A refractory high-entropy alloy particle-reinforced aluminum matrix composite material and its layered scanning additive manufacturing method

Abstract

This invention discloses an aluminum matrix composite material reinforced with refractory high-entropy alloy particles and its layered scanning additive manufacturing method. In this invention, a refractory high-entropy alloy is used as the reinforcing phase. During the additive manufacturing process, the laser scanning speed is progressively controlled, increasing with the number of printing layers. This alters the laser's heat input, influencing the fluid flow and thermal gradient within the molten pool. This allows the aluminum matrix to fully melt while the refractory high-entropy alloy particles are retained relatively intact, achieving a good metallurgical bond between the reinforcing particles and the aluminum matrix. Furthermore, the microstructure becomes more homogeneous, and the grain growth pattern of the aluminum matrix changes from columnar crystal growth to equiaxed crystal growth parallel to the construction direction, significantly reducing the anisotropy of the composite material. The refractory high-entropy alloy particle-reinforced aluminum matrix composite material prepared by this invention exhibits excellent mechanical properties.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing technology of metal matrix composites, specifically relating to an aluminum matrix composite material reinforced with refractory high-entropy alloy particles and its layered scanning additive manufacturing method. Background Technology

[0002] With the rapid development of technologies in aerospace, automotive, and rail transportation, higher requirements are being placed on the strength and other properties of aluminum alloys. Aluminum-based composites use aluminum alloys as the matrix, with reinforcements added to improve the properties of the matrix material. Commonly used reinforcing phases are mainly ceramic materials. Although ceramic reinforcements have high strength and hardness, the poor wettability of ceramic particles at the aluminum matrix interface results in low bonding strength, easily causing plasticity deviations in the composite material and limiting the application of ceramic particle-reinforced aluminum-based composites. Therefore, how to select a more suitable reinforcing particle to further explore the mechanical property potential of aluminum-based composites is an urgent problem to be solved in this field.

[0003] Refractory high-entropy alloys are mainly composed of elements such as W, Ta, Mo, Nb, V, Ti, and Hf. These high-entropy alloys possess excellent characteristics such as high melting points and high strength. Studies have found that high-entropy alloys and aluminum matrices have similar coefficients of thermal expansion, and the natural interfacial bonding characteristics between metals result in good interfacial wettability between the high-entropy alloy and the aluminum matrix. Furthermore, some elements, such as Ti, Ta, and Nb, can form grain refiners like Al3Ti with the aluminum matrix, thereby refining the grain size of the aluminum matrix. While there are reports on high-entropy alloys as reinforcing phases, these mainly focus on traditional FeCoCrNi and AlCoCrFeNi series high-entropy alloys. There are no reports on the use of refractory high-entropy alloys as reinforcing phases in the preparation of aluminum matrix composites.

[0004] Additive manufacturing technology is currently one of the important preparation technologies for aluminum-based composite materials. Commonly used techniques include selective laser melting (SLM). Due to the high reflectivity of aluminum alloys to infrared lasers, the presence of reinforcing phases can effectively improve the laser absorption rate, and this technology can form parts with complex shapes. During laser printing, the unique thermal history and high temperature gradient inside the molten pool can easily lead to significant thermal stress in the parts during solidification. There are reports of using laser remelting technology to control the thermal history and temperature gradient inside the molten pool, which can reduce internal defects and residual stress and improve the part forming quality. However, this also significantly increases the material preparation time and cost. Currently, there are no reports of using layer-by-layer scanning to improve the microstructure and properties of composite materials while ensuring printing efficiency. Therefore, the rational design of relevant process parameters is a problem that urgently needs to be solved by those skilled in the art in the preparation of aluminum-based composite materials.

