Aluminum alloy material for automobile and preparation method of aluminum alloy material

Abstract

The invention belongs to the field of aluminum alloy materials, and particularly relates to an aluminum alloy material for an automobile and a preparation method thereof. Through the composite foaming structure of the TiHfoaming agent and the hollow glass beads, the density of the prepared aluminum alloy material for the automobile is greatly reduced, and compared with a traditional aluminum alloy, the mass of an automobile body can be reduced. Meanwhile, prefabricated Sc-Zr reinforced powder and uniformly dispersed Sc-Zr nano precipitated phases are adopted for pinning dislocation, the bearing capacity of a matrix is enhanced, the precipitation strengthening efficiency and tensile strength of the material are improved, crack initiation and expansion are hindered through a layered structure of SiC and graphene composite powder, stress distribution is optimized, the interface bonding strength is improved, and the fatigue life is prolonged. The low-density aluminum alloy material with the high mechanical property is obtained by combining the low-density aluminum alloy material and the low-density aluminum alloy material, the aluminum alloy material is used in the field of automobiles, the weight of an automobile body can be greatly reduced, the balance of light weight and safety is achieved, and a feasible solution is provided for new energy automobile and lightweight automobile body design.

Description

Technical Field

[0001] This invention belongs to the field of aluminum alloy materials, specifically an aluminum alloy material for automobiles and its preparation method. Background Technology

[0002] With the global energy crisis and increasingly stringent environmental regulations, lightweighting of automobiles has become a key technological path to improve fuel economy, reduce emissions, and increase the driving range of new energy vehicles. Aluminum alloys, due to their excellent specific strength, good formability, and corrosion resistance, are considered one of the preferred materials for achieving automotive lightweighting. Replacing traditional steel with aluminum alloys in body structural components, body panels, and chassis components can significantly reduce the overall vehicle weight.

[0003] However, when pursuing higher strength to meet vehicle safety requirements, traditional cast or forged aluminum alloys often require the addition of large amounts of alloying elements or the use of complex strengthening processes, which may lead to increased material costs, decreased plasticity, or deteriorated processing performance. More importantly, conventional aluminum alloys have limited potential for density reduction, making it difficult to meet the automotive industry's urgent need for extreme lightweighting. In recent years, foamed aluminum alloys have shown great promise for lightweighting due to their extremely low density; however, foamed aluminum alloys prepared by existing technologies generally suffer from insufficient strength, uneven cell structure, and mechanical properties (especially tensile strength and fatigue life) that are difficult to meet the stringent requirements of vehicle body structural components. In addition, regarding the addition of reinforcing phases, rare earth elements (such as Sc and Zr) added in traditional smelting processes are prone to segregation, making it difficult to form fine, uniformly dispersed reinforcing phases; while directly added nano-reinforcing materials (such as SiC and graphene) are prone to agglomeration, leading to weakened interfacial bonding and failing to fully exert their reinforcing and toughening effects, thus limiting the improvement of the material's overall performance.

[0004] Therefore, developing a novel aluminum alloy material for automobiles that combines low density, high strength, good toughness, and excellent fatigue performance, along with its efficient preparation method, to effectively balance lightweighting and safety, has become a key technical challenge that urgently needs to be addressed in the field of automotive materials. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an aluminum alloy material for automobiles and its preparation method.

[0006] An aluminum alloy material for automobiles, by weight, is composed of the following raw materials:

[0007] 82-83 parts of matrix alloy powder;

[0008] 3-4 parts Sc-Zr enhancement powder;

[0009] 0.5-1 parts SiC@graphene composite powder;

[0010] 1-2 parts TiH2 foaming agent;

[0011] 4-6 parts hollow glass microspheres;

[0012] 7-8 parts aluminum powder.

[0013] Preferably, the method for preparing the matrix alloy powder includes the following steps:

[0014] By weight, 89-90 parts of aluminum powder, 6-7 parts of zinc powder, 2-3 parts of magnesium powder, and 1-2 parts of copper powder are mixed, melted at 840-860℃, atomized by argon pressure of 2.9-3.1 MPa, and cooled to obtain the matrix alloy powder.

[0015] Preferably, the preparation method of the Sc-Zr reinforced powder includes the following steps:

[0016] By mass, 89-91 parts of aluminum powder, 4-6 parts of Sc powder, and 4-6 parts of Zr powder are mixed and ball-milled with zirconia balls in an argon atmosphere for 20-30 hours. The ball-to-material ratio is 10:(1-2), and the rotation speed is 300-400 rpm to obtain the Sc-Zr reinforced powder.

