust remover can be rinsed with a necessary and sufficient amount of pure water or the like and sent to the next process. In the rinsing, pure water is put into the container to stir the solution, and then the solution is allowed to stand and the supernatant is removed. Further, as a process to replace rinsing, a weakly alkaline and water-soluble agent can be used to neutralize the remaining rust remover.

[0100] If the oxide film of the raw material powder is removed, then the raw material powder is immersed in a solution of a rust preventive agent, and a film of the rust preventive agent is formed on the surface of the raw material powder.

[0101] In this case, in a state where the raw material powder is accommodated in the above container, pure water can be added and rinsing can be repeated the required number of times, and then the following rust preventive agent is put into the container to perform an immersion treatment based on the rust preventive agent.

[0102] When the raw material powder is immersed in a solution of a rust preventive agent, the solution of the rust preventive agent can be appropriately diluted by adding a solvent such as water and used. Further, when immersed in an aqueous solution of a rust preventive agent, stirring or the like can be performed to promote the formation of the film. It can be immersed in a solution of a rust preventive agent, and then the surface of the raw material powder is washed with a cleaning liquid such as tap water.

[0103] When rust removal of the raw material powder is performed and then it is immersed in a solution of a rust preventive agent, the following processes can be performed in the same container, but rust removal and rust prevention can also be performed separately in different containers.

[0104] (1) Immerse aluminum powder in a solution containing a rust remover and stir the solution.

[0105] (2) Then remove the supernatant and add pure water to the container to rinse the raw material powder.

[0106] (3) Then remove the supernatant and further add a rust preventive agent to the same container and stir the solution.

[0107] As a rust preventive agent containing phosphoric acid-based inorganic or organic molecules, an aqueous solution of a vapor-phase rust preventive agent containing one or a mixture of amine-based nitrites, amine-based carboxylates, amine-based chromates, carboxylic acid esters, heterocyclic compounds and phosphoric acid-based inorganic or organic molecules can be used. Further, an organic solvent containing these salts, esters, and compounds can also be used.

[0108] As an example of a rust preventive agent containing a phosphoric acid-based inorganic or organic molecule and an amine-based carboxylate, an aqueous solution containing 2.5 to 10% by mass of potassium hydrogen phthalate as a main component and further containing 2.5% by mass or less of cyclo-carboxylic acid, 2.5% by mass or less of disodium metasilicate, and 2.5% by mass or less of trisodium phosphate can be used.

[0109] In addition, solutions such as surfactants containing phosphoric acid-based inorganic or organic molecules and carboxylates can be applied.

[0110] As an example of a rust preventive agent containing a phosphoric acid-based inorganic or organic molecule and an amine-based carboxylate, specifically, a rust preventive agent manufactured by Tanimura Corporation: BF4-16 can be used.

[0111] In addition, as a rust preventive agent, Mechahibiter #325 manufactured by Nippon Mecha Chemical Co., Ltd. can be used, and inhibitors, chelating agents, water-soluble rust preventive agents, and vapor-phase rust preventive agents containing amine-based carboxylic acids can also be used as components for rust prevention effects.

[0112] If it is immersed in a solution of a rust preventive agent and then the raw material powder is taken out of the solution, Figure 1 the aluminum powder product 1 as shown can be obtained.

[0113] It can be immersed in a solution of a rust preventive agent, and then the surface of the particles of the raw material powder can be cleaned with a cleaning liquid such as pure water or tap water. When a coating film is formed on the surface of the particles of the raw material powder by the rust preventive agent, it can be cleaned with pure water or tap water, etc. It is considered that if the coating film can be sufficiently formed by the rust preventive agent, the coating film will not be easily peeled off even after the rust prevention treatment and cleaning.

[0114] The aluminum powder product 1 having a coating film is recovered from the solution and dried in an atmosphere such as in the air. This drying treatment can be carried out at a temperature from room temperature to 70 °C, for example, in the air and dried at 45 °C.

[0115] By going through the above processes, the aluminum powder product 1 (aluminum powder product 1 with a coating film) targeted in this embodiment can be obtained. That is, the manufactured aluminum powder product 1 has the following characteristics.

[0116] (1) The BET specific surface area is 0.16 m 2 / g or more.

[0117] (2) The phosphorus concentration of the entire aluminum powder product 1 is 1 × 10 -3 % by mass or more.

[0118] (3) In the photoelectron spectrum, the ratio of I P2s / ICl2p is 1.00 or more.