[0005] In conclusion, in order to further improve the performance of aluminum alloys and expand their application range, the development of new aluminum-based composite material systems and their preparation methods is of great significance to aerospace, automotive, rail transportation and other fields. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide an aluminum-based composite material reinforced with refractory high-entropy alloy particles and its layered scanning additive manufacturing method, thereby solving the problems of premature failure of aluminum-based composite materials prepared by additive manufacturing due to the addition of ceramic reinforcing particles, poor interfacial wettability between the reinforcing phase and the aluminum matrix, and residual internal stress in the composite material caused by process parameters in the prior art.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A refractory high-entropy alloy particle-reinforced aluminum matrix composite material and its layered scanning additive manufacturing method are disclosed. The material composition is characterized by the matrix being various aluminum alloys, including cast aluminum alloys such as Al-Si, Al-Cu, Al-Mg, and Al-Zn alloys; and some wrought aluminum alloys such as I-series, II-series, IV-series, V-series, and VI-series aluminum alloys. The reinforcing phase is a refractory high-entropy alloy, including TiNbZrTa, WTaMoNb, HfNbZrTa, TiTaNbV, and TiNbHfZr alloys.

[0009] Furthermore, the mass fraction of the refractory high-entropy alloy powder is between 1% and 10%, and the mass fraction of the aluminum alloy powder is between 90% and 99%, and the sum of the two is equal to 100%. The refractory high-entropy alloy powder is spherical with a particle size between 1 and 53 μm, and the aluminum alloy powder is spherical with a particle size between 1 and 90 μm.

[0010] The layered scanning additive manufacturing method for refractory high-entropy alloy particle-reinforced aluminum matrix composite materials of the present invention specifically includes the following steps:

[0011] (1) Preparation of composite powder: Weigh out a certain mass fraction of refractory high entropy alloy powder and aluminum alloy powder, mix them evenly with a powder mixing device, pass a protective gas through the mixture, and dry it after passing it through a standard sieve to obtain composite powder of refractory high entropy alloy particles reinforced with aluminum alloy.

[0012] (2) Layered scanning additive manufacturing of aluminum-based composite materials: A 3D model is created and sliced ​​using 3D software. The composite powder is spread evenly on the substrate of the SLM (Selective Laser Melting) metal 3D printer's forming chamber. The substrate is preheated in a protective gas atmosphere. The laser power, scanning spacing, etc., are adjusted, and the scanning speed is controlled in stages: every 5 layers constitutes one cycle. The scanning speed for the first layer is A mm / s, the second layer is A+n×100mm / s, the third layer is A+2n×100mm / s, the fourth layer is A+3n×100mm / s, and the fifth layer is A+4n×100mm / s. The scanning speed for the first layer in the next cycle remains A mm / s, and so on, allowing the laser to periodically scan layer by layer on the powder bed to print the aluminum-based composite material. A schematic diagram of layered scanning additive manufacturing is shown below. Figure 1 As shown.

[0013] Preferably, the powder mixing equipment mentioned in step (1) is a ball mill or a V-type powder mixer, etc., wherein the ball milling time is 4-10 hours, the rotation speed is 120-200 rpm, the grinding balls are ZrO2 grinding balls or stainless steel grinding balls, the size of the grinding balls is 1-5 mm, the ball-to-material ratio is 1:1-5:1, and the protective gas is nitrogen or argon, etc.; the powder mixing time of the V-type powder mixer is 4-8 hours. After the powder is mixed evenly, it is sieved and dried in a vacuum environment at 70-100℃ for 3-6 hours.

[0014] Preferably, in step (2), the substrate used in the printing process is a 1-series, 2-series, 4-series, 5-series, or 6-series aluminum alloy, and the substrate is preheated in a nitrogen or argon atmosphere at a temperature of 100°C to 200°C.

[0015] Preferably, in step (2), the laser power is 300–380W, the scanning spacing is 100–160μm, and the powder layer thickness is 20–40μm. The graded control of the scanning speed is as follows: n = (1, 2, 3) and n remains the same throughout the entire printing process; the scanning speeds A mm / s and A+4n×100mm / s are both in the range of 900–2100mm / s.

[0016] A refractory high-entropy alloy particle-reinforced aluminum-based composite material was prepared by the above-mentioned selective laser melting process.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0018] This invention discloses a method of incorporating a refractory high-entropy alloy as a reinforcing phase into an aluminum-based composite material. On one hand, the refractory high-entropy alloy powder is dispersed within the aluminum alloy powder, improving laser absorption and forming quality during printing. On the other hand, due to the significant difference in melting points between the refractory high-entropy alloy and the aluminum matrix, and the naturally good wettability of the high-entropy alloy and the aluminum matrix, most of the refractory high-entropy alloy particles can be completely retained within the matrix, resulting in excellent metallurgical bonding at the interface. During printing, layered scanning is achieved by controlling the scanning speed in stages, effectively homogenizing the thermal gradient within the molten pool and preventing defects such as cracks and voids during forming. Furthermore, because the refractory high-entropy alloy contains elements that refine the aluminum alloy grains, it alters the grain growth pattern, transforming columnar grain growth into equiaxed grain growth parallel to the construction direction, significantly improving the mechanical properties of the aluminum-based composite material. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of layered scanning additive manufacturing.