[0017] Preferably, the preparation method of the SiC@graphene composite powder includes the following steps:

[0018] Nano-Si powder and graphene were ultrasonically dispersed in anhydrous ethanol for 20-40 min, with the concentration of nano-Si powder being 0.4-0.5 wt% and the concentration of graphene being 0.1-0.2 wt%. Then, the mixture was spray-dried and calcined at 590-610℃ under vacuum for 20-40 min to obtain SiC@graphene composite powder.

[0019] This invention also provides a method for preparing aluminum alloy materials for automobiles, comprising the following steps:

[0020] (1) Mix 82-83 parts of matrix alloy powder, 3-4 parts of Sc-Zr reinforcing powder, 0.5-1 parts of SiC@graphene composite powder, 1-2 parts of TiH2 foaming agent, 4-6 parts of hollow glass microspheres, and 7-8 parts of aluminum powder evenly, and perform cold isostatic pressing at a pressure of 200 MPa to obtain a green blank;

[0021] (2) The green blank obtained in step (1) is placed at 590-610℃ and under vacuum for 1-3 hours. After cooling to room temperature, the surface area is scanned with a fiber laser with a wavelength of 1064 nm and sealed to obtain an aluminum alloy plate.

[0022] (3) Place the aluminum alloy plate obtained in step (2) under vacuum for 1-2 hours to degas it, then place it under 465-470℃ and argon for 15-25 minutes, then raise the temperature to 480-485℃ and calcine for 10-20 minutes, then lower the temperature to 470-480℃ and calcine for 20-30 minutes, then immediately take it out and place it in hot water at 68-72℃ to complete water quenching, and finally place it under 115-125℃ and argon for 24-48 hours to stabilize it. After cooling to room temperature, perform micro-arc oxidation on the surface to obtain the aluminum alloy material for automobiles.

[0023] The power of the fiber laser scanning in step (2) is 600-800 W, the scanning speed is 9-11 mm / s, and the spot diameter is 0.1-0.3 mm.

[0024] The beneficial effects of this invention are:

[0025] This invention significantly reduces the density of automotive aluminum alloy materials through a composite foaming structure of TiH2 foaming agent and hollow glass microspheres, resulting in a reduction in vehicle body weight compared to traditional aluminum alloys. Simultaneously, this invention employs pre-formulated Sc-Zr reinforcing powder, where uniformly dispersed Sc-Zr nano-precipitates pin dislocations, enhancing the matrix's load-bearing capacity and improving precipitation strengthening efficiency and tensile strength. Furthermore, the layered structure of SiC@graphene composite powder inhibits crack initiation and propagation, optimizes stress distribution, and improves interfacial bonding strength and fatigue life. Combining these two methods in the preparation of low-density aluminum alloy materials yields a low-density, high-mechanical-performance aluminum alloy material. Its application in the automotive field can significantly reduce vehicle body weight, achieving a balance between lightweighting and safety, and providing a feasible solution for new energy vehicles and lightweight vehicle body design. Detailed Implementation

[0026] TiH2 foaming agent, product number: M25986, Shanghai Mairui Biochemical Technology Co., Ltd.

[0027] Nano Si powder, item number: YM-Si005, Yumu (Ningbo) New Materials Co., Ltd.

[0028] Graphene, item number: YK5504, Hubei Yongkuo Technology Co., Ltd.

[0029] Zirconia spheres, size: 1mm, item number: MF-LUD, Ikedaya Industrial (Shenzhen) Co., Ltd. Example 1

[0030] An aluminum alloy material for automobiles, by weight, is composed of the following raw materials:

[0031] 82.3 parts of matrix alloy powder;

[0032] 3.25 parts Sc-Zr enhanced powder;

[0033] 0.6 parts SiC@graphene composite powder;

[0034] 1.5 parts TiH2 foaming agent;

[0035] 5 portions of hollow glass microspheres;

[0036] 7.35 parts aluminum powder.

[0037] The method for preparing matrix alloy powder includes the following steps:

[0038] By weight, 89.64 parts aluminum powder, 6.54 parts zinc powder, 2.21 parts magnesium powder, and 1.61 parts copper powder were mixed, melted at 850°C, atomized by argon pressure at 3 MPa, and cooled to obtain the matrix alloy powder.