[0119] (4) Preferably D 50 is 15 μm or more and 45 μm or less.

[0120] (5) Preferably, the Hausner ratio is 1.14 or less.

[0121] (6) Preferably, the sphericity is 0.93 or more.

[0122] (7) Preferably, a high phosphorus concentration region 2a is present in a region where the depth from the outermost surface of the particle main body 2 is 30 nm or less.

[0123] The phosphorus concentration in the high phosphorus concentration region 2a is 3.5 times or more higher than the phosphorus concentration in the internal region where the depth from the outermost surface exceeds 30 nm and is 60 nm or less. The phosphoric acid-based compound is concentrated in the high phosphorus concentration region 2a. Further, the high phosphorus concentration region 2a is preferably present on the entire surface of the particle main body 2, but even if it is not completely formed on the entire surface, it may be in a state where it is formed on most of the surface.

[0124] The aforementioned aluminum powder product 1 can suppress the generation of hydrogen in hot water, and thus exhibits excellent corrosion resistance. The aluminum powder product 1 has sufficient corrosion resistance to water, and thus can be suitably used for a metal laminate molding process of an adhesive jetting method using an adhesive containing water described later.

[0125] If the aluminum powder product 1 satisfies the aforementioned particle size, in the case of a laminate of the aluminum powder product 1, the fluidity is good, and the packing density of the aluminum powder product layer can be stably obtained at a high level. Therefore, in the case of manufacturing a sintered body, a dense sintered body can be obtained.

[0126] Based on the analysis results of the examples described later, it can be inferred that the concentrated phosphorus exists as a phosphoric acid-based compound on the surface side of the particle main body 2, and it is also known that the particle size of the particle main body 2 hardly changes even after the aforementioned rust removal treatment and rust prevention treatment. Therefore, if it is the aforementioned aluminum powder product 1, the fluidity of the powder can be ensured by a simple method. Thus, a dense sintered body can be manufactured using the aluminum powder product 1. Since the aluminum powder product 1 has high fluidity, it is not likely to cause clogging in the flow path of a storage bin or a hopper.

[0127] Moreover, if it is the aforementioned aluminum powder product 1, the generation of hydrogen in hot water can be suppressed, so the corrosion resistance is improved, and even after the rust removal treatment and the rust prevention treatment, an appropriate particle size can be maintained. Therefore, a powder with high safety and good processability can be provided.

[0128] "Method for manufacturing an aluminum sintered body"

[0129] When manufacturing an aluminum sintered body (laminated object) using the aforementioned aluminum powder product 1, the aluminum powder product 1 is used as raw material powder (powder for metal laminated modeling), and a green compact is produced. The green compact is produced by a die forming method or a laminated modeling method. In the die forming method, the raw material powder is filled into a die having a specified shape to produce a green compact. In the laminated modeling method, the raw material powder is spread over a powder bed. A binder containing a thermosetting resin, a thermoplastic resin, or a photocurable resin is selectively sprayed onto the raw material powder to cure the raw material powder and produce a first modeling sheet. Then, the raw material powder is supplied to the powder bed, and the raw material powder is disposed on the first modeling sheet. The binder is selectively sprayed to cure the raw material powder, and a second modeling sheet is produced on the first modeling sheet. This operation is repeated, and multiple modeling sheets are laminated to produce a laminate.

[0130] In the laminated modeling method, a binder is selectively sprayed onto the raw material powder, and the raw material powder is cured to produce a modeling sheet. By repeating this operation and laminating multiple modeling sheets, a laminate can be formed. By repeatedly laminating the modeling sheets, the raw material powder is consolidated in a shape that conforms to a desired three-dimensional shape. After the raw material powder is consolidated, unnecessary raw material powder is removed or degreased as needed to obtain a green compact.

[0131] If a green compact is obtained, the green compact is placed in a heating furnace and heated to a temperature of about 560 to 650 °C for a required time in a vacuum atmosphere, a reducing atmosphere, an inert gas atmosphere, or a reduced-pressure gas flow atmosphere using a reducing gas or an inert gas without pressure for sintering.

[0132] As needed, the obtained sintered body is subjected to heat treatment, machining based on cutting tools, surface polishing, etc. for finishing, whereby a sintered body (laminated object) can be obtained.

[0133] Thus, for example, by using the aforementioned aluminum powder product 1, heat exchange components, conductive components, and strength components can be further enhanced in performance.

