Aluminum-containing particles

Abstract

Provided are aluminum-containing particles, wherein: a D50 particle size calculated by the following <particle size measurement> is 30.0 μm to 60.0 μm; a value obtained by dividing a D90 particle size by a D10 particle size is 1.5 to 3.5, the D90 particle size and the D10 particle size being calculated by the following <particle size measurement>; and an apparent density is 1.35 g / cm3 or more as measured in accordance with JIS Z 2504:2020 using a funnel angle of 60° and an orifice with a diameter of 5.0 mm. <Particle size measurement> 3.0 g of aluminum-containing particles are mixed with 40 mL of water and 10 mL of a 1.3% concentration surfactant, and a mixed liquid dispersed in a ultrasonic bath for 300 seconds is used as a measurement sample. Using a laser diffraction / scattering particle size analyzer, the volume-based particle size distribution of the aluminum-containing particles is measured, and the values of the D10 particle size, D50 particle size, and D90 particle size are obtained, respectively.

Description

Aluminum-containing particles

[0001] The present invention relates to aluminum-containing particles.

[0002] As a technique relating to aluminum-containing particles, for example, the technique described in Patent Document 1 is known.

[0003] Patent Document 1 describes particles containing an aluminum alloy, which are substantially spherical in the state of primary particles and have a composition M ｘ Al ｙ and M ｚ Al ｗ where M is a metal other than Al, 0<x<1, 0<y<1, 0<z<1, 0<w<1, x / y≧1, z / w<1, x+y=1, z+w=1, and the aluminum content is in the range of 8% by mass to 50% by mass. Patent Document 1 discloses that particles having a mixed phase of two types of aluminum alloys can be provided in the form of primary particles.

[0004] JP 2022-89673 A

[0005] The present invention provides aluminum-containing particles with improved flowability.

[0006] According to the present invention, there are provided the following aluminum-containing particles.

[0007] [1] D calculated by the following <Particle size measurement> ５０ The particle diameter is 30.0 μm or more and 60.0 μm or less, and D calculated by the following <Particle diameter measurement> ９０ The particle diameter is D １０ The value divided by the particle diameter is 1.5 or more and 3.5 or less, and the apparent density measured in accordance with JIS Z 2504:2020 using a funnel angle of 60° and an orifice with a diameter of 5.0 mm is 1.35 g / cm ３<Particle size measurement> 3.0 g of aluminum-containing particles were mixed with 40 mL of water and 10 mL of a surfactant having a concentration of 1.3%, and the mixture was dispersed in an ultrasonic bath for 300 seconds to obtain a measurement sample. The volume-based particle size distribution of the aluminum-containing particles was measured using a laser diffraction / scattering particle size measurement device, and D １０ Particle diameter, D ５０ Particle diameter, and D ９０ [2] The particle diameter values ​​calculated by the above <Particle diameter measurement> are obtained. １０ [3] The aluminum-containing particles according to [1], having a particle diameter of 20.0 μm or more and 40.0 μm or less. ９０The aluminum-containing particles according to [1] or [2], having a particle diameter of 50.0 μm or more and 100.0 μm or less. [4] The aluminum-containing particles according to any one of [1] to [3], having a sphericity of 0.8 or more. [5] The aluminum-containing particles according to any one of [1] to [4], having a flowability of 15.0 sec / 50 g or less in a hole flow test measured in accordance with JIS Z2502:2020. [6] The aluminum-containing particles according to any one of [1] to [5], comprising at least one particle selected from the group consisting of pure aluminum particles and aluminum-based alloy particles. [7] The aluminum-containing particles according to [6], comprising at least one element selected from the group consisting of Cu, Mn, Si, Mg, Zn, and Ni. [8] The aluminum-containing particle according to [6] or [7], wherein the aluminum-based alloy particle comprises at least one selected from the group consisting of an Al-Si-based alloy, an Al-Cu-based alloy, an Al-Mn-based alloy, an Al-Mg-based alloy, an Al-Si-Mg-based alloy, an Al-Si-Cu-based alloy, an Al-Zn-Mg-based alloy, an Al-Si-Mg-Cu-based alloy, an Al-Cu-Ni-Mg-based alloy, and an Al-Zn-Mg-Cu-based alloy. [9] The aluminum-containing particle according to any one of [6] to [8], wherein the aluminum-based alloy particle comprises at least one selected from the group consisting of AlSi10Mg and AlSi12.