[0039] The preparation method of Sc-Zr reinforced powder includes the following steps:

[0040] By weight, 90 parts aluminum powder, 5 parts Sc powder, and 5 parts Zr powder were mixed and ball-milled with zirconia balls for 30 hours in an argon atmosphere. The ball-to-material ratio was 10:1 and the rotation speed was 350 rpm to obtain Sc-Zr reinforced powder.

[0041] The preparation method of SiC@graphene composite powder includes the following steps:

[0042] Nano-Si powder and graphene were ultrasonically dispersed in anhydrous ethanol for 30 min, with the concentration of nano-Si powder being 0.42 wt% and the concentration of graphene being 0.18 wt%. Then, the mixture was spray-dried and calcined at 600℃ under vacuum for 30 min to obtain SiC@graphene composite powder.

[0043] This invention also provides a method for preparing aluminum alloy materials for automobiles, comprising the following steps:

[0044] (1) Mix 82.3 parts of matrix alloy powder, 3.25 parts of Sc-Zr reinforcing powder, 0.6 parts of SiC@graphene composite powder, 1.5 parts of TiH2 foaming agent, 5 parts of hollow glass microspheres and 7.35 parts of aluminum powder evenly, and perform cold isostatic pressing at a pressure of 200 MPa to obtain a green blank;

[0045] (2) The green blank obtained in step (1) was calcined at 600°C under vacuum for 2 hours. After cooling to room temperature, the surface area was scanned with a fiber laser with a wavelength of 1064 nm and sealed to obtain an aluminum alloy plate.

[0046] (3) The aluminum alloy plate obtained in step (2) is placed in a vacuum environment for degassing for 1 hour, then placed in an argon environment at 465°C for 20 minutes, then heated to 480°C for 15 minutes, then cooled to 475°C for 25 minutes, and immediately taken out and placed in hot water at 70°C to complete water quenching. Finally, it is placed in an argon environment at 120°C for 24 hours to stabilize. After cooling to room temperature, the surface is subjected to micro-arc oxidation to obtain the aluminum alloy material for automobiles.

[0047] The power of the fiber laser scanning in step (2) is 800 W, the scanning speed is 10 mm / s, and the spot diameter is 0.2 mm. Example 2

[0048] An aluminum alloy material for automobiles, by weight, is composed of the following raw materials:

[0049] 82.3 parts of matrix alloy powder;

[0050] 0.6 parts SiC@graphene composite powder;

[0051] 1.5 parts TiH2 foaming agent;

[0052] 5 portions of hollow glass microspheres;

[0053] 7.35 parts aluminum powder.

[0054] The method for preparing matrix alloy powder includes the following steps:

[0055] By weight, 89.64 parts aluminum powder, 6.54 parts zinc powder, 2.21 parts magnesium powder, and 1.61 parts copper powder were mixed, melted at 850°C, atomized by argon pressure at 3 MPa, and cooled to obtain the matrix alloy powder.

[0056] The preparation method of SiC@graphene composite powder includes the following steps:

[0057] Nano-Si powder and graphene were ultrasonically dispersed in anhydrous ethanol for 30 min, with the concentration of nano-Si powder being 0.42 wt% and the concentration of graphene being 0.18 wt%. Then, the mixture was spray-dried and calcined at 600℃ under vacuum for 30 min to obtain SiC@graphene composite powder.

[0058] This invention also provides a method for preparing aluminum alloy materials for automobiles, comprising the following steps:

[0059] (1) Mix 82.3 parts of matrix alloy powder, 0.6 parts of SiC@graphene composite powder, 1.5 parts of TiH2 foaming agent, 5 parts of hollow glass microspheres and 7.35 parts of aluminum powder evenly, and perform cold isostatic pressing at a pressure of 200 MPa to obtain a green blank.

[0060] (2) The green blank obtained in step (1) was calcined at 600°C under vacuum for 2 hours. After cooling to room temperature, the surface area was scanned with a fiber laser with a wavelength of 1064 nm and sealed to obtain an aluminum alloy plate.

[0061] (3) The aluminum alloy plate obtained in step (2) is placed in a vacuum environment for degassing for 1 hour, then placed in an argon environment at 465°C for 20 minutes, then heated to 480°C for 15 minutes, then cooled to 475°C for 25 minutes, and immediately taken out and placed in hot water at 70°C to complete water quenching. Finally, it is placed in an argon environment at 120°C for 24 hours to stabilize. After cooling to room temperature, the surface is subjected to micro-arc oxidation to obtain the aluminum alloy material for automobiles.