[0134] Examples

[0135] An aluminum base material (aluminum purity of 99.5% or more) or an A6061 aluminum alloy base material was put into a melting furnace to produce an aluminum melt or an aluminum alloy melt, and the aluminum powder products of Comparative Examples 1 to 4 in Table 1 below were produced from the melt by an inert gas atomization method.

[0136] Each of the aluminum powder products of Comparative Examples 1 to 4 was used as raw material powder, and the raw material powder was subjected to rust removal treatment and rust prevention treatment by the following steps.

[0137] 650 g of raw material powder and 300 mL of a rust remover (BF4-26 diluted twice: trade name of Tanimura Corporation) were put into a container and stirred at normal temperature and pressure. A mechanical stirrer was used for stirring at 350 rpm.

[0138] Stirring was carried out for 15 minutes, then 500 mL of pure water was added and left to stand, and the supernatant was removed in a state where the raw material powder had settled. This pure water was added to increase the total amount of the solution to facilitate the separation of the raw material powder from the rust remover solution.

[0139] Next, 100 mL of an antirust agent (BF4-16 diluted three times: trade name of Tanimura Corporation) was put into the container to neutralize the remaining rust remover. Pure water was added again and left to stand, and the supernatant was removed in a state where the powder had settled. In addition, the rust remover is an acidic agent and the antirust agent is a basic agent. Through this operation, the remaining rust remover does not act as an acid. Next, 300 mL of an antirust agent (BF4-16 diluted three times: trade name of Tanimura Corporation) was added and stirred with a stirring rod for about 1 minute, and an antirust film was formed on the surface of the particles of the raw material powder.

[0140] Pure water was added, the container was shaken and gently mixed and then left to stand, and then the supernatant was removed. This operation was carried out three times, and the raw material powder remaining in the container was collected and dried in a drying oven at 45 °C. The dried raw material powder was recovered and stored in a container together with silica gel. By performing rust removal treatment and antirust treatment on each aluminum powder product of Comparative Examples 1 to 4, the aluminum powder products of Examples 1 to 4 were obtained. Specifically, the aluminum powder product of Comparative Example 1 was used as the raw material powder to produce the aluminum powder product of Example 1. The aluminum powder product of Comparative Example 2 was used as the raw material powder to produce the aluminum powder product of Example 2. The aluminum powder product of Comparative Example 3 was used as the raw material powder to produce the aluminum powder product of Example 3. The aluminum alloy powder product of Comparative Example 4 was used as the raw material powder to produce the aluminum alloy powder product of Example 4.

[0141] The 50% cumulative average particle diameter (D 50 : μm), BET specific surface area (m 2 / g), sphericity (roundness), and Hausner ratio measurement results of the obtained aluminum powder products of Comparative Examples 1 to 4 and Examples 1 to 4 are shown in Table 1 below. And the P2p spectrum, P2s spectrum, and Cl2p spectrum of the obtained aluminum powder product were measured by XPS method. The cross-section of the particles was observed by TEM, and the concentration distribution of each element in the depth direction was measured by EDS method. The phosphorus concentration (mass %) in the whole powder was measured.

[0142] 〇"Measurement of Particle Size Distribution"

[0143] The particle size distribution was measured by the wet-based laser diffraction / scattering method using MT3300EXII manufactured by Microtrac Inc. Based on the obtained results, the 50% cumulative particle size on a volume basis was calculated as the average particle size.

[0144] 〇"Measurement of BET Specific Surface Area"

[0145] Using AUTOSORB-iQ2 manufactured by Quantachrome Instruments, the degassing treatment of the aluminum powder product was carried out at 200 °C for 60 minutes, and then the adsorption amount of krypton gas at 77.35 K was measured. The BET specific surface area was calculated based on the adsorption amount of krypton gas.

[0146] 〇"Measurement of Sphericity (Roundness)"

[0147] Using the dry image analyzer Morphologi4 manufactured by Malvern, for each sample, an aluminum powder product with a volume of 5 mm 3 was sprayed onto a glass plate, and images of 20,000 particles were taken with a microscope. The circularity was calculated based on the ratio of the circumference of a circle having the same area as the object projected from a single particle to the circumference of the object. Then, the average value of the circularities of 20,000 particles was obtained.

