Manufacturing method for heat-resistant alloys

Abstract

The present invention aims to provide a new method for manufacturing heat-resistant alloys. [Solution] By manufacturing an Al-Fe-Cu-Mn quaternary alloy using laser powder bed fusion (LPBF method, powder bed fusion method, or LPBF additive manufacturing process), one of the metal additive manufacturing methods, it is possible to create a high-strength and high-performance alloy with a non-equilibrium structure or metastable phase. In the LPBF method, the cooling rate of the molten metal is 10 5 K·s -1 ~10 7 K·s -1 That is the case.

Description

[Technical Field]

[0001] This invention relates to a method for manufacturing heat-resistant alloys. [Background technology]

[0002] Non-patent document 1 discloses the evaluation of the heat resistance of an Al-Fe-Cu-Mn quaternary alloy.

[0003] Non-patent document 2 discloses the production of an Al-Fe-Mn ternary alloy using the laser powder bed fusion (LPBF) method, and the evaluation of the heat resistance of the Al-Fe-Mn ternary alloy. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Materials Transactions, Vol. 64, No. 2 (2023) pp. 492 to 499 Effects of Mn and Cu Additions on Solidification Microstructure and High-Temperature Strength of Cast Al-Fe Binary Alloy [Non-Patent Document 2] Additive Manufacturing 68 (2023) Design of Al-Fe-Mn alloy for both high-temperature strength and sufficient processability of laser powder bed fusion [Overview of the project] [Problems that the invention aims to solve]

[0005] The present invention aims to provide a new method for manufacturing heat-resistant alloys. [Means for solving the problem]

[0006] The present invention can create high-strength and high-functional alloys with non-equilibrium structures or metastable phases by manufacturing a quaternary alloy of Al-Fe-Cu-Mn according to the laser powder bed fusion method (Laser Powder Bed Fusion, LPBF method, powder bed fusion method, or LPBF additive manufacturing process), which is one of the metal additive manufacturing methods.

[0007] The present invention includes the following method for manufacturing a quaternary alloy of Al-Fe-Cu-Mn.

[0008] Item 1. A method for manufacturing a laminated body of a quaternary alloy of Al-Fe-Cu-Mn using the laser powder bed fusion (LPBF) method.

[0009] Item 2. In the LPBF method, the cooling rate of the molten metal is 10 5 K·s -1 ~10 7 K·s -1 The method for manufacturing the laminated body according to Item 1 above.

[0010] The present invention can create high-strength and high-functional alloys with non-equilibrium structures or metastable phases by manufacturing a quaternary alloy of Al-Fe-Cu-Mn according to the LPBF method. The quaternary alloy of Al-Fe-Cu-Mn of the present invention can obtain a high tensile strength of about 450 MPa at room temperature (about 20°C).

[0011] The quaternary alloy of Al-Fe-Cu-Mn of the present invention can be applied to various lightweight and heat-resistant members, such as rotating body parts of automotive engine compressors.

Effects of the Invention

[0012] The present invention can newly provide a method for manufacturing a heat-resistant alloy.