[0062] Step (2) The power of the fiber laser scanning is 800 W, the scanning speed is 10 mm / s, and the spot diameter is 0.2 mm. Example 3

[0063] An aluminum alloy material for automobiles, by weight, is composed of the following raw materials:

[0064] 82.3 parts of matrix alloy powder;

[0065] 3.25 parts Sc-Zr enhanced powder;

[0066] 1.5 parts TiH2 foaming agent;

[0067] 5 portions of hollow glass microspheres;

[0068] 7.35 parts aluminum powder.

[0069] The method for preparing matrix alloy powder includes the following steps:

[0070] By weight, 89.64 parts aluminum powder, 6.54 parts zinc powder, 2.21 parts magnesium powder, and 1.61 parts copper powder were mixed, melted at 850°C, atomized by argon pressure at 3 MPa, and cooled to obtain the matrix alloy powder.

[0071] The preparation method of Sc-Zr reinforced powder includes the following steps:

[0072] By weight, 90 parts aluminum powder, 5 parts Sc powder, and 5 parts Zr powder were mixed and ball-milled with zirconia balls for 30 hours in an argon atmosphere. The ball-to-material ratio was 10:1 and the rotation speed was 350 rpm to obtain Sc-Zr reinforced powder.

[0073] This invention also provides a method for preparing aluminum alloy materials for automobiles, comprising the following steps:

[0074] (1) Mix 82.3 parts of matrix alloy powder, 3.25 parts of Sc-Zr reinforcing powder, 1.5 parts of TiH2 foaming agent, 5 parts of hollow glass microspheres and 7.35 parts of aluminum powder evenly, and perform cold isostatic pressing at a pressure of 200 MPa to obtain a green blank;

[0075] (2) The green blank obtained in step (1) was calcined at 600°C under vacuum for 2 hours. After cooling to room temperature, the surface area was scanned with a fiber laser with a wavelength of 1064 nm and sealed to obtain an aluminum alloy plate.

[0076] (3) The aluminum alloy plate obtained in step (2) is placed in a vacuum environment for degassing for 1 hour, then placed in an argon environment at 465°C for 20 minutes, then heated to 480°C for 15 minutes, then cooled to 475°C for 25 minutes, and immediately taken out and placed in hot water at 70°C to complete water quenching. Finally, it is placed in an argon environment at 120°C for 24 hours to stabilize. After cooling to room temperature, the surface is subjected to micro-arc oxidation to obtain aluminum alloy material for automobiles.

[0077] Step (2) The power of the fiber laser scanning is 800 W, the scanning speed is 10 mm / s, and the spot diameter is 0.2 mm. Example 4

[0078] An aluminum alloy material for automobiles, by weight, is composed of the following raw materials:

[0079] 82.3 parts of matrix alloy powder;

[0080] 1.5 parts TiH2 foaming agent;

[0081] 5 portions of hollow glass microspheres;

[0082] 7.35 parts aluminum powder.

[0083] The method for preparing matrix alloy powder includes the following steps:

[0084] By weight, 89.64 parts aluminum powder, 6.54 parts zinc powder, 2.21 parts magnesium powder, and 1.61 parts copper powder were mixed, melted at 850°C, atomized by argon pressure at 3 MPa, and cooled to obtain the matrix alloy powder.

[0085] This invention also provides a method for preparing aluminum alloy materials for automobiles, comprising the following steps:

[0086] (1) Mix 82.3 parts of matrix alloy powder, 1.5 parts of TiH2 foaming agent, 5 parts of hollow glass microspheres and 7.35 parts of aluminum powder evenly, and perform cold isostatic pressing at a pressure of 200 MPa to obtain a green blank;

[0087] (2) The green blank obtained in step (1) was calcined at 600°C under vacuum for 2 hours. After cooling to room temperature, the surface area was scanned with a fiber laser with a wavelength of 1064 nm and sealed to obtain an aluminum alloy plate.

[0088] (3) The aluminum alloy plate obtained in step (2) is placed in a vacuum environment for degassing for 1 hour, then placed in an argon environment at 465°C for 20 minutes, then heated to 480°C for 15 minutes, then cooled to 475°C for 25 minutes, and immediately taken out and placed in hot water at 70°C to complete water quenching. Finally, it is placed in an argon environment at 120°C for 24 hours to stabilize. After cooling to room temperature, the surface is subjected to micro-arc oxidation to obtain aluminum alloy material for automobiles.

