Powder metal material for 3D printing made of aluminum alloy, and additive manufacturing method

Abstract

To provide a 3D print-shaping powder metal material made of an aluminum alloy that allows miniaturization of crystal grain and can yield high strength shaped product, and to provide a lamination shaping method using the powder metal material.SOLUTION: Provided are a 3D print-shaping powder metal material that is made of an aluminum alloy containing at least one of Ti, Zr and P, and a lamination shaping method using the powder metal material.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a powder metal material made of an aluminum alloy for 3D printing, and to an additive manufacturing method. [Background technology]

[0002] Aluminum alloys are used in applications where weight reduction is required, such as in vehicles and aircraft. BACKGROUND ART Layered manufacturing methods using aluminum alloy powder are known (see, for example, Patent Documents 1 to 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2021-531398 [Patent Document 2] Japanese Patent Publication No. 2021-152189 [Patent Document 3] Patent No. 6393008 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventionally, grain refinement for increasing the strength of aluminum alloys has been achieved by adding a refiner, as described in Patent Document 1, for example. However, with conventional aluminum alloys, it is difficult to reduce the grain size to 30 μm or less, and the addition of elements such as Cu, Zn, and Ni, which have a high strength-enhancing effect, increases the stress at the grain boundaries, causing cracks and making molding difficult. Therefore, there is a need for further refinement of the grain size. The present invention provides a powder metal material for 3D printing made of an aluminum alloy that allows for the refinement of crystal grains and the production of high-strength objects, and an additive manufacturing method using the powder metal material. [Means for solving the problem]

[0005] The powder metal material of the present invention is a powder metal material for 3D printing made of an aluminum alloy containing at least one of Ti, Zr, and P. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a powder metal material for 3D printing made of an aluminum alloy that allows for the refinement of crystal grains and the production of high-strength objects, and an additive manufacturing method that uses the above powder metal material. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, embodiments of the present invention will be described in detail.

[0008] [Powder metal materials] The powder metal material of the present invention is a powder metal material for 3D printing made of an aluminum alloy containing at least one of Ti, Zr, and P. The powder metal material of the present invention allows for the refinement of crystal grains, and enables the production of high-strength shaped products.

[0009] The aluminum alloy powder metal material of the present invention contains at least one of Ti, Zr, and P. During the solidification process of 3D printing (additive manufacturing using a 3D printer), nuclei highly compatible with the Al matrix, such as Al3Ti, Al3Zr, and AlP, are generated, promoting refinement of the matrix and enabling high strength through grain refinement. Because 3D printing has a faster cooling rate than casting, it is believed that grain refinement is possible. Furthermore, elements (e.g., Cu, Zn, Ni, etc.) can be added to further enhance strength, as they can disperse stress at grain boundaries and prevent cracking.

[0010] The aluminum alloy of the powder metal material of the present invention preferably contains at least one of Ti and Zr, and more preferably contains Ti. The aluminum alloy of the powder metal material of the present invention also preferably contains Ti and Zr.

[0011] In the powder metal material of the present invention, the aluminum alloy preferably further contains at least one of Si, Mg, Zn, Fe, Ni, and Mn, which can improve formability. More preferably, the aluminum alloy contains at least one of Si, Mg, Zn, Fe, and Mn.

[0012] The aluminum alloy of the powder metal material of the present invention is, in mass %, Ti: 0.5 to 3.0% Zr: 3.0% or less, P:3.0% or less, Si: 3.0 to 20.0% Cu: 0.1 to 10.0% Mn: 0.1 to 1.0%, Mg: 0.1 to 3.0%, Ni: 5.0% or less, Cr: 2.0% or less, Zn: 0.05 to 3.0%, Fe: 0.5 to 5.0% It is preferred that the compound contains: Unless otherwise specified, the content of each alloying element is a mass value with the entire aluminum alloy being 100%.

[0013] The powder metal material of the present invention may contain the above-mentioned impurity elements in addition to Al, which is the main constituent element of aluminum alloys, and therefore can be produced from, for example, secondary ingots containing large amounts of impurities such as Fe and Zn, or recycled materials containing large amounts of impurities, which is preferable from the viewpoints of reducing carbon dioxide emissions during production, saving resources, and reducing the environmental load. Furthermore, recycled ingots can be utilized, and the impurity elements in the recycled ingots can be refined, which contributes to increasing strength.

[0014] The aluminum alloy powder metal material of the present invention preferably has the above chemical composition, with the balance being Al and unavoidable impurities. The content of Al in the aluminum alloy of the powder metal material of the present invention is preferably 60 mass % or more, more preferably 70 mass % or more, and even more preferably 80 mass % or more.