Brief Description of the Drawings

[0013] [Figure 1] Figure 1 shows a scanning electron microscope image of the Al-2.5Fe-2Cu-2Mn (mass%) alloy powder used in the LPBF shaping of the present invention. [Figure 2] Figure 2 shows the appearance of an Al-2.5Fe-2Cu-2Mn (mass%) alloy sample shaped by LPBF of the present invention. [Figure 3] Figure 3 shows the change in relative density of an Al-2.5Fe-2Cu-2Mn (mass%) alloy sample shaped by LPBF of the present invention under conditions of different laser powers (P) and laser scanning speeds (v). [Figure 4] Figure 4 shows an optical microscope image showing the microstructure of an Al-2.5Fe-2Cu-2Mn (mass%) alloy shaped by LPBF of the present invention. [Figure 5] Figure 5 shows a scanning transmission electron microscope (STEM) image of an Al-2.5Fe-2Cu-2Mn (mass%) alloy shaped by LPBF of the present invention and elemental distribution diagrams of Fe, Mn, and Cu. It can be seen that Mn and Cu are concentrated in the nano-sized Al6Fe phase. [Figure 6] Figure 6 shows the nominal stress-strain curves at room temperature of Al-2.5Fe, Al-2.5Fe-2Mn, and Al-2.5Fe-2Cu-2Mn (mass%) alloys of the present invention shaped by LPBF: (a) shows the tensile direction perpendicular to the shaping direction. It can be seen that the room temperature strength and ductility of the alloy are improved by the addition of Cu and Mn. [Figure 7] Figure 7 shows the nominal stress-strain curves at room temperature of Al-2.5Fe, Al-2.5Fe-2Mn, and Al-2.5Fe-2Cu-2Mn (mass%) alloys of the present invention shaped by LPBF: (b) shows the tensile direction parallel to the shaping direction. It can be seen that the room temperature strength and ductility of the alloy are improved by the addition of Cu and Mn. [Figure 8]Figure 8 shows the change in maximum tensile strength with temperature for Al-2.5Fe, Al-2.5Fe-2Mn, and the Al-2.5Fe-2Cu-2Mn (mass%) alloy of the present invention fabricated by LPBF. It can be seen that the alloy has high strength at room temperature and decreases at high temperatures. The Al-Fe-Cu-Mn quaternary alloy produced by the LPBF method of the present invention is a high-strength, high-performance alloy with a non-equilibrium structure or metastable phase, and in particular, it can be seen that high tensile strength can be obtained at room temperature (approximately 20°C) and approximately 450 MPa. [Figure 9] Figure 9 shows the change in yield strength (0.2% proof stress) with temperature between a cast Al-2.5Fe-2Cu-2Mn (mass%) alloy and an LPBF molded body of the present invention. It can be seen that the Al-Fe-Cu-Mn quaternary alloy (L-PBF molded body) produced by the LPBF method of the present invention exhibits more than twice the yield strength compared to conventional cast materials. [Modes for carrying out the invention]

[0014] The present invention will be described in detail below. The embodiments illustrating the present invention are intended to provide a better understanding of the spirit of the invention and do not limit the scope of the invention unless otherwise specified.

[0015] In this specification, "contains" and "include" are concepts that encompass all of the following: "comprise," "consist essentially of," and "consist of."

[0016] In this specification, when a numerical range is indicated as "A to B", it means "greater than or equal to A and less than or equal to B".

[0017] In this specification, the terms parts, percentages, etc. are generally used to represent parts by mass, parts by weight, mass%, and weight% (mass%).

[0018] [1] Method for manufacturing additive bodies Laser powder bed fusion (LPBF) method (Laser Powder Bed Fusion, or LPBF additive manufacturing process) This invention relates to a method for manufacturing additively fabricated structures of an Al-Fe-Cu-Mn quaternary alloy using laser powder bed fusion (LPBF) technology.

[0019] In the method for manufacturing additively fabricated bodies of the present invention, preferably, the LPBF method is characterized by a cooling rate of 10°C of the molten metal. 5 K·s -1 ~10 7 K·s -1 (Ultra-rapid solidification).

[0020] This invention enables the creation of high-strength and high-performance alloys with non-equilibrium structures or metastable phases by producing an Al-Fe-Cu-Mn quaternary alloy using the LPBF method, which is a type of metal additive manufacturing method.

[0021] The Al-Fe-Cu-Mn quaternary alloy of the present invention exhibits high tensile strength at approximately 450 MPa at room temperature (approximately 20°C).

[0022] The Al-Fe-Cu-Mn quaternary alloy of the present invention can be applied to various lightweight and heat-resistant components, such as rotational components for automobile engine compressors.

[0023] LPBF 3D printing The present invention provides a method for manufacturing an additively fabricated body, which includes the step of fabricating an additively fabricated body of an Al-Fe-Cu-Mn quaternary alloy using a laser powder bed fusion (LPBF) method.