[0020] Figure 2 The image shows the metallographic structure of the composite material obtained in Example 1, perpendicular to the construction direction.

[0021] Figure 3 The image shows the metallographic structure of the composite material obtained in Example 1, parallel to the construction direction.

[0022] Figure 4 This is a metallographic diagram of AlSi10Mg obtained by comparative printing, parallel to the construction direction.

[0023] Figure 5 The room temperature tensile curves of the composite materials obtained from Example 1 and the comparative example are shown. Detailed Implementation

[0024] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings. The embodiments listed below are only some embodiments of the present invention, and it should be understood that the scope of protection of the present invention is not limited thereto.

[0025] Example 1

[0026] Step (1) Preparation of composite powder: The selected refractory high entropy alloy powder is TiNbZrTa with a particle size of 1-25 μm, and the aluminum alloy powder is AlSi10Mg with a particle size of 15-53 μm. Weigh a certain mass ratio of refractory high entropy alloy powder and aluminum alloy powder, wherein the mass fraction of TiNbZrTa powder is 2% and the remainder is AlSi10Mg powder. The powder is mixed by ball milling. The stainless steel grinding balls used are 1 mm, 3 mm and 5 mm in size. Weigh the stainless steel balls at a mass ratio of 15:5:3 and the ball-to-material ratio is 2:1. Add the powder and grinding balls to the ball mill jar and mix for 4 h. Argon gas is introduced as a protective gas and the rotation speed is 100 rpm. After mixing, the powder is sieved and dried in a vacuum drying oven at 70℃ for 4 h to obtain the composite powder of TiNbZrTa and AlSi10Mg.

[0027] Step (2) Layered scanning additive manufacturing of aluminum-based composite materials: A 3D model is created and sliced ​​using 3D software. The composite powder from step (1) is spread evenly on the substrate of the SLM metal 3D printer's forming chamber. In this embodiment, 5083 aluminum alloy plate is used. The temperature is preheated to 150°C, and the protective atmosphere inside the printing chamber is argon. The printing process parameters are set as follows: laser power is 350W, scanning distance is 150μm, powder layer thickness is 30μm, and the scanning speed is controlled in stages: every 5 layers constitutes one cycle, the scanning speed A of the first layer is 1000mm / s, and in this embodiment, n=2. The scanning speeds of the next four layers are 1200mm / s, 1400mm / s, 1600mm / s, and 1800mm / s, respectively. This cycle is repeated to print the aluminum-based composite material.

[0028] The prepared aluminum-based composite material was characterized by its microstructure, hardness, and room temperature tensile mechanical properties that meet national standards. Figure 2 The metallographic structure of the composite material printed in Example 1, perpendicular to the construction direction, shows that spherical refractory high-entropy alloy particles are distributed inside the aluminum matrix as reinforcing phases. Figure 3 The image shows the metallographic structure parallel to the construction direction. The refractory high-entropy alloy particles are well bonded to the aluminum matrix interface. Comparing this with the metallographic structure of AlSi10Mg printed in the comparative example, which is parallel to the construction direction, it is evident that the matrix structure consists of columnar crystal growth. Figure 4 ) transforms into equiaxed crystal growth ( Figure 3 Comparing the tensile properties of Example 1 and the comparative example, it was found that the yield strength and tensile strength of the aluminum matrix composite were significantly improved, increasing from 208.55 MPa and 382.07 MPa to 311.73 MPa and 483.55 MPa, respectively, while the elongation remained at 4.67%. Figure 5 As shown, the hardness also increased from 126.4 HV to 161.9 HV.