[0089] Step (2) The power of the fiber laser scanning is 800 W, the scanning speed is 10 mm / s, and the spot diameter is 0.2 mm. Example 5

[0090] An aluminum alloy material for automobiles, by weight, is composed of the following raw materials:

[0091] 82.3 parts of matrix alloy powder;

[0092] 0.1625 parts Sc powder;

[0093] 0.1625 parts Zr powder;

[0094] 0.6 parts SiC@graphene composite powder;

[0095] 1.5 parts TiH2 foaming agent;

[0096] 5 portions of hollow glass microspheres;

[0097] 10.275 parts aluminum powder.

[0098] The method for preparing matrix alloy powder includes the following steps:

[0099] By weight, 89.64 parts aluminum powder, 6.54 parts zinc powder, 2.21 parts magnesium powder, and 1.61 parts copper powder were mixed, melted at 850°C, atomized by argon pressure at 3 MPa, and cooled to obtain the matrix alloy powder.

[0100] The preparation method of SiC@graphene composite powder includes the following steps:

[0101] Nano-Si powder and graphene were ultrasonically dispersed in anhydrous ethanol for 30 min, with the concentration of nano-Si powder being 0.42 wt% and the concentration of graphene being 0.18 wt%. Then, the mixture was spray-dried and calcined at 600℃ under vacuum for 30 min to obtain SiC@graphene composite powder.

[0102] This invention also provides a method for preparing aluminum alloy materials for automobiles, comprising the following steps:

[0103] (1) Mix 82.3 parts of matrix alloy powder, 0.1625 parts of Sc powder, 0.1625 parts of Zr powder, 0.6 parts of SiC@graphene composite powder, 1.5 parts of TiH2 foaming agent, 5 parts of hollow glass microspheres and 10.275 parts of aluminum powder evenly, and perform cold isostatic pressing at a pressure of 200 MPa to obtain a green blank;

[0104] (2) The green blank obtained in step (1) was calcined at 600°C under vacuum for 2 hours. After cooling to room temperature, the surface area was scanned with a fiber laser with a wavelength of 1064 nm and sealed to obtain an aluminum alloy plate.

[0105] (3) The aluminum alloy plate obtained in step (2) is placed in a vacuum environment for degassing for 1 hour, then placed in an argon environment at 465°C for 20 minutes, then heated to 480°C for 15 minutes, then cooled to 475°C for 25 minutes, and immediately taken out and placed in hot water at 70°C to complete water quenching. Finally, it is placed in an argon environment at 120°C for 24 hours to stabilize. After cooling to room temperature, the surface is subjected to micro-arc oxidation to obtain aluminum alloy material for automobiles.

[0106] Step (2) The power of the fiber laser scanning is 800 W, the scanning speed is 10 mm / s, and the spot diameter is 0.2 mm. Example 6

[0107] An aluminum alloy material for automobiles, by weight, is composed of the following raw materials:

[0108] 82.3 parts of matrix alloy powder;

[0109] 3.25 parts Sc-Zr enhanced powder;

[0110] 0.42 parts nano-Si powder;

[0111] 0.18 parts graphene;

[0112] 1.5 parts TiH2 foaming agent;

[0113] 5 portions of hollow glass microspheres;

[0114] 7.35 parts aluminum powder.

[0115] The method for preparing matrix alloy powder includes the following steps:

[0116] By weight, 89.64 parts aluminum powder, 6.54 parts zinc powder, 2.21 parts magnesium powder, and 1.61 parts copper powder were mixed, melted at 850°C, atomized by argon pressure at 3 MPa, and cooled to obtain the matrix alloy powder.

[0117] The preparation method of Sc-Zr reinforced powder includes the following steps:

[0118] By weight, 90 parts aluminum powder, 5 parts Sc powder, and 5 parts Zr powder were mixed and ball-milled with zirconia balls for 30 hours in an argon atmosphere. The ball-to-material ratio was 10:1 and the rotation speed was 350 rpm to obtain Sc-Zr reinforced powder.