[0024] LPBF (Laser Powder Bed Fusion) is a type of metal 3D printing method. In the LPBF method, a laser is shone onto a portion of a thin layer of powder laid on the bed, solidifying the irradiated area. This process is then repeated layer by layer to create complex three-dimensional structures. The LPBF method is characterized by rapid solidification.

[0025] LPBF (Laser-Based Fabrication) is the most commonly used metal additive manufacturing technology. It is a method of creating three-dimensional structures layer by layer by repeatedly laying down metal powder and melting and solidifying the metal powder using laser irradiation.

[0026] (Alloy powder) This invention enables the creation of high-strength and high-performance Al-Fe-Cu-Mn quaternary alloys with non-equilibrium structures or metastable phases by producing Al-Fe-Cu-Mn quaternary alloys using the LPBF method. The Al-Fe-Cu-Mn quaternary alloy of this invention exhibits high tensile strength at room temperature (approximately 20°C) and approximately 450 MPa.

[0027] In LPBF fabrication, it is possible to create high-strength and high-performance Al-Fe-Cu-Mn quaternary alloys with non-equilibrium structures or metastable phases. Furthermore, since Al-Fe-Cu-Mn quaternary alloys can achieve high tensile strength at room temperature (approximately 20°C) and approximately 450 MPa, Al-2.5Fe-2Cu-2Mn (mass%) alloy powder is preferably used.

[0028] In the Al-Fe-Cu-Mn quaternary alloy powder, aluminum (Al) is the main component (Bal.).

[0029] In the alloy powder of the Al-Fe-Cu-Mn quaternary alloy, thermodynamic calculations have shown that in LPBF fabrication, the volume fraction of the primary compound phase, which causes cracking during laser irradiation, should be 10% or less. In the manufactured LPBF fabricated body, the volume fraction of the Al6Fe phase, which contributes to strength, should be adjusted to 6% to 12%. Therefore, the composition ratio of iron element (Fe) is preferably 2.5 mass% ± 1.5 mass%, more preferably 2.5 mass% ± 0.5 mass%, and even more preferably about 2.5 mass%.

[0030] In the alloy powder of the Al-Fe-Cu-Mn quaternary alloy, based on the calculations using thermodynamics, in LPBF forming, the volume fraction of the primary crystal compound phase that causes cracking during laser irradiation is set to 10% or less. In the manufactured LPBF formed body, from the point of adjusting the volume fraction of the Al6Fe phase that contributes to strength to 6% - 12%, the composition ratio of the copper element (Cu) is preferably 2 mass% ± 1 mass%, more preferably 2 mass% ± 0.5 mass%, and still more preferably includes about 2 mass%.

[0031] In the alloy powder of the Al-Fe-Cu-Mn quaternary alloy, based on the calculations using thermodynamics, in LPBF forming, the volume fraction of the primary crystal compound phase that causes cracking during laser irradiation is set to 10% or less. In the manufactured LPBF formed body, from the point of adjusting the volume fraction of the Al6Fe phase that contributes to strength to 6% - 12%, the composition ratio of the manganese element (Mn) is preferably 2 mass% ± 1 mass%, more preferably 2 mass% ± 0.5 mass%, and still more preferably includes about 2 mass%.

[0032] Table 1 shows the preferred chemical compositions of the raw material powders for manufacturing the Al-Fe-Cu-Mn quaternary alloy.

[0033]

Table 1

[0034] When LPBF forming is performed using the alloy powder of the above Al-Fe-Cu-Mn quaternary alloy, preferably, a quaternary alloy of Al-2.5Fe-2Cu-2Mn (mass%) can be obtained.

[0035] (Cooling rate of molten metal) In LPBF forming, a non-equilibrium structure or a high-strength and high-functional Al-Fe-Cu-Mn quaternary alloy of metastable phases can be created. Also, the Al-Fe-Cu-Mn quaternary alloy has a high tensile strength of about 450 MPa at room temperature (about 20°C). Therefore, preferably, the cooling rate of the molten metal is 10 5 K·s -1 ~107 K·s -1 That is the case.