[0029] Example 2

[0030] Step (1) Preparation of composite powder: The selected refractory high entropy alloy powder is TiNbZrTa with a particle size of 15-53 μm, and the aluminum alloy powder is AlSi10Mg with a particle size of 15-53 μm. Weigh a certain mass ratio of refractory high entropy alloy powder and aluminum alloy powder, wherein the mass fraction of TiNbZrTa powder is 3% and the remainder is AlSi10Mg powder. The powder is mixed by ball milling. The stainless steel grinding balls used are 1 mm, 3 mm and 5 mm in size. Weigh the stainless steel balls at a mass ratio of 15:5:3 and the ball-to-material ratio is 1:1. Add the powder and grinding balls to the ball mill jar and mix for 6 h. Argon gas is introduced as a protective gas and the rotation speed is 120 rpm. After mixing, the powder is sieved and dried in a vacuum drying oven at 70℃ for 4 h to obtain the composite powder of TiNbZrTa and AlSi10Mg.

[0031] Step (2) Layered scanning additive manufacturing of aluminum-based composite materials: A 3D model is created and sliced ​​using 3D software. The composite powder from step (1) is spread evenly on the substrate of the SLM metal 3D printer's forming chamber. In this embodiment, 5083 aluminum alloy plate is used. The temperature is preheated to 150°C, and the protective atmosphere inside the printing chamber is argon. The printing process parameters are set as follows: laser power is 350W, scanning distance is 150μm, powder layer thickness is 30μm, and the scanning speed is controlled in stages: every 5 layers constitutes one cycle, the scanning speed A of the first layer is 1000mm / s, and in this embodiment, n=2. The scanning speeds of the next four layers are 1200mm / s, 1400mm / s, 1600mm / s, and 1800mm / s, respectively. This cycle is repeated to print the aluminum-based composite material.

[0032] Microstructure characterization, hardness testing, and room temperature tensile mechanical property testing meeting national standards were performed on the prepared aluminum-based composite material. Significant improvements were observed: the yield strength and tensile strength of the aluminum-based composite material were greatly increased, reaching 326.49 MPa and 497.68 MPa respectively, while the elongation remained at 4.53%, and the hardness also increased to 172.68 HV. The metallographic structure of the aluminum-based composite material (and...) was observed... Figure 2 , 3 (Similar findings) More spherical particles were found to be distributed within the matrix, and the interface bonding was good.

[0033] Example 3

[0034] Step (1) Preparation of composite powder: The selected refractory high entropy alloy powder is WTaMoNb with a particle size of 1-25 μm, and the aluminum alloy powder is AlSi10Mg with a particle size of 15-53 μm. Weigh a certain mass ratio of refractory high entropy alloy powder and aluminum alloy powder, wherein the mass fraction of WTaMoNb powder is 1% and the remainder is AlSi10Mg powder. The powder is mixed by ball milling. The stainless steel grinding balls used are 1 mm, 3 mm and 5 mm in size. Weigh the stainless steel balls at a mass ratio of 15:5:3 and the ball-to-material ratio is 1:1. Add the powder and grinding balls to the ball mill jar and mix for 8 h. Argon gas is introduced as a protective gas and the rotation speed is 140 rpm. After mixing, the powder is sieved and dried in a vacuum drying oven at 70 °C for 4 h to obtain the composite powder of WTaMoNb and AlSi10Mg.

[0035] Step (2) Layered scanning additive manufacturing of aluminum-based composite materials: A 3D model is created and sliced ​​using 3D software. The composite powder from step (1) is spread evenly on the substrate of the SLM metal 3D printer's forming chamber. In this embodiment, 5083 aluminum alloy plate is used. The temperature is preheated to 200℃, and the protective atmosphere inside the printing chamber is argon. The printing process parameters are set as follows: laser power is 300W, scanning distance is 140μm, powder layer thickness is 30μm, and the scanning speed is controlled in stages: every 5 layers constitutes one cycle, the scanning speed A of the first layer is 900mm / s, and in this embodiment, n=3. The scanning speeds of the next four layers are 1200mm / s, 1500mm / s, 1800mm / s, and 2100mm / s, respectively. This cycle is repeated to print the aluminum-based composite material.