[10] The aluminum-containing particle according to any one of [1] to [9], wherein the aluminum-based alloy particle is usable as a raw material powder for a 3D printer object.

[0008] According to the present invention, it is possible to provide aluminum-containing particles having improved fluidity.

[0009] Hereinafter, embodiments of the present invention will be described. Unless otherwise specified, the numerical range "A to B" represents A or more and B or less.

[0010] [Aluminum-containing particles] The aluminum-containing particles of the present embodiment are D ５０ The particle diameter is 30.0 μm or more and 60.0 μm or less, and D ９０ The particle diameter is D １０The value divided by the particle diameter is 1.5 or more and 3.5 or less, and the apparent density measured in accordance with JIS Z 2504:2020 using a funnel angle of 60° and an orifice with a diameter of 5.0 mm is 1.35 g / cm ３ That's all.

[0011] The aluminum-containing particles are used, for example, as a raw material powder for objects molded by 3D printers, a brazing paste powder, etc. The raw material powder for objects molded by 3D printers is required to improve the mechanical strength and molding accuracy of the resulting objects.

[0012] The present inventors have found that a decrease in powder fluidity may result in the powder not being dense during modeling using a 3D printer, which may reduce the mechanical strength of the resulting model. The present inventors have also found that a decrease in powder fluidity may result in reduced modeling accuracy due to the occurrence of defects inside the resulting model and the manifestation of unevenness on the surface of the resulting model. That is, the present inventors have considered that improving the powder fluidity may improve the mechanical strength and modeling accuracy of the model.

[0013] The present inventors have conducted extensive research to obtain aluminum-containing particles with improved fluidity. As a result, the present inventors have found that the D ５０ Particle diameter, D ９０ The particle diameter is D １０ It has been found that the fluidity of the aluminum-containing particles is improved by setting the value obtained by dividing the apparent density by the particle diameter and the apparent density within specific ranges. ５０ Particle diameter, D ９０ The particle diameter is D １０ It has been found that the value obtained by dividing by the particle diameter and the apparent density are effective design indicators for improving the fluidity of aluminum-containing particles. That is, the aluminum-containing particles of the present invention have improved fluidity. Furthermore, the aluminum-containing particles of the present invention can improve the mechanical strength and molding accuracy of objects molded using a 3D printer.

[0014] D of the aluminum-containing particles of this embodiment５０ The particle diameter is 30.0 μm or more and 60.0 μm or less. ５０ From the viewpoint of further improving the flowability, the particle size is preferably 32.0 μm or more and 55.0 μm or less, more preferably 34.0 μm or more and 53.0 μm or less, and even more preferably 36.0 μm or more and 50.0 μm or less.

[0015] D of the aluminum-containing particles of this embodiment １０ From the viewpoint of further improving the flowability, the particle size is preferably 20.0 μm or more and 40.0 μm or less, more preferably 22.0 μm or more and 37.0 μm or less, and even more preferably 25.0 μm or more and 35.0 μm or less.

[0016] D of the aluminum-containing particles of this embodiment ９０ From the viewpoint of further improving fluidity, the particle size is preferably 50.0 μm or more and 100.0 μm or less, more preferably 52.0 μm or more and 90.0 μm or less, and even more preferably 54.0 μm or more and 85.0 μm or less.

[0017] D of the aluminum-containing particles of this embodiment ９０ The particle diameter is D １０ The value obtained by dividing the D by the particle diameter is 1.5 or more and 3.5 or less. ９０ The particle diameter is D １０ The value divided by the particle diameter is preferably 1.6 or more and 3.2 or less, more preferably 1.6 or more and 3.0 or less, even more preferably 1.6 or more and 2.9 or less, even more preferably 1.7 or more and 2.8 or less, and even more preferably 1.8 or more and 2.7 or less.

[0018] Here, D of the aluminum-containing particles １０ Particle diameter, D ５０ Particle diameter, and D ９０ The particle diameters refer to values ​​calculated by the <Particle diameter measurement> below.

[0019] <Particle size measurement> 3.0 g of aluminum-containing particles were mixed with 40 mL of water and 10 mL of a surfactant with a concentration of 1.3%, and the mixture was dispersed in an ultrasonic bath for 300 seconds to obtain a measurement sample. The volume-based particle size distribution of the aluminum-containing particles was measured using a laser diffraction / scattering particle size measuring device, and D １０ Particle diameter, D ５０ Particle diameter, and D ９０ The particle diameter values ​​are obtained. Here, for example, an aqueous solution obtained by diluting the original solution of Fresh Green Apple with Fruit Acid (manufactured by Rocket Soap Co., Ltd.) 11 times can be used as the 1.3% surfactant. The surfactant is, for example, linear alkylbenzenesulfonate sodium.