[0119] This invention also provides a method for preparing aluminum alloy materials for automobiles, comprising the following steps:

[0120] (1) Mix 82.3 parts of matrix alloy powder, 3.25 parts of Sc-Zr reinforcing powder, 0.42 parts of nano Si powder, 0.18 parts of graphene, 1.5 parts of TiH2 foaming agent, 5 parts of hollow glass microspheres and 7.35 parts of aluminum powder evenly, and perform cold isostatic pressing at a pressure of 200 MPa to obtain a green blank;

[0121] (2) The green blank obtained in step (1) was calcined at 600°C under vacuum for 2 hours. After cooling to room temperature, the surface area was scanned with a fiber laser with a wavelength of 1064 nm and sealed to obtain an aluminum alloy plate.

[0122] (3) The aluminum alloy plate obtained in step (2) is placed in a vacuum environment for degassing for 1 hour, then placed in an argon environment at 465°C for 20 minutes, then heated to 480°C for 15 minutes, then cooled to 475°C for 25 minutes, and immediately taken out and placed in hot water at 70°C to complete water quenching. Finally, it is placed in an argon environment at 120°C for 24 hours to stabilize. After cooling to room temperature, the surface is subjected to micro-arc oxidation to obtain the aluminum alloy material for automobiles.

[0123] Step (2) The power of the fiber laser scanning is 800 W, the scanning speed is 10 mm / s, and the spot diameter is 0.2 mm.

[0124] Comparative Example 1

[0125] An aluminum alloy material for automobiles, by weight, is composed of the following raw materials:

[0126] 100 parts of matrix alloy powder;

[0127] The method for preparing matrix alloy powder includes the following steps:

[0128] By weight, 89.64 parts aluminum powder, 6.54 parts zinc powder, 2.21 parts magnesium powder, and 1.61 parts copper powder were mixed, melted at 850°C, atomized by argon pressure at 3 MPa, and cooled to obtain the matrix alloy powder.

[0129] This invention also provides a method for preparing aluminum alloy materials for automobiles, comprising the following steps:

[0130] (1) 100 parts of matrix alloy powder were cold isostatically pressed at a pressure of 200 MPa to obtain a green blank;

[0131] (2) The green blank obtained in step (1) was calcined at 600°C under vacuum for 2 hours. After cooling to room temperature, the surface area was scanned with a fiber laser with a wavelength of 1064 nm and sealed to obtain an aluminum alloy plate.

[0132] (3) The aluminum alloy plate obtained in step (2) is placed in a vacuum environment for degassing for 1 hour, then placed in an argon environment at 465°C for 20 minutes, then heated to 480°C for 15 minutes, then cooled to 475°C for 25 minutes, and immediately taken out and placed in hot water at 70°C to complete water quenching. Finally, it is placed in an argon environment at 120°C for 24 hours to stabilize. After cooling to room temperature, the surface is subjected to micro-arc oxidation to obtain aluminum alloy material for automobiles.

[0133] Step (2) The power of the fiber laser scanning is 800 W, the scanning speed is 10 mm / s, and the spot diameter is 0.2 mm.

[0134] Comparative Example 2

[0135] An aluminum alloy material for automobiles, by weight, is composed of the following raw materials:

[0136] 82.3 parts of matrix alloy powder;

[0137] 3.25 parts Sc-Zr enhanced powder;

[0138] 0.6 parts SiC@graphene composite powder;

[0139] 7.35 parts aluminum powder.

[0140] The method for preparing matrix alloy powder includes the following steps:

[0141] By weight, 89.64 parts aluminum powder, 6.54 parts zinc powder, 2.21 parts magnesium powder, and 1.61 parts copper powder were mixed, melted at 850°C, atomized by argon pressure at 3 MPa, and cooled to obtain the matrix alloy powder.

[0142] The preparation method of Sc-Zr reinforced powder includes the following steps:

[0143] By weight, 90 parts aluminum powder, 5 parts Sc powder, and 5 parts Zr powder were mixed and ball-milled with zirconia balls for 30 hours in an argon atmosphere. The ball-to-material ratio was 10:1 and the rotation speed was 350 rpm to obtain Sc-Zr reinforced powder.

[0144] The preparation method of SiC@graphene composite powder includes the following steps:

[0145] Nano-Si powder and graphene were ultrasonically dispersed in anhydrous ethanol for 30 min, with the concentration of nano-Si powder being 0.42 wt% and the concentration of graphene being 0.18 wt%. Then, the mixture was spray-dried and calcined at 600℃ under vacuum for 30 min to obtain SiC@graphene composite powder.