[0036] The prepared aluminum-based composite material was characterized by its microstructure, hardness, and room temperature tensile mechanical properties (meeting national standards). Significant improvements were observed, including a substantial increase in yield strength and tensile strength to 316.5 MPa and 486.9 MPa, respectively, while maintaining an elongation of 4.6%. The hardness also increased to 169.5 HV. The metallographic structure of the aluminum-based composite material was observed (and...). Figure 2 , 3 (Similarly) it was found that small spherical particles were distributed in the matrix, and there were no obvious defects in the structure. The structure parallel to the construction direction was fine equiaxed crystals.

[0037] Example 4

[0038] Step (1) Preparation of composite powder: The selected refractory high entropy alloy powder is TiNbHfZr with a particle size of 15-53 μm, and the aluminum alloy powder is AlSi10Mg with a particle size of 15-53 μm. A certain mass ratio of refractory high entropy alloy powder and aluminum alloy powder is weighed, wherein the mass fraction of TiNbHfZr powder is 2% and the remainder is AlSi10Mg powder. The mixture is mixed by ball milling. The stainless steel grinding balls used are 1 mm, 3 mm and 5 mm in size. The stainless steel balls are weighed at a mass ratio of 15:5:3 and the ball-to-material ratio is 1:1. The powder and grinding balls are added to the ball mill jar and mixed for 10 h. Argon gas is introduced as a protective gas and the rotation speed is 150 rpm. After the mixing is completed, the mixture is sieved and dried in a vacuum drying oven at 70 °C for 4 h to obtain the composite powder of TiNbHfZr and AlSi10Mg.

[0039] Step (2) Layered scanning additive manufacturing of aluminum-based composite materials: A 3D model is created and sliced ​​using 3D software. The composite powder from step (1) is spread evenly on the substrate of the SLM metal 3D printer's forming chamber. In this embodiment, 5083 aluminum alloy plate is used. The temperature is preheated to 180°C, and the protective atmosphere inside the printing chamber is argon. The printing process parameters are set as follows: laser power is 340W, scanning distance is 160μm, powder layer thickness is 30μm, and the scanning speed is controlled in stages: every 5 layers constitutes one cycle, the scanning speed A of the first layer is 1200mm / s (n=1 in this embodiment), and the scanning speeds of the next four layers are 1300mm / s, 1400mm / s, 1500mm / s, and 1600mm / s respectively. This cycle is repeated to print the aluminum-based composite material.

[0040] Microstructure characterization, hardness testing, and room temperature tensile mechanical property testing meeting national standards were performed on the prepared aluminum-based composite material. Significant improvements were observed: the yield strength and tensile strength of the aluminum-based composite material were greatly increased, reaching 319.57 MPa and 490.68 MPa respectively, while the elongation remained at 4.69%, and the hardness also increased to 165.3 HV. The metallographic structure of the aluminum-based composite material (and...) was observed... Figure 2 , 3 (Similar findings) No obvious defects were found within the structure, and the structure parallel to the construction direction consisted of fine equiaxed crystals.

[0041] Example 5

[0042] Step (1) Preparation of composite powder: The selected refractory high entropy alloy powder is TiNbZrTaV with a particle size of 15-53 μm, and the aluminum alloy powder is AlSi10Mg with a particle size of 15-53 μm. A certain mass ratio of refractory high entropy alloy powder and aluminum alloy powder is weighed, wherein the mass fraction of TiNbZrTaV powder is 2% and the remainder is AlSi10Mg powder. The powder is mixed using a V-type powder mixer, with argon gas as a protective gas, and the rotation speed is 200 rpm. After mixing, the powder is sieved and dried in a vacuum drying oven at 70℃ for 4 h to obtain the composite powder of TiNbZrTaV and AlSi10Mg.

[0043] Step (2) Layered scanning additive manufacturing of aluminum-based composite materials: A 3D model is created and sliced ​​using 3D software. The composite powder from step (1) is spread evenly on the substrate of the SLM metal 3D printer's forming chamber. In this embodiment, 5083 aluminum alloy plate is used. The temperature is preheated to 150°C, and the protective atmosphere inside the printing chamber is argon. The printing process parameters are set as follows: laser power is 370W, scanning distance is 140μm, powder layer thickness is 30μm, and the scanning speed is controlled in stages: every 5 layers constitutes one cycle, the scanning speed A of the first layer is 1100mm / s, and in this embodiment, n=2. The scanning speeds of the next four layers are 1300mm / s, 1500mm / s, 1700mm / s, and 1900mm / s, respectively. This cycle is repeated to print the aluminum-based composite material.