[0020] The particle diameter of the aluminum-containing particles can be adjusted to a desired value, for example, by adjusting the classification conditions when producing the aluminum-containing particles, specifically, by adjusting the opening diameter of the sieve mesh when classifying the aluminum-containing particles.

[0021] The apparent density of the aluminum-containing particles of this embodiment is 1.35 g / cm ３ The apparent density of the aluminum-containing particles of the present embodiment is preferably 1.36 g / cm from the viewpoint of further improving fluidity. ３ More preferably, 1.37 g / cm ３ More preferably, 1.38 g / cm ３ The upper limit is not particularly limited, but is, for example, 1.48 g / cm ３ or less, 1.46 g / cm ３ In addition, the apparent density of the aluminum-containing particles of the present embodiment may be preferably 1.36 g / cm or less from the viewpoint of further improving fluidity. ３ 1.48g / cm or more ３ or less, more preferably 1.37 g / cm ３ 1.48g / cm or more ３ More preferably, 1.38 g / cm or less ３ 1.46g / cm or more ３The apparent density of the aluminum-containing particles means a value measured in accordance with JIS Z 2504:2020 using an orifice with a diameter of 5.0 mm and a funnel angle of 60°.

[0022] The apparent density of the aluminum-containing particles of this embodiment can be adjusted to a desired value, for example, by adjusting the production conditions when producing the aluminum-containing particles by an atomization method, specifically, by adjusting the amount of molten metal being discharged; by adjusting the oxygen concentration in the atmosphere; by adjusting the opening diameter of the upper screen and the opening diameter of the lower screen in step (C) described below; etc.

[0023] The sphericity of the aluminum-containing particles of this embodiment is preferably 0.8 or more, more preferably 0.85 or more, and even more preferably 0.9 or more. The sphericity of the aluminum-containing particles means a value calculated by image analysis of images obtained with a scanning electron microscope, and specifically means a value calculated by measuring the minor axis length and major axis length of the aluminum-containing particles, determining the sphericity of one aluminum-containing particle using the formula sphericity = minor axis length / major axis length, and arithmetically averaging the sphericities of 100 or more aluminum-containing particles.

[0024] The fluidity of the aluminum-containing particles of this embodiment measured in accordance with JIS Z2502:2020 by a Hall Flow test is preferably 15.0 sec / 50g or less, more preferably 13.0 sec / 50g or less, and even more preferably 11.0 sec / 50g or less, from the viewpoint of further improving the fluidity. The lower limit is not particularly limited, but may be, for example, 5.0 sec / 50g or more, or 7.0 sec / 50g or more. The fluidity of the aluminum-containing particles measured in accordance with the Hall Flow test means the time it takes for 50g of aluminum-containing particles to flow through an orifice of a funnel calibrated to specified dimensions, measured in accordance with JIS Z2502:2020. In this specification, the fluidity of the aluminum-containing particles measured in accordance with the Hall Flow test can be determined by measuring the flow time of the aluminum-containing particles twice and averaging the two measured values. Furthermore, when two measurements are performed and a measurement value is obtained in one but not in the other, the fluidity of the aluminum-containing particles measured by the Hall flow test may be the obtained measurement value.

[0025] The aluminum-containing particles of this embodiment are not particularly limited as long as they contain aluminum (Al), but preferably include at least one selected from the group consisting of pure aluminum particles and aluminum-based alloy particles, and more preferably include aluminum-based alloy particles. Here, pure aluminum particles refer to particles made of aluminum with a purity of 99.00% or more (so-called 1000-series aluminum). Furthermore, aluminum-based alloy particles refer to aluminum alloys containing Al as a main component.