[0148] 〇"Measurement of Hausner Ratio"

[0149] Approximately 15 g of the aluminum powder product was weighed and poured into a 20 mL glass graduated cylinder. The volume of the aluminum powder product at this time was measured, and the bulk density was calculated based on this volume and the input amount. In this state, the bottom of the graduated cylinder was tapped and vibrated 150 times against the workbench for tapping compaction, and the volume of the aluminum powder product at this time was measured. The tapped density was calculated based on this volume and the input amount. The Hausner ratio was obtained by dividing the tapped density by the bulk density.

[0150] 〇"Measurement of Photoelectron Spectroscopy Based on XPS Method"

[0151] The aluminum powder product was sampled by embedding it in indium foil. Using AlKα rays (output 50 W) as the X-ray source through ULVAC-PHI PHI5000 VersaProbe II, the P2p spectrum, P2s spectrum, and Cl2p spectrum were measured.

[0152] 〇"Observation of Particle Cross Sections Based on TEM and Measurement of Concentration Distributions of Each Element in the Depth Direction Based on EDS Method"

[0153] Using the SMI3050 manufactured by Hitachi High-Tech Science Corporation, FIB processing was performed on the particles of the aluminum powder product at an acceleration voltage of 30 kV to fabricate a specimen for measuring the exposed particle cross-section. The particle cross-section was observed at an acceleration voltage of 200 kV using a transmission electron microscope Titan G2 80-200 manufactured by ThermoFisher Scientific. By the EDS method, the concentration distribution of each element in the depth direction was measured using a Super-X manufactured by Bruker Corporation.

[0154] 〇 "Measurement of phosphorus concentration in the whole powder product"

[0155] As follows, the phosphorus concentration in the whole aluminum powder product was measured by the molybdenum blue method. The aluminum powder product was dissolved in an acidic aqueous solution. An ammonium molybdate aqueous solution was added to the acidic aqueous solution to form a phosphomolybdic acid complex. The phosphomolybdic acid complex was extracted with an organic solvent and then reduced with a stannous chloride solution. Subsequently, the absorbance of the solution at a wavelength of 720 nm was measured, and the phosphorus concentration was calculated based on this absorbance.

[0156] [Table 1]

[0157]

[0158] As recorded in Table 1, the BET specific surface area of the aluminum powder products of Examples 1 to 4 was 0.16 m 2 / g or more, and the phosphorus concentration was 1×10 -3 mass% or more. Specifically, the BET specific surface area was 0.17 - 0.80 m 2 / g, the phosphorus concentration was 3×10 -3 -7×10 -3 mass%, the sphericity was 0.94 - 0.97, and the Hausner ratio was 1.09 - 1.23.

[0159] Moreover, regarding the BET specific surface area, Example 1 was greater than Comparative Example 1, Example 2 was greater than Comparative Example 2, Example 3 was greater than Comparative Example 3, and Example 4 was greater than Comparative Example 4. Regarding the median particle size D 50 , Example 1 was slightly smaller than Comparative Example 1, Example 2 was slightly smaller than Comparative Example 2, Example 3 was slightly smaller than Comparative Example 3, and Example 4 was slightly larger than Comparative Example 4.

[0160] From this, it can be seen that even if a raw material powder with a particle size suitable for applications such as laminated molding is fabricated and rust removal treatment and rust prevention treatment are performed on the raw material powder, the particle size suitable for laminated molding applications can be maintained. Therefore, the aluminum powder products of Examples 1 to 4 are suitable for laminated molding.

[0161] Figures 2A to 2HIt represents the concentration distribution in the depth direction of each element measured by energy dispersive X-ray spectroscopy (EDS method) in the particle cross-sections of the aluminum powder products in Examples 1 to 4 and Comparative Examples 1 to 4.

[0162] The EDS spectral intensity of Al decreases sharply near the surface of the particle. In Figures 2A to 2H , the minimum point of the EDS spectral intensity of Al is taken as the position of the outermost surface of the particle, and it is set as the zero point of the horizontal axis. The range of the horizontal axis of -30 nm or more and less than 0 nm is the outside of the particle.

[0163] As Figures 2A to 2H shown, as the depth from the outermost surface increases, the amount of Al (EDS spectral intensity of Al) gradually increases. In Comparative Examples 1 to 4, the amount of Al stabilizes at a depth exceeding 20 nm. In Examples 1 to 4, the amount of Al stabilizes at a depth exceeding 30 nm.

[0164] In Examples 1 to 4, the region up to a depth of 30 nm where the amount of Al gradually increases in the particle surface is considered to be the region (rust preventive film) where a coating film is formed under the influence of the rust remover and the rust preventive agent, and the region deeper than a depth of 30 nm is considered to be the internal region of the particle main body.