[0044] Microstructure characterization, hardness testing, and room temperature tensile mechanical property testing meeting national standards were performed on the prepared aluminum-based composite material. Significant improvements were observed: the yield strength and tensile strength of the aluminum-based composite material were greatly increased, reaching 323.69 MPa and 495.63 MPa respectively, while the elongation remained at 5.01%, and the hardness also increased to 169.66 HV. The metallographic structure of the aluminum-based composite material (and...) was observed... Figure 2 , 3 (Similarly) it was found that spherical refractory high-entropy alloy particles were distributed in the matrix, and the structure parallel to the construction direction became equiaxed crystals.

[0045] Example 6

[0046] Step (1) Preparation of composite powder: The selected refractory high entropy alloy powder is TiTaNbZrHf with a particle size of 15-53 μm, and the aluminum alloy powder is 2024 series aluminum alloy with a particle size of 15-53 μm. A certain mass ratio of refractory high entropy alloy powder and aluminum alloy powder is weighed, wherein the mass fraction of TiTaNbZrHf powder is 2%, and the rest is 2024 series aluminum alloy powder. The powder is mixed using a V-type powder mixer, and argon is introduced as a protective gas. The rotation speed is 180 rpm. After mixing, the powder is sieved and dried in a vacuum drying oven at 70℃ for 4 h to obtain composite powder of TiTaNbZrHf and AlSi10Mg.

[0047] Step (2) Layered scanning additive manufacturing of aluminum-based composite materials: A 3D model is created and sliced ​​using 3D software. The composite powder from step (1) is spread evenly on the substrate of the SLM metal 3D printer's forming chamber. In this embodiment, a 2024 aluminum alloy plate is used. The plate is preheated to 150°C, and the protective atmosphere inside the printing chamber is argon. The printing process parameters are set as follows: laser power is 380W, scanning distance is 150μm, powder layer thickness is 30μm, and the scanning speed is controlled in stages: every 5 layers constitutes one cycle, the scanning speed A of the first layer is 1200mm / s (n=2 in this embodiment), and the scanning speeds of the next four layers are 1400mm / s, 1600mm / s, 1800mm / s, and 2000mm / s, respectively. This cycle is repeated to print the aluminum-based composite material.

[0048] Microstructure characterization, hardness testing, and room temperature tensile mechanical property testing meeting national standards were performed on the prepared aluminum-based composite material. Significant improvements were observed: the yield strength and tensile strength of the aluminum-based composite material were greatly increased, reaching 269.56 MPa and 409.38 MPa respectively, while the elongation remained at 10.26%, and the hardness also increased to 142.9 HV. The metallographic structure of the aluminum-based composite material (and...) was observed... Figure 2 , 3 (Similarly) it was found that spherical refractory high-entropy alloy particles were distributed in the matrix, and the structure parallel to the construction direction became equiaxed crystals.

[0049] Example 7

[0050] Step (1) Preparation of composite powder: The selected refractory high entropy alloy powder is TiNbZrTa with a particle size of 15-53 μm, and the aluminum alloy powder is AlSi10Mg with a particle size of 45-90 μm. A certain mass ratio of refractory high entropy alloy powder and aluminum alloy powder is weighed, wherein the mass fraction of TiNbZrTa powder is 5% and the remainder is AlSi10Mg powder. The powder is mixed by ball milling. The stainless steel grinding balls used are 1 mm, 3 mm and 5 mm in size. The stainless steel balls are weighed at a mass ratio of 15:5:3 and the ball-to-material ratio is 1:1. The powder and grinding balls are added to the ball mill jar and mixed for 10 h. Argon gas is introduced as a protective gas and the rotation speed is 150 rpm. After the mixing is completed, the powder is sieved and dried in a vacuum drying oven at 70 °C for 4 h to obtain the composite powder of TiNbZrTa and AlSi10Mg.