[0026] The aluminum-based alloy particles of this embodiment preferably contain at least one element selected from the group consisting of Cu, Mn, Si, Mg, Zn, and Ni, and more preferably contain at least one element selected from the group consisting of Si and Mg. When the aluminum-based alloy particles of this embodiment contain Si, the Si content in the aluminum-based alloy particles is preferably 7.00% by mass to 15.00% by mass, more preferably 8.00% by mass to 14.00% by mass, and even more preferably 9.00% by mass to 11.00% by mass. When the aluminum-based alloy particles of this embodiment contain Mg, the Mg content in the aluminum-based alloy particles is preferably 0.10% by mass to 0.60% by mass, more preferably 0.20% by mass to 0.45% by mass, when the aluminum-based alloy particles are taken as 100.00% by mass. The contents of other elements are not particularly limited and may be set to appropriate amounts. The content of each element can be determined by elemental analysis using, for example, solid state emission spectrometry.

[0027] The aluminum-based alloy particles of this embodiment preferably contain at least one selected from the group consisting of Al-Si-based alloys, Al-Cu-based alloys, Al-Mn-based alloys, Al-Mg-based alloys, Al-Si-Mg-based alloys, Al-Si-Cu-based alloys, Al-Zn-Mg-based alloys, Al-Si-Mg-Cu-based alloys, Al-Cu-Ni-Mg-based alloys, and Al-Zn-Mg-Cu-based alloys, and more preferably contain at least one selected from the group consisting of Al-Si-based alloys and Al-Si-Mg-based alloys.

[0028] The composition of the aluminum-based alloy particles of this embodiment is not particularly limited and may be, for example, any composition selected from the group consisting of aluminum alloys for rolling, aluminum alloys for casting, and aluminum alloys for die casting, but is preferably the composition of an aluminum alloy for casting, for example, the composition specified in JIS H2211:2010.

[0029] The aluminum-based alloy particles of this embodiment preferably contain at least one selected from the group consisting of AlSi10Mg and AlSi12, and more preferably contain AlSi10Mg. Here, AlSi10Mg and AlSi12 refer to alloys that satisfy the composition specified in JIS H2211:2010.

[0030] [Uses of Aluminum-Containing Particles] The uses of the aluminum-containing particles of this embodiment are not particularly limited. The aluminum-containing particles of this embodiment are, for example, aluminum-containing particles that can be used for at least one selected from the group consisting of raw material powder for a 3D printer model and a brazing paste powder, and are preferably aluminum-containing particles that can be used for a raw material powder for a 3D printer model.

[0031] [Method for producing aluminum-containing particles] A preferred embodiment of the method for producing aluminum-containing particles of this embodiment will be described.

[0032] The method for producing aluminum-containing particles of the present embodiment preferably includes a step (A) of obtaining aluminum-containing particles (a) by a disk atomization method, a step (B) of classifying the aluminum-containing particles (a) to obtain aluminum-containing particles (b), and a step (C) of classifying the aluminum-containing particles (b) after the step (B).

[0033] Hereinafter, each step in the method for producing aluminum-containing particles according to this embodiment will be described.

[0034] <Molten Metal Preparing Step> The method for producing aluminum-containing particles of the present embodiment preferably includes, prior to step (A), a step of preparing a molten metal that serves as a raw material for the aluminum-containing particles.

[0035] The method for preparing the molten metal is not particularly limited, and examples thereof include a method in which an aluminum alloy base metal is charged into a primary furnace and heated; a method in which an aluminum base metal and each element are charged into a primary furnace and heated so as to obtain a target composition of aluminum-containing particles; and the like. The molten metal of this embodiment may also contain a flux. Examples of the flux include a mixture of a chlorine compound (NaCl.KCl) and a fluorine compound (NaF.Na２ SiF ６ ) and a mixed salt thereof, etc., can be used. The content of the flux in the molten metal in this embodiment may be, for example, 0.1 parts by mass or more and 1 part by mass or less, or 0.2 parts by mass or more and 0.3 parts by mass or less, when the aluminum alloy base metal (or the total of the aluminum base metal and each element) is taken as 100 parts by mass.

[0036] The heating temperature when preparing the molten metal is not particularly limited, and may be appropriately adjusted taking into consideration the melting point of aluminum or the melting point of the aluminum-based alloy (or the melting point of the aluminum-based alloy derived from the composition of the target aluminum-containing particles). When the aluminum-containing particles of the present embodiment contain AlSi10Mg, the heating temperature is preferably 700°C or higher and 900°C or lower, more preferably 800°C or higher and 850°C or lower.