[0146] This invention also provides a method for preparing aluminum alloy materials for automobiles, comprising the following steps:

[0147] (1) Mix 82.3 parts of matrix alloy powder, 3.25 parts of Sc-Zr reinforcing powder, 0.6 parts of SiC@graphene composite powder and 7.35 parts of aluminum powder evenly, and perform cold isostatic pressing at a pressure of 200 MPa to obtain a green blank;

[0148] (2) The green blank obtained in step (1) was calcined at 600°C under vacuum for 2 hours. After cooling to room temperature, the surface area was scanned with a fiber laser with a wavelength of 1064 nm and sealed to obtain an aluminum alloy plate.

[0149] (3) The aluminum alloy plate obtained in step (2) is placed in a vacuum environment for degassing for 1 hour, then placed in an argon environment at 465°C for 20 minutes, then heated to 480°C for 15 minutes, then cooled to 475°C for 25 minutes, and immediately taken out and placed in hot water at 70°C to complete water quenching. Finally, it is placed in an argon environment at 120°C for 24 hours to stabilize. After cooling to room temperature, the surface is subjected to micro-arc oxidation to obtain aluminum alloy material for automobiles.

[0150] Step (2) The power of the fiber laser scanning is 800 W, the scanning speed is 10 mm / s, and the spot diameter is 0.2 mm.

[0151] Test Example 1

[0152] The tensile strength test was conducted on the aluminum alloy materials for automobiles prepared in Examples 1-6 and Comparative Examples 1-2 of this invention, in accordance with GB / T 228.1-2021 "Metallic materials - Tensile testing - Part 1: Test method at room temperature". The results are shown in Table 1.

[0153] Table 1: Tensile Strength Test Results

[0154]

[0155] Test Example 2

[0156] Fatigue life testing was conducted on the aluminum alloy materials for automobiles prepared in Examples 1-6 and Comparative Examples 1-2 of this invention, with a stress of 300 MPa, in accordance with GB / T 3075-2021 "Method for controlling axial force in fatigue testing of metallic materials". The results are shown in Table 2.

[0157] Table 2: Fatigue Life Test Results

[0158]

[0159] Test Example 3

[0160] Density testing was performed on the aluminum alloy materials for automobiles prepared in Examples 1-6 and Comparative Examples 1-2 of this invention, in accordance with GB / T 3850-2015 "Determination of Density of Dense Sintered Metallic Materials". The results are shown in Table 3.

[0161] Table 3: Material Density

[0162]

[0163] As shown in Table 3, the density of the automotive aluminum alloy material prepared in the examples is significantly lower than that of the comparative example. Due to the use of TiH2 foaming agent and hollow glass microspheres, its lower density means a significant reduction in vehicle weight, thereby significantly improving fuel efficiency, reducing carbon emissions, and enhancing acceleration and handling performance. Simultaneously, through the synergistic effect of Sc-Zr reinforcing powder and SiC@graphene composite powder, the material maintains excellent mechanical properties under lightweight conditions, as shown in Tables 1 and 2: tensile strength > 300 MPa, fatigue life > This achieves a balance between lightweighting and safety, providing a feasible solution for new energy vehicles and lightweight vehicle body design.

[0164] Furthermore, as can be seen from Tables 1 and 2, compared with Examples 2-6, the automotive aluminum alloy material prepared in Example 1 of this invention has the best mechanical properties, with a tensile strength as high as 520 MPa and a fatigue life reaching [missing information]. Compared to Example 1, the automotive aluminum alloy material prepared in Example 2 lacked Sc-Zr reinforcing powder, resulting in a decrease in its mechanical properties. This invention suggests that Sc-Zr reinforcing powder can significantly improve strength by forming Al3(Sc,Zr) nano-precipitates, while also hindering crack propagation and improving fatigue life. The automotive aluminum alloy material prepared in Example 3 lacked SiC@graphene composite powder. SiC@graphene composite powder can improve strength through particle reinforcement and interface strengthening; therefore, the mechanical properties of the automotive aluminum alloy material prepared in Example 3 were also inferior to those in Example 1. The automotive aluminum alloy material prepared in Example 4 lacked both Sc-Zr reinforcing powder and SiC@graphene composite powder, resulting in a further decrease in its mechanical properties compared to Examples 2 and 3. This demonstrates the synergistic effect of Sc-Zr reinforcing powder and SiC@graphene composite powder; their combined use can significantly improve the mechanical properties of the material. Example 5 directly added Sc powder and Zr powder, and Example 6 directly added nano-Si powder and graphene. Due to their uneven dispersion, the strengthening effect was significantly reduced.