[0165] From Figures 2A to 2D the results shown, in the aluminum powder products of Examples 1 to 4, there is a high-concentration region of phosphorus in the region where the depth from the outermost surface is 30 nm or less, and the phosphorus concentration in the high-concentration region of phosphorus is more than 3.5 times higher than the average value of the phosphorus concentration in the internal region where the depth exceeds 30 nm and is 60 nm or less. In contrast, in Figures 2E to 2H the aluminum powder products of Comparative Examples 1 to 4 shown, no region where the phosphorus concentration is more than 3.5 times higher than the phosphorus concentration in the internal region was confirmed in the region from the outermost surface to a depth of 30 nm or less.

[0166] In the surface region where the depth from the outermost surface is 30 nm or less and the internal region where the depth exceeds 30 nm and is 60 nm or less in Examples 1 to 4 and Comparative Examples 1 to 4, the integral value of the EDS intensity ratio represented by the following formula (1) was calculated, and the ratio of the integral value of the EDS intensity ratio in the surface region to the integral value of the EDS intensity ratio in the internal region (the ratio of the phosphorus concentration in the surface region to the phosphorus concentration in the internal region) was calculated.

[0167] In the measurement of the concentration distribution in the depth direction of each element based on the EDS method (line analysis in the depth direction), the step size between measurement points is about 0.769 nm. Therefore, there are 39 measurement points in the depth direction length of 30 nm (30 / 0.769 = 39). The integral value of the EDS intensity ratio in formula (1) is the sum of the phosphorus concentrations (P / (C + N + O + F + Al + Si + P)) of 39 measurement points.

[0168] The obtained results are shown in Table 1.

[0169] It can be seen that, regarding the ratio of the phosphorus concentration in the surface region to the phosphorus concentration in the internal region, Examples 1 to 4 are greater than Comparative Examples 1 to 4. In Examples 1 to 4, phosphorus is concentrated in the surface region with a depth of 30 nm or less from the outermost surface.

[0170] In Comparative Examples 1 to 4, in the surface region from the outermost surface to a depth of 30 nm or less, the EDS spectral intensity of Al decreases sharply. Therefore, the value of the denominator of the phosphorus concentration (P / (C + N + O + F + Al + Si + P)) decreases sharply. As a result, in Comparative Examples 1 to 4, the integrated value of the EDS intensity ratio in the surface region is also larger than the integrated value of the EDS intensity ratio in the internal region.

[0171] [Mathematical formula 1]

[0172]

[0173] In Figure 3 the SEM image of the particle surface of Comparative Example 1 is shown, and in Figure 4 the SEM image of the particle surface of Example 1 is shown. From the comparison between Figure 3 and Figure 4 , it can be seen that a large number of fine irregularities are formed on the powder surface of Example 1. It is considered that the existence of these fine surface irregularities is the reason for the increase in the BET specific surface area of Examples 1 to 4 shown in Table 1.

[0174] Figures 5A to 8B Represents the photoelectron spectrum of the aluminum powder product based on X-ray photoelectron spectroscopy (XPS method).

[0175] Figure 5A , Figure 5B Represents the P2p spectrum, P2s spectrum, and Cl2p spectrum of Example 1 and Comparative Example 1. Figure 6A , Figure 6B Represents the P2p spectrum, P2s spectrum, and Cl2p spectrum of Example 2 and Comparative Example 2. Figure 7A , Figure 7B Represents the P2p spectrum, P2s spectrum, and Cl2p spectrum of Example 3 and Comparative Example 3. Figure 8A , Figure 8B Represents the P2p spectrum, P2s spectrum, and Cl2p spectrum of Example 4 and Comparative Example 4.

[0176] In Figure 5A , Figure 5B the photoelectron spectrum of Comparative Example 1 shown, a broad peak is observed in the energy range of the P2p spectrum, but no distinct peak is observed in the energy range of the P2s spectrum. Thus, it is considered that Figure 5BThe peak of Comparative Example 1 shown is not derived from phosphorus species, but is a satellite peak of Al.

[0177] In Figure 5A , Figure 5B In the photoelectron spectrum of Example 1 shown, a distinct peak (191.5 eV) exists within the energy range of the P2s spectrum. Therefore, the peaks observed within the energy range of the P2p spectrum are also considered to have contributions from phosphorus species. According to Figure 5A , Figure 5B the positions of the P2s peak and P2p peak shown, it can be inferred that phosphorus does not exist as a monomer or alloy species, but rather as a phosphoric acid-based compound (oxoacid of phosphorus) in the region near the surface.