[0037] The molten metal obtained in the primary furnace may be transferred to a secondary furnace, and the molten metal may be held in the secondary furnace. The temperature at which the molten metal is held is not particularly limited and may be appropriately adjusted taking into account the melting point of aluminum or the melting point of the aluminum-based alloy (or the melting point of the aluminum-based alloy derived from the composition of the target aluminum-containing particles). When the aluminum-containing particles of this embodiment contain AlSi10Mg, the holding temperature is preferably 600°C or higher and 900°C or lower, more preferably 650°C or higher and 800°C or lower.

[0038] The primary furnace and the secondary furnace are not particularly limited as long as they are melting furnaces that can be used to produce molten metal, and for example, electric furnaces, high-frequency induction furnaces, etc. can be used.

[0039] <Step (A)> The method for producing aluminum-containing particles of the present embodiment preferably includes a step (A) of obtaining aluminum-containing particles (a) by disk atomization.

[0040] In step (A), the diameter of the rotating disc is not particularly limited, but is preferably φ30 mm or more and φ40 mm or less. In step (A), the rotation speed of the rotating disc is preferably 70,000 rpm or more and 90,000 rpm or less, more preferably 75,000 rpm or more and 85,000 rpm or less.

[0041] In step (A), the tapping rate of the molten metal is preferably 20 kg / h or more and 50 kg / h or less, more preferably 25 kg / h or more and 40 kg / h or less, and more preferably 25 kg / h or more and 37 kg / h or less. When the tapping rate of the molten metal is equal to or more than the above-mentioned lower limit, the production amount per unit time can be improved. When the tapping rate of the molten metal is equal to or less than the above-mentioned upper limit, the proportion of coarse particles in the aluminum-containing particles (a) can be reduced, thereby improving the classification yield. When the tapping rate of the molten metal is within the above-mentioned range, the apparent density of the aluminum-containing particles can be further improved. The tapping rate of the molten metal can be adjusted, for example, by adjusting the nozzle diameter of the secondary furnace.

[0042] The oxygen concentration in the atmosphere in step (A) is preferably 500 ppm or less, more preferably 100 ppm or less, even more preferably 50 ppm or less, and even more preferably 30 ppm or less, from the viewpoint of further improving the apparent density of the aluminum-containing particles and from the viewpoint of improving the sphericity of the aluminum-containing particles.

[0043] The type of disk atomizer used in step (A) is not particularly limited, but for example, a spherical powder manufacturing device (manufactured by Minerva Kiki Co., Ltd.) can be used.

[0044] <Step (B)> The method for producing aluminum-containing particles of the present embodiment preferably includes step (B) of classifying the aluminum-containing particles (a) to obtain aluminum-containing particles (b). Step (B) is a step performed after step (A). An optional step may be included between step (A) and step (B).

[0045] Step (B) is preferably a step of removing coarse particles from aluminum-containing particles (a) to obtain aluminum-containing particles (b), and more specifically, it is a step of sieving aluminum-containing particles (a) using a sieve and recovering aluminum-containing particles (a) that have passed through the sieve to obtain aluminum-containing particles (b). Here, the opening diameter of the sieve is, for example, 200 μm or more and 300 μm or less, and preferably 250 μm.

[0046] The classifier used in step (B) is not particularly limited, but for example, a vibrating sieve with an ultrasonic oscillator (manufactured by Koei Sangyo Co., Ltd.) can be used.

[0047] <Stirring Step> The method for producing aluminum-containing particles of the present embodiment preferably includes a step of stirring the aluminum-containing particles (b) between step (B) and step (C).

[0048] The method for stirring the aluminum-containing particles (b) is not particularly limited, but examples thereof include a method for stirring the aluminum-containing particles (b) using a mixer. As the mixer, for example, an infinite mixer (manufactured by Tokuju Industries Co., Ltd.) can be used.

[0049] <Step (C)> The method for producing aluminum-containing particles of the present embodiment preferably includes step (C) of classifying the aluminum-containing particles (b). Step (C) is a step performed after step (B). An optional step may be included between step (B) and step (C).

[0050] In step (C), the method for classifying the aluminum-containing particles (b) is not particularly limited. Step (C) may be, for example, a step of removing coarse particles and fine powder from the aluminum-containing particles (b), a step of removing only coarse particles from the aluminum-containing particles (b), or a step of removing only fine powder from the aluminum-containing particles (b).