[0036] In the L-PBF method, the cooling rate of the molten metal is preferably 10 3 K·s -1 That is all, more preferably 10 5 K·s -1 ~10 7 K·s -1 That is the case.

[0037] Table 2 shows the preferred LPBF process conditions.

[0038] [Table 2]

[0039] In the present invention's method for manufacturing an Al-Fe-Cu-Mn quaternary alloy additive body, the LPBF method is used, which allows the cooling rate of the molten metal to be 10 5 K·s -1 ~10 7 K·s -1 This method allows for extremely rapid cooling, enabling the creation of a fine structure. By using the LPBF method, a scaly structure called a molten pool structure is formed (Figure 4). Metal additive manufacturing offers a high degree of freedom in the shape of the fabricated sample. Metal additive manufacturing allows for the creation of three-dimensional structures tailored to specific purposes.

[0040] [2] Additive fabricated body The Al-Fe-Cu-Mn quaternary alloy produced by the LPBF method of the present invention exhibits high strength and high functionality in its non-equilibrium structure or metastable phase. The Al-Fe-Cu-Mn quaternary alloy of the present invention shows high tensile strength at room temperature (approximately 20°C) and approximately 450 MPa.

[0041] The preferred chemical composition of an Al-Fe-Cu-Mn quaternary alloy LPBF molded body can be prepared by adjusting the chemical composition of the Al-Fe-Cu-Mn quaternary alloy powder used for LPBF molding.

[0042] In LPBF (Low-Purpose Blue-Blocked Foam) fabricated bodies made of Al-Fe-Cu-Mn quaternary alloys, aluminum (Al) is the main component (Bal.).

[0043] In LPBF molded bodies of Al-Fe-Cu-Mn quaternary alloys, thermodynamic calculations determine that the Al6Fe phase, which contributes to strength, should be adjusted to a volume fraction of 6% to 12%. Therefore, the composition ratio of iron (Fe) is preferably 2.5 mass% ± 1.5 mass%, more preferably 2.5 mass% ± 0.5 mass%, and even more preferably about 2.5 mass%.

[0044] In LPBF molded bodies of Al-Fe-Cu-Mn quaternary alloys, thermodynamic calculations determine that the Al6Fe phase, which contributes to strength, is adjusted to a volume fraction of 6% to 12%. Therefore, the composition ratio of copper (Cu) is preferably 2 mass% ± 1 mass%, more preferably 2 mass% ± 0.5 mass%, and even more preferably about 2 mass%.

[0045] In LPBF molded bodies of Al-Fe-Cu-Mn quaternary alloys, thermodynamic calculations determine that the Al6Fe phase, which contributes to strength, is adjusted to a volume fraction of 6% to 12%. Therefore, the composition ratio of manganese element (Mn) is preferably 2 mass% ± 1 mass%, more preferably 2 mass% ± 0.5 mass%, and even more preferably about 2 mass%.

[0046] Table 3 shows the preferred chemical compositions of LPBF molded bodies made of Al-Fe-Cu-Mn quaternary alloys.

[0047] [Table 3]

[0048] After LPBF fabrication, it is preferable to obtain a quaternary alloy of Al-2.5Fe-2Cu-2Mn (mass%).

[0049] The Al-Fe-Cu-Mn quaternary alloy of the present invention can be applied to various lightweight and heat-resistant components, such as rotating parts for automobile engine compressors. [Examples]

[0050] The embodiments of the present invention will be described in more detail below based on the examples. However, the present invention is not limited to the scope of the embodiments.

[0051] [1] Manufacturing of additive bodies (Laser powder bed fusion (LPBF) method) A quaternary alloy of Al-Fe-Cu-Mn was fabricated using the LPBF method.

[0052] Table 4 shows the chemical composition of the raw material powders as measured by ICP emission spectrometry.

[0053] [Table 4]

[0054] Figure 1 shows a scanning electron microscope image of the Al-2.5Fe-2Cu-2Mn (mass%) alloy powder used in LPBF fabrication.

[0055] In the LPBF method, the laser power (P) is set to 102W-204W and the scanning speed (v) to 0.6m·s. -1 ~1.4 m·s -1 The molded objects were created under 25 conditions with a hatch distance (S) of 30 μm.