[0178] In Figures 6A to 8B the P2s peaks and P2p peaks of the photoelectron spectra of Examples 2 to 4 shown, the same tendency is also observed.

[0179] In addition, in Figures 5A to 8B the photoelectron spectrum shown, the detected intensity (count) of the baseline (background) is around 1000 to 3000. The detected intensity (count) at the peak top of the P2s peak and P2p peak is a value around +400 from the baseline. Therefore, the detected intensities (counts) of the P2s peak, P2p peak, and Cl2p peak do not deviate significantly from the detected intensity (count) of the baseline. Thus, as shown in Table 1, the ratio I P2s of the P2s peak intensity to the Cl2p peak intensity I Cl2p becomes a value around 1. P2s / I Cl2p

[0180] If the results of Figures 2A to 2H , Figures 5A to 8B are analyzed, the following can be known.

[0181] (1) The aluminum powder products of Examples 1 to 4 have a high-concentration region of phosphorus in the region with a depth of 30 nm or less from the outermost surface.

[0182] (2) The phosphorus concentration in the high-concentration region of phosphorus is more than 3.5 times higher than that in the internal region with a depth exceeding 30 nm and 60 nm or less from the outermost surface.

[0183] (3) Phosphoric acid-based compounds are concentrated in the high-concentration region of phosphorus.

[0184] For example, according to Figure 2A the measurement results, in Example 1, the high-concentration region of phosphorus exists in the region with a depth of 30 nm or less from the outermost surface of the particles.

[0185] Moreover, in Examples 1 to 4, the P2s peak intensity I P2sThe ratio I of the intensity of the Cl2p peak at 199.0 eV Cl2p is P2s / I Cl2p is 1.00 or more. In contrast, the ratios I P2s / I Cl2p of Comparative Examples 1 to 4 are less than 1.00. Specifically, the I P2s / I Cl2p of Examples 1 to 4 in Table 1 are 1.04 to 1.23. In contrast, the I P2s / I Cl2p of Comparative Examples 1 to 4 are 0.943 to 0.976.

[0186] Industrial Applicability

[0187] The aluminum powder product of the present embodiment is suitable as a raw material powder for metal laminated molding.

[0188] Symbol Explanation

[0189] 1 - Aluminum powder product; 2 - Particle main body; 2a - High concentration region.

Claims

1. An aluminum powder product, characterized in that, The BET specific surface area of the powder product is 0.16 m 2 / g or more, and the phosphorus concentration of the whole powder product measured by the molybdenum blue method is 1×10 -3 mass% or more, and in the photoelectron spectrum of the powder product measured by X-ray photoelectron spectroscopy, i.e., XPS method, the intensity I of the P2s peak at 191.5 eV P2s and the intensity I of the Cl2p peak at 199.0 eV Cl2p The ratio I P2s / I Cl2p is 1.00 or more.

2. The aluminum powder product according to claim 1, wherein, a high-concentration region of phosphorus exists in a region where the depth from the outermost surface of the particles constituting the powder product is 30 nm or less, and the phosphorus concentration in the high-concentration region of phosphorus is 3.5 times or more higher than the phosphorus concentration in a region where the depth from the outermost surface of the particles exceeds 30 nm, and a phosphoric acid-based compound is concentrated in the high-concentration region of phosphorus.

3. The aluminum powder product according to claim 1 or 2, characterized in that, The median particle size D, which is the 50% cumulative particle size of the volume reference measured by the laser diffraction / scattering method 50 is 15 μm or more and 45 μm or less, and the Hausner ratio of the powder product is 1.14 or less.

4. The aluminum powder product according to claim 1 or 2, characterized in that, the sphericity measured by the image analysis method is 0.93 or more.

5. The aluminum powder product according to claim 3, characterized in that, the sphericity measured by the image analysis method is 0.93 or more.

6. The aluminum powder product according to claim 1 or 2, characterized in that, The aluminum powder product is used for layered manufacturing.

7. The aluminum powder product according to claim 3, characterized in that, The aluminum powder product is used for layered manufacturing.

8. The aluminum powder product according to claim 4, characterized in that, The aluminum powder product is used for layered manufacturing.

9. The aluminum powder product according to claim 5, wherein, The aluminum powder product is used for layered manufacturing.

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