[0051] Step (C) is, for example, a step of sieving the aluminum-containing particles (b) using an upper screen and a lower screen as sieves, and recovering the aluminum-containing particles (b) that passed through the upper screen but did not pass through the lower screen, thereby classifying the aluminum-containing particles (b). Step (C) may also be, for example, a step of sieving the aluminum-containing particles (b) using only the upper screen as sieves, and recovering the aluminum-containing particles (b) that passed through the upper screen, thereby classifying the aluminum-containing particles (b), or a step of sieving the aluminum-containing particles (b) using only the lower screen as sieves, and recovering the aluminum-containing particles (b) that did not pass through the lower screen, thereby classifying the aluminum-containing particles (b).

[0052] The opening diameter of the upper screen is, for example, 40 μm to 180 μm, preferably 50 μm to 170 μm. The opening diameter of the lower screen is, for example, 5 μm to 30 μm, preferably 10 μm to 20 μm. By appropriately adjusting the opening diameters of the upper screen and the lower screen, the particle diameter of the aluminum-containing particles can be adjusted to a desired value.

[0053] The classifier used in step (C) is not particularly limited, but for example, a Hibolter (blow-through type classifier manufactured by Toyo Hightec Co., Ltd.) can be used.

[0054] <Other Steps> The method for producing aluminum-containing particles of the present embodiment may include other steps in addition to the steps described above.

[0055] The aluminum-containing particles of the present embodiment may be aluminum-containing particles obtained after step (C) in the method for producing aluminum-containing particles, or may be aluminum-containing particles (a) or aluminum-containing particles (b) obtained before step (C). However, from the viewpoint of adjusting the particle diameter to an appropriate range, aluminum-containing particles obtained after step (C) are preferred.

[0056] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations may be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention.

[0057] The present embodiment will be described in detail below based on examples and comparative examples, but the present embodiment is not limited to the descriptions of these examples.

[0058] [Example 1] <Molten Metal Preparation Step> Aluminum alloy base metal (AlSi10Mg) was charged into a primary furnace (electric furnace manufactured by Ducor Corporation), and flux (product name: Tsubasa Flux Smokeless manufactured by Tokyo Molex Crucible Co., Ltd.) was further added in an amount of 0.2 parts by mass per 100 parts by mass of the aluminum alloy base metal. The mixture was then heated at 830°C to prepare a molten metal. The obtained molten metal was transferred from the primary furnace to a secondary furnace (high-frequency induction furnace manufactured by High Frequency Systems Co., Ltd.). The molten metal was maintained at a temperature of 700°C in the secondary furnace.

[0059] <Atomization step (step (A))> Using the molten metal in the secondary furnace as a raw material, aluminum-containing particles (a) were obtained by a disk atomization method under the following conditions: Disk atomization device: spherical powder manufacturing device (manufactured by Minerva Kiki Co., Ltd.) Rotating disk diameter: φ35 mm Rotation speed: 82,000 rpm Melt output rate: 34 kg / h Secondary furnace nozzle diameter: φ2 mm Oxygen concentration: 30 ppm or less

[0060] Here, the oxygen concentration refers to the oxygen concentration in the spray chamber, and is the value measured using an oxygen concentration meter (manufactured by Toray Engineering Co., Ltd., product name: zirconia oxygen concentration meter RF-30). The oxygen concentration was adjusted to the target oxygen concentration by appropriately injecting compressed air or nitrogen gas into the spray chamber.

[0061] <First Classification Step (Step (B))> The aluminum-containing particles (a) were classified using a vibrating sieve (manufactured by Koei Sangyo Co., Ltd., product name: ultrasonic oscillator-equipped vibrating sieve UB70UR-3S, sieve mesh opening diameter: 250 μm) to obtain aluminum-containing particles (b). Here, the aluminum-containing particles (a) that passed through the sieve mesh were collected and designated as aluminum-containing particles (b).

[0062] <Stirring Step> The aluminum-containing particles (b) were stirred using a mixer (manufactured by Tokuju Kogyosho Co., Ltd., product name: Infinite Mixer MM-220) at 29 rpm for 5 minutes.

[0063] Using a solid-state optical emission analyzer (manufactured by Thermo Fischer SCIENTIFIC, product name: ARL-3460), elemental analysis of the mixed aluminum-containing particles (b) was performed by solid-state optical emission spectrometry. As a result of the elemental analysis, the composition of the aluminum-containing particles (b) was an alloy represented by AlSi10Mg.