[0056] Table 5 shows the LPBF process conditions.

[0057] [Table 5]

[0058] The LPBF method has a cooling rate of 10 5 K·s -1 ~10 7 K·s-1 One of its features is that it can produce very fine tissue very quickly.

[0059] [2] Evaluation of additively manufactured bodies

[0060] Figure 2 shows the appearance of an Al-2.5Fe-2Cu-2Mn (mass%) alloy sample fabricated using LPBF.

[0061] Table 6 shows the chemical composition of the LPBF molded body as measured by ICP emission spectrometry.

[0062] [Table 6]

[0063] Subsequently, the relative density of the molded object was measured using the Archimedes method.

[0064] Figure 3 shows the change in relative density of Al-2.5Fe-2Cu-2Mn (mass%) alloy samples fabricated using LPBF under different laser power (P) and laser scanning speed (v) conditions.

[0065] Figure 4 shows an optical microscope image of the microstructure of an Al-2.5Fe-2Cu-2Mn (mass%) alloy fabricated using LPBF.

[0066] Figure 5 shows scanning transmission electron microscope (STEM) images and elemental distribution maps of Fe, Mn, and Cu of an Al-2.5Fe-2Cu-2Mn (mass%) alloy fabricated using LPBF. It can be seen that Mn and Cu are concentrated in the nanoscale Al6Fe phase.

[0067] Figure 6 shows the nominal stress-strain curves at room temperature for the alloys Al-2.5Fe (reference example), Al-2.5Fe-2Mn (reference example), and Al-2.5Fe-2Cu-2Mn (mass%) (invention) fabricated using LPBF: (a) the tensile direction perpendicular to the fabrication direction. Figure 7 shows the nominal stress-strain curves at room temperature for the alloys: (b) the tensile direction parallel to the fabrication direction.

[0068] The Al-2.5Fe-2Cu-2Mn (mass%) alloy of the present invention shows improved room-temperature strength and ductility through the addition of Cu and Mn.

[0069] Figure 8 shows the change in maximum tensile strength with temperature for Al-2.5Fe (reference example), Al-2.5Fe-2Mn (reference example), and Al-2.5Fe-2Cu-2Mn (mass%) (invention) alloys fabricated using LPBF. It can be seen that the alloys have high strength at room temperature and decrease at high temperatures.

[0070] The Al-Fe-Cu-Mn quaternary alloy produced by the LPBF method of the present invention is a high-strength, high-performance alloy with a non-equilibrium structure or metastable phase, and in particular, it is found to achieve high tensile strength at room temperature (approximately 20°C) and approximately 450 MPa.

[0071] Figure 9 shows the change in yield strength (0.2% proof stress) with temperature for Al-2.5Fe-2Cu-2Mn(mass%) alloy, comparing a cast material (reference example) with an LPBF molded body (invention).

[0072] It has been found that the Al-Fe-Cu-Mn quaternary alloy (LPBF molded body) produced by the LPBF method of the present invention exhibits more than twice the yield strength compared to conventional cast materials.

[0073] [3] Industrial applicability of additive manufacturing This invention enables the creation of high-strength and high-performance alloys with non-equilibrium structures or metastable phases by producing an Al-Fe-Cu-Mn quaternary alloy using the LPBF method, which is a type of metal additive manufacturing method.

[0074] The Al-Fe-Cu-Mn quaternary alloy of the present invention exhibits high tensile strength of approximately 450 MPa at room temperature (approximately 20°C).

[0075] The Al-Fe-Cu-Mn quaternary alloy of the present invention can be applied to various lightweight and heat-resistant components, such as rotating parts for automobile engine compressors.

Claims

1. A method for manufacturing additively fabricated structures of an Al-Fe-Cu-Mn quaternary alloy using laser powder bed fusion (LPBF).

2. The aforementioned LPBF method has a cooling rate of 10 5 K・s -1 ~10 7 K・s -1 The method for manufacturing an additively manufactured body according to claim 1.

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