[0051] Step (2) Layered scanning additive manufacturing of aluminum-based composite materials: A 3D model is created and sliced ​​using 3D software. The composite powder from step (1) is spread evenly on the substrate of the SLM metal 3D printer's forming chamber. In this embodiment, 5083 aluminum alloy plate is used. The temperature is preheated to 180°C, and the protective atmosphere inside the printing chamber is argon. The printing process parameters are set as follows: laser power is 350W, scanning distance is 150μm, powder layer thickness is 30μm, and the scanning speed is controlled in stages: every 5 layers constitutes one cycle, the scanning speed A of the first layer is 1400mm / s (n=1 in this embodiment), and the scanning speeds of the next four layers are 1500mm / s, 1600mm / s, 1700mm / s, and 1800mm / s respectively. This cycle is repeated to print the aluminum-based composite material.

[0052] Microstructure characterization, hardness testing, and room temperature tensile mechanical property testing meeting national standards were performed on the prepared aluminum-based composite material. Significant improvements were observed: the yield strength and tensile strength of the aluminum-based composite material were greatly increased, reaching 342.6 MPa and 522.69 MPa respectively, while the elongation remained at 4.03%, and the hardness also increased to 183.92 HV. The metallographic structure of the aluminum-based composite material (and...) was observed... Figure 2 , 3 (Similar findings) No obvious defects were found within the structure, and the structure parallel to the construction direction consisted of fine equiaxed crystals.

[0053] Example 8

[0054] Step (1) Preparation of composite powder: The selected refractory high entropy alloy powder is TiNbZrTa with a particle size of 15-53 μm, and the aluminum alloy powder is AlSi10Mg with a particle size of 15-53 μm. A certain mass ratio of refractory high entropy alloy powder and aluminum alloy powder is weighed, wherein the mass fraction of TiNbZrTa powder is 10% and the remainder is AlSi10Mg powder. The powder is mixed by ball milling. The ZrO2 grinding balls used are 1 mm, 3 mm and 5 mm in size. The ZrO2 grinding balls are weighed at a mass ratio of 15:5:3 and the ball-to-material ratio is 1:1. The powder and grinding balls are added to the ball mill jar and mixed for 4 h. Argon gas is introduced as a protective gas and the rotation speed is 150 rpm. After mixing, the powder is sieved and dried in a vacuum drying oven at 70 °C for 4 h to obtain the composite powder of TiNbZrTa and AlSi10Mg.

[0055] Step (2) Layered scanning additive manufacturing of aluminum-based composite materials: A 3D model is created and sliced ​​using 3D software. The composite powder from step (1) is spread evenly on the substrate of the SLM metal 3D printer's forming chamber. In this embodiment, 5083 aluminum alloy plate is used. The temperature is preheated to 150°C, and the protective atmosphere inside the printing chamber is argon. The printing process parameters are set as follows: laser power is 320W, scanning distance is 150μm, powder layer thickness is 30μm, and the scanning speed is controlled in stages: every 5 layers constitutes one cycle, the scanning speed A of the first layer is 1000mm / s, and in this embodiment, n=2. The scanning speeds of the next four layers are 1200mm / s, 1400mm / s, 1600mm / s, and 1800mm / s, respectively. This cycle is repeated to print the aluminum-based composite material.

[0056] Microstructure characterization, hardness testing, and room temperature tensile mechanical property testing meeting national standards were performed on the prepared aluminum-based composite material. Significant improvements were observed: the yield strength and tensile strength of the aluminum-based composite material were greatly increased, reaching 362.59 MPa and 550.68 MPa respectively, while the elongation remained at 3.43%, and the hardness also increased to 220.69 HV. The metallographic structure of the aluminum-based composite material (and...) was observed... Figure 2 , 3 (Similarly) it was found that more spherical particles were distributed in the matrix, and the interface between the refractory high-entropy alloy and the aluminum matrix was well bonded.

[0057] Comparative example:

[0058] This comparative example prepared an AlSi10Mg alloy. Unlike Example 1, no refractory high-entropy alloy was added as a reinforcing phase. The printing process was the same as in Example 1.