[0064] <Second Classification Step (Step (C))> The aluminum-containing particles (b) were classified using a blow-through classifier (manufactured by Toyo Hightec Co., Ltd., product name: Hibolter NR-600SD type (two-stage)) to obtain the aluminum-containing particles of Example 1. Here, instead of using the upper screen in Example 1, a lower screen (opening diameter: vertical 10 μm, horizontal 10 μm) was used, and the aluminum-containing particles (b) that did not pass through the lower screen were collected and used as the aluminum-containing particles of Example 1.

[0065] [Examples 2 to 20 and Comparative Examples 3 to 5] The aluminum-containing particles of Examples 2 to 20 and Comparative Examples 3 to 5 were obtained by the same method as in Example 1, except that the conditions were as shown in Table 1 and the aluminum-containing particles (b) recovered in the second classification step were as follows.

[0066] In the second classification step in Examples 2 to 20 and Comparative Examples 3 to 5, aluminum-containing particles (b) that passed through the upper screen but not the lower screen were collected and designated as aluminum-containing particles. Here, in the case where the upper screen was not used, aluminum-containing particles (b) that did not pass through the lower screen were collected and designated as aluminum-containing particles. In addition, in the case where the lower screen was not used, aluminum-containing particles (b) that passed through the upper screen were collected and designated as aluminum-containing particles.

[0067] [Comparative Examples 1 and 2] The aluminum-containing particles of Comparative Examples 1 and 2 were obtained by the same method as in Example 1, except that the conditions were as shown in Table 1 and the aluminum-containing particles (b) recovered in the second classification step were as follows.

[0068] In the second classification step in Comparative Examples 1 and 2, the aluminum-containing particles (b) that passed through the upper and lower screens were collected and used as aluminum-containing particles.

[0069] In Table 1, "Flux" indicates whether or not flux was added in the molten metal preparation process. Furthermore, in Table 1, the values ​​listed under "Upper Screen" and "Lower Screen" refer to the opening diameter of the screen of the classifier in the second classification process. Levels where the values ​​listed under "Upper Screen" and "Lower Screen" are "-" indicate that the upper or lower screen was not used.

[0070] The aluminum-containing particles (b) of Examples 2 to 20 and Comparative Examples 1 to 5 were subjected to elemental analysis in the same manner as in Example 1, and it was confirmed that all of them were alloys represented by AlSi10Mg.

[0071] [Measurements] The following measurements were carried out on the aluminum-containing particles of Examples 1 to 20 and Comparative Examples 1 to 5. The measurement results are shown in Table 2.

[0072] <Sphericity> First, an observation sample was prepared in which 100 or more aluminum-containing particles were fixed to the surface of a base. Here, the aluminum-containing particles in the observation sample were dispersed so that they did not overlap with each other. Specifically, the observation sample was prepared by placing double-sided tape on the surface of the base, dropping aluminum-containing particles onto the exposed surface of the double-sided tape, and removing excess aluminum-containing particles with air. Next, using a scanning electron microscope (manufactured by Hitachi High-Tech Corporation, product name: SU8200), the observation sample was magnified 500 times to obtain an SEM image. At least 20 SEM images were obtained for each level while shifting the imaging position. The obtained SEM images were analyzed using ImageJ to determine the sphericity of the aluminum-containing particles of Examples 1 to 20 and Comparative Examples 1 to 5. Specifically, the minor axis length and major axis length of the aluminum-containing particle were measured, and the sphericity of one aluminum-containing particle was determined using the formula: sphericity = minor axis length / major axis length. The sphericity of 100 or more aluminum-containing particles was calculated as an arithmetic average. The sphericity of the aluminum-containing particles of Examples 1 to 20 and Comparative Examples 1 to 5 was 0.8 or more.

[0073] <Particle size> 3.0 g of aluminum-containing particles were mixed with 40 mL of water and 10 mL of a 1.3% surfactant, and the mixture was dispersed in an ultrasonic bath for 300 seconds to prepare a measurement sample. Here, the 1.3% surfactant was prepared by diluting a stock solution of Fresh Green Apple with Fruit Acid (manufactured by Rocket Soap Co., Ltd., surfactant (linear alkylbenzene sulfonate sodium) 14%) 11 times. Specifically, a 1.3% surfactant was prepared by diluting 50 mL of the stock solution of Fresh Green Apple with Fruit Acid with 500 mL of water. The volume-based particle size distribution of the aluminum-containing particles was measured for the measurement sample using a laser diffraction / scattering particle size analyzer (manufactured by Microtrac, product name: MT-3300EX II), and the D １０ Particle diameter, D ５０ Particle diameter, and D ９０ The particle size values ​​were obtained. １０ Particle size and D９０ From the particle diameter value, D ９０ The particle diameter is D １０ The value divided by the particle diameter (D ９０ / D １０ ) was calculated.