[0015] The inevitable impurities are components that may be inevitably mixed in from raw materials or the environment when producing the aluminum alloy of the present invention, and examples thereof include Na, Sb, Sr, Li, etc. The content of the inevitable impurities is usually 0.1 mass% or less.

[0016] The Ti content in the aluminum alloy is preferably 0.5 to 3.0%, more preferably 0.8 to 2.5%, and even more preferably 1.0 to 2.0%.

[0017] The Zr content in the aluminum alloy is preferably 3.0% or less, more preferably 2.5% or less, and even more preferably 2.0% or less. There is no particular lower limit for the Zr content in the aluminum alloy, and it can be 0% by mass or more. The aluminum alloy may not contain Zr. Furthermore, when the aluminum alloy contains Zr, the Zr content may be 0.7 to 2.5%, or 1.0 to 2.0%.

[0018] The P content in the aluminum alloy is preferably 3.0% or less, more preferably 2.0% or less, and even more preferably 1.0% or less. There is no particular lower limit for the P content in the aluminum alloy, and it can be 0% by mass or more. The aluminum alloy does not necessarily contain P. Furthermore, when the aluminum alloy contains P, the P content may be 0.1 to 2.0%.

[0019] The Si content in the aluminum alloy is preferably 3.0 to 20.0%, more preferably 5.0 to 17.0%, further preferably 7.0 to 16.0%, and particularly preferably 8.0 to 15.0%. When the aluminum alloy contains Si, the formability can be improved.

[0020] The Cu content in the aluminum alloy is preferably 0.1 to 10.0%, more preferably 0.5 to 8.0%, further preferably 1.0 to 7.0%, and particularly preferably 3.0 to 5.0%.

[0021] The Mn content in the aluminum alloy is preferably 0.1 to 1.0%, more preferably 0.2 to 0.8%, and even more preferably 0.3 to 0.5%.

[0022] The Mg content in the aluminum alloy is preferably 0.1 to 3.0%, more preferably 0.2 to 2.0%, further preferably 0.3 to 1.0%, and particularly preferably 0.4 to 0.8%.

[0023] The Ni content in the aluminum alloy is preferably 5.0% or less, more preferably 3.0% or less, even more preferably 2.0% or less, and particularly preferably 1.5% or less. There is no particular lower limit for the Ni content in the aluminum alloy, and it can be 0% by mass or more. The aluminum alloy does not necessarily contain Ni.

[0024] The Cr content in the aluminum alloy is preferably 2.0% or less, more preferably 0.5% or less, even more preferably 0.3% or less, and particularly preferably 0.1% or less. There is no particular lower limit for the Cr content in the aluminum alloy, and it can be 0% by mass or more. The aluminum alloy does not necessarily contain Cr.

[0025] The Zn content in the aluminum alloy is preferably 0.05 to 3.0%, more preferably 0.1 to 2.0%, and even more preferably 0.2 to 1.0%.

[0026] The content of Fe in the aluminum alloy is preferably 0.5 to 5.0%, more preferably 0.7 to 4.0%, and even more preferably 1.0 to 3.0%.

[0027] The particle size of the powder metal material of the present invention is not particularly limited, and may be any known particle size suitable for additive manufacturing using a 3D printer (for example, a volume average particle size (D) measured with a laser diffraction particle size distribution analyzer). 50) can be 10 to 200 μm, etc.

[0028] The method for producing the powder metal material of the present invention is not particularly limited, and any known method (for example, gas atomization, plasma atomization, centrifugal atomization, etc.) can be used.

[0029] [Additive manufacturing method] The additive manufacturing method of the present invention uses the above powder metal material to manufacture a part using a 3D printer. The additive manufacturing method of the present invention is a 3D printing method, and since the cooling rate after the powder metal material is melted by irradiation with a laser or electron beam is high, the crystal grains can be made fine. In the additive manufacturing method of the present invention, the cooling rate after the powder metal material is melted is 10 3 °C / sec or more, and 4 It is more preferable that the cooling rate is 10 °C / sec or more. 3 By setting the heating rate at ° C. / sec or more, the crystal grains can be efficiently refined. A known 3D printer can be used. The method of additive manufacturing is not particularly limited, but for example, powder bed fusion, directed energy deposition, etc. are preferred.

[0030] [Sculpture] The average grain size of the crystal grains of the object obtained by additive manufacturing using a 3D printer using the powder metal material of the present invention is preferably 30 μm or less, more preferably 20 μm or less, and even more preferably 10 μm or less.