[0059] Figure 4 The metallographic image shown is parallel to the construction direction, representing a typical columnar crystal growth perpendicular to the melt pool direction. The room temperature tensile mechanical property test results for the comparative example meet national standards. Figure 5 As shown by the dashed line. The mechanical properties of the refractory high-entropy alloy-reinforced aluminum matrix composites prepared in Examples 1, 2, 3, 4, 5, 7, and 8 are significantly improved compared to AlSi10Mg alloy, while still retaining a certain degree of plasticity. This indicates that the addition of the refractory high-entropy alloy and the step-by-step controlled scanning speed printing method can effectively change the grain growth mode, reduce the anisotropy of the composite material, and thus improve the performance of the composite material.

[0060] The embodiments described above are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments. Any obvious improvements, substitutions or modifications that can be made by those skilled in the art without departing from the essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A layered scanning additive manufacturing method for aluminum-based composite materials reinforced with refractory high-entropy alloy particles, characterized in that, Includes the following steps: (1) Preparation of composite powder: Weigh out refractory high entropy alloy powder and aluminum alloy powder respectively, mix them evenly with a powder mixing device, introduce protective gas, sieve through a standard sieve and dry to obtain composite powder of refractory high entropy alloy and aluminum alloy; the matrix of the aluminum matrix composite material reinforced by refractory high entropy alloy particles is various aluminum alloys, including cast aluminum alloys and wrought aluminum alloys; the reinforcing phase is a refractory high entropy alloy, including TiNbZrTa system, WTaMoNb system, HfNbZrTa system, TiTaNbV system or TiNbHfZr system high entropy alloys; the cast aluminum alloy is Al-Si system, Al-Cu system, Al-Mg system or Al-Zn system; the wrought aluminum alloy is I-series, 2-series, 4-series, 5-series or 6-series aluminum alloys; (2) Layered scanning additive manufacturing of aluminum-based composite materials: Three-dimensional modeling is performed and slices are made; composite powder is spread on the substrate of the forming chamber of the SLM metal 3D printer, the substrate is preheated in a protective gas atmosphere, the laser power and scanning spacing are adjusted, and the scanning speed is controlled in stages: every 5 layers is a cycle, the scanning speed of the first layer is A mm / s, the scanning speed of the second layer is A+n×100 mm / s, the scanning speed of the third layer is A+2n×100 mm / s, the scanning speed of the fourth layer is A+3n×100 mm / s, the scanning speed of the fifth layer is A+4n×100 mm / s, and the scanning speed of the first layer of the next cycle is still A mm / s, and so on, so that the laser periodically scans the powder bed layer by layer to print the aluminum-based composite material; the graded control of the scanning speed: where n=1, 2 or 3 and n is the same number throughout the printing process, the scanning speed A mm / s and A+4n×100 mm / s are both in the range of 900~2100 mm / s.

2. The method according to claim 1, characterized in that, In step (1), the mass fraction of the refractory high entropy alloy powder is between 1% and 10%, the mass fraction of the aluminum alloy powder is between 90% and 99%, and the sum of the two is equal to 100%; the refractory high entropy alloy powder is spherical with a particle size between 1 and 53 μm, and the aluminum alloy powder is spherical with a particle size between 1 and 90 μm.

3. The method according to claim 1, characterized in that, In step (1), the powder mixing equipment is a ball mill or a V-type powder mixer, wherein the ball milling time is 4~10 h, the rotation speed is 120~200 rpm, the grinding balls are ZrO2 grinding balls or stainless steel grinding balls, the grinding ball size is 1~5 mm, the ball-to-material ratio is 1:1~5:1, and the powder mixing time of the V-type powder mixer is 4~8 h; after the powder is mixed evenly, it is sieved and dried in a vacuum environment of 70~100 ℃ for 3~6 h.

4. The method according to claim 1, characterized in that, In step (1), the protective gas is nitrogen or argon.

5. The method according to claim 1, characterized in that, In step (2), the substrate used in the printing process is a 1-series, 2-series, 4-series, 5-series or 6-series aluminum alloy. The substrate is preheated in a nitrogen or argon atmosphere at a temperature of 100 ℃ to 200 ℃.

6. The method according to claim 1, characterized in that, In step (2), the laser power is 300~380W, the scanning interval is 100~160 μm, and the powder layer thickness is 20~40 μm.

7. An aluminum-based composite material reinforced with refractory high-entropy alloy particles is prepared by the method described in any one of claims 1 to 6.

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