[0165] This invention utilizes pre-formulated Sc-Zr reinforcing powder, where uniformly dispersed Sc-Zr nano-precipitates pin dislocations, enhancing the matrix's load-bearing capacity and improving precipitation strengthening efficiency and tensile strength. Furthermore, the layered structure of the SiC@graphene composite powder inhibits crack initiation and propagation, optimizes stress distribution, and improves interfacial bonding strength and fatigue life. Combining these two methods in the preparation of low-density aluminum alloys yields a low-density, high-mechanical-performance aluminum alloy material. Its application in the automotive field can significantly reduce vehicle weight, achieving a balance between lightweighting and safety, and providing a feasible solution for new energy vehicles and lightweight vehicle body design.

Claims

1. An aluminum alloy material for automobiles, characterized in that, By weight, it consists of the following raw materials: 82-83 parts of matrix alloy powder; 3-4 parts Sc-Zr enhancement powder; 0.5-1 parts SiC@graphene composite powder; 1-2 parts TiH2 foaming agent; 4-6 parts hollow glass microspheres; 7-8 parts aluminum powder.

2. The automotive aluminum alloy material as described in claim 1, characterized in that, The method for preparing the matrix alloy powder includes the following steps: By weight, 89-90 parts of aluminum powder, 6-7 parts of zinc powder, 2-3 parts of magnesium powder, and 1-2 parts of copper powder are mixed, melted at 840-860℃, atomized by argon pressure of 2.9-3.1 MPa, and cooled to obtain the matrix alloy powder.

3. The automotive aluminum alloy material as described in claim 1, characterized in that, The preparation method of the Sc-Zr reinforced powder includes the following steps: By mass, 89-91 parts of aluminum powder, 4-6 parts of Sc powder, and 4-6 parts of Zr powder are mixed and ball-milled with zirconia balls in an argon atmosphere for 20-30 hours. The ball-to-material ratio is 10:(1-2), and the rotation speed is 300-400 rpm to obtain the Sc-Zr reinforced powder.

4. The automotive aluminum alloy material as described in claim 1, characterized in that, The preparation method of the SiC@graphene composite powder includes the following steps: Nano-Si powder and graphene were ultrasonically dispersed in anhydrous ethanol for 20-40 min, with the concentration of nano-Si powder being 0.4-0.5 wt% and the concentration of graphene being 0.1-0.2 wt%. Then, the mixture was spray-dried and calcined at 590-610℃ under vacuum for 20-40 min to obtain SiC@graphene composite powder.

5. A method for preparing an automotive aluminum alloy material as described in any one of claims 1-4, characterized in that, Includes the following steps: (1) Mix 82-83 parts of matrix alloy powder, 3-4 parts of Sc-Zr reinforcing powder, 0.5-1 parts of SiC@graphene composite powder, 1-2 parts of TiH2 foaming agent, 4-6 parts of hollow glass microspheres, and 7-8 parts of aluminum powder evenly, and perform cold isostatic pressing to obtain a green blank; (2) The green blank obtained in step (1) is placed at 590-610℃ and under vacuum for 1-3 hours. After cooling to room temperature, the surface area is scanned with a fiber laser with a wavelength of 1064 nm and sealed to obtain an aluminum alloy plate. (3) Place the aluminum alloy plate obtained in step (2) under vacuum for 1-2 hours to degas it, then place it under 465-470℃ and argon for 15-25 minutes, then raise the temperature to 480-485℃ and calcine for 10-20 minutes, then lower the temperature to 470-480℃ and calcine for 20-30 minutes, immediately take it out and place it in hot water to complete water quenching, and finally place it under 115-125℃ and argon for 24-48 hours to stabilize it. After cooling to room temperature, perform micro-arc oxidation on the surface to obtain the aluminum alloy material for automobiles.

6. The method for preparing automotive aluminum alloy material as described in claim 5, characterized in that, The pressure for cold isostatic pressing in step (1) is 200 MPa.

7. The method for preparing automotive aluminum alloy material as described in claim 5, characterized in that, The power of the fiber laser scanning in step (2) is 600-800 W, the scanning speed is 9-11 mm / s, and the spot diameter is 0.1-0.3 mm.

8. The method for preparing automotive aluminum alloy material as described in claim 5, characterized in that, The temperature of the hot water used for water quenching in step (3) is 68-72℃.

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