[0074] <Apparent Density> The apparent density was measured using an orifice with a funnel angle of 60° and a diameter of 5.0 mm in accordance with JIS Z 2504:2020.

[0075] <Fluidity> Fluidity was measured by a hole flow test in accordance with JIS Z2502:2020. That is, the time [sec / 50g] required for 50g of aluminum-containing particles to flow through the orifice of a funnel calibrated to specified dimensions was measured. Here, the flow time of the aluminum-containing particles was measured at least twice. In Table 2, "N.D." means that the powder did not flow even when the orifice was opened, or the flow stopped during measurement, i.e., the case where no measured value was obtained. In Table 2, the numerical value listed in the overall evaluation is the average value of two measured values. n １ and n ２ The values ​​shown are the measured values ​​obtained at each time.

[0076]

[0077]

[0078] The 3D printer-produced objects using the aluminum-containing particles of the Examples had better mechanical strength than the 3D printer-produced objects using the aluminum-containing particles of the Comparative Examples. Furthermore, the 3D printer-produced objects using the aluminum-containing particles of the Examples had fewer internal defects and fewer apparent irregularities on the surface of the objects than the 3D printer-produced objects using the aluminum-containing particles of the Comparative Examples, and thus had superior modeling accuracy.

[0079] This application claims priority based on Japanese Patent Application No. 2024-055794, filed March 29, 2024, the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. D calculated by the following <Particle size measurement> ５０ The particle diameter is 30.0 μm or more and 60.0 μm or less, and D calculated by the following <Particle diameter measurement> ９０ The particle diameter is D １０ The value divided by the particle diameter is 1.5 or more and 3.5 or less, and the apparent density measured in accordance with JIS Z 2504:2020 using a funnel angle of 60° and an orifice with a diameter of 5.0 mm is 1.35 g / cm ３ <Particle size measurement> 3.0 g of aluminum-containing particles were mixed with 40 mL of water and 10 mL of a surfactant having a concentration of 1.3%, and the mixture was dispersed in an ultrasonic bath for 300 seconds to obtain a measurement sample. The volume-based particle size distribution of the aluminum-containing particles was measured using a laser diffraction / scattering particle size measurement device, and D １０ Particle diameter, D ５０ Particle diameter, and D ９０ The particle size values ​​are obtained for each.

2. D calculated by the above <Particle size measurement> １０ The aluminum-containing particles according to claim 1, having a particle diameter of 20.0 μm or more and 40.0 μm or less.

3. D calculated by the above <Particle size measurement> ９０ The aluminum-containing particles according to claim 1 or 2, having a particle diameter of 50.0 μm or more and 100.0 μm or less.

4. The aluminum-containing particles according to any one of claims 1 to 3, having a sphericity of 0.8 or more.

5. Aluminum-containing particles according to any one of claims 1 to 4, having a fluidity of 15.0 sec / 50 g or less in a hole flow test measured in accordance with JIS Z2502:2020.

6. The aluminum-containing particles according to any one of claims 1 to 5, wherein the aluminum-containing particles include at least one selected from the group consisting of pure aluminum particles and aluminum-based alloy particles.

7. The aluminum-containing particles according to claim 6, wherein the aluminum-based alloy particles contain at least one element selected from the group consisting of Cu, Mn, Si, Mg, Zn, and Ni.

8. The aluminum-containing particles according to claim 6 or 7, wherein the aluminum-based alloy particles comprise at least one alloy selected from the group consisting of Al-Si-based alloys, Al-Cu-based alloys, Al-Mn-based alloys, Al-Mg-based alloys, Al-Si-Mg-based alloys, Al-Si-Cu-based alloys, Al-Zn-Mg-based alloys, Al-Si-Mg-Cu-based alloys, Al-Cu-Ni-Mg-based alloys, and Al-Zn-Mg-Cu-based alloys.

9. The aluminum-containing particles according to any one of claims 6 to 8, wherein the aluminum-based alloy particles contain at least one selected from the group consisting of AlSi10Mg and AlSi12.

10. Aluminum-containing particles according to any one of claims 1 to 9, which can be used as a raw material powder for objects formed by 3D printers.

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