[0031] The object manufactured by the additive manufacturing method of the present invention has excellent strength and can be used for a variety of purposes, such as automobile parts. [Example]

[0032] EXAMPLES The present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited to these.

[0033] An aluminum alloy powder (average particle size 45 μm) was prepared having the composition shown in Table 1 below. In Table 1, "Bal" represents the "balance."

[0034] The aluminum alloy powders of Examples 1 to 3 were produced by gas atomization. The aluminum alloy powder of Comparative Example 1 was produced using an aluminum alloy that is commercially available as a general material.

[0035] The aluminum alloy powders of the examples and comparative examples in Table 1 were subjected to additive manufacturing using a 3D printer (EOS M290) to produce shaped objects. The 3D printer used had a cooling rate of 10 5 °C / sec.

[0036] <Measurement of crystal grain size> The microstructure of the obtained molded object was observed by EBSD (scanning electron microscope SU6600 manufactured by Hitachi High-Technologies Corporation, symmetry S2 manufactured by Oxford) to determine the average grain size. The average grain size of the crystal grains in Examples 1 to 3 was 5 μm. The average grain size of the crystal grains in Comparative Example 1 was 70 μm. From the above results, it is clear that the aluminum alloy powders of Examples 1 to 3 can have finer crystal grains than the aluminum alloy powder of Comparative Example 1.

[0037] <Measurement of strength> JIS No. 4 test pieces were prepared from the obtained molded objects and subjected to tensile tests at 23°C using a universal testing machine (Shimadzu Autograph). The crosshead speed was 0.1 mm / min. The stress at which the test piece broke was taken as the tensile strength (MPa). The results are shown in the "Strength (MPa)" column in Table 1.

[0038] [Table 1]

[0039] It can be seen from Table 1 that the aluminum alloy powders of Examples 1 to 3 can produce shaped articles with greater strength than the aluminum alloy powder of Comparative Example 1.

[0040] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and modifications, improvements, etc. are possible as appropriate.

[0041] Furthermore, this specification describes at least the following:

[0042] (1) A powder metal material for 3D printing consisting of an aluminum alloy containing at least one of Ti, Zr, and P.

[0043] According to (1), 3D printing enables high strength through grain refinement. In addition, it can disperse stress at grain boundaries and prevent cracks from occurring, making it possible to add elements (e.g., Cu, Zn, Ni, etc.) to further increase strength.

[0044] (2) The powder metal material according to (1), wherein the aluminum alloy further contains at least one of Si, Mg, Zn, Fe, Ni, and Mn.

[0045] According to (2), the molding property can be improved.

[0046] (3) The aluminum alloy is In mass%, Ti: 0.5 to 3.0% Zr: 3.0% or less, P:3.0% or less, Si: 3.0 to 20.0% Cu: 0.1 to 10.0% Mn: 0.1 to 1.0%, Mg: 0.1 to 3.0%, Ni: 5.0% or less, Cr: 2.0% or less, Zn: 0.05 to 3.0%, Fe: 0.5 to 5.0% The powder metal material according to (1) or (2), comprising:

[0047] According to (3), for example, secondary ingots containing a large amount of impurities such as Fe and Zn, or recycled materials containing a large amount of impurities, can be used as raw materials, which contributes to reducing carbon dioxide emissions during manufacturing, saving resources, and reducing the environmental impact. In addition, the use of recycled ingots and the refinement of impurity elements in the recycled ingots can contribute to increasing strength.

[0048] (4) An additive manufacturing method using the powder metal material according to any one of (1) to (3) to manufacture using a 3D printer.

[0049] According to (4), the crystal grains can be refined.

[0050] (5) The cooling rate after the powder metal material is melted is 10 3 The layered manufacturing method according to (4), wherein the temperature is ℃ / sec or higher.

[0051] According to (5), the crystal grains can be refined efficiently.

Claims

1. A powder metal material for 3D printing made of an aluminum alloy, The aluminum alloy is In mass%, Ti: 0.5-3.0%, Zr: 3.0% or less, Si: 3.0-20.0%, Cu: 0.1-10.0%, Mn: 0.1-1.0%, Mg: 0.1-3.0%, Zn: 3.0% or less, Fe: 5.0% or less and the remainder consisting of Al and unavoidable impurities.

2. An additive manufacturing method, comprising: forming a product using the powder metal material according to claim 1 with a 3D printer.

3. The cooling rate after the powder metal material is melted is 10 ３ The layered manufacturing method according to claim 2 , wherein the heating rate is ° C. / sec or more.

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