High-entropy alloy gradient reinforced secondary aluminum composite material and preparation method thereof

Abstract

The invention provides a high-entropy alloy gradient reinforced secondary aluminum composite material, the composite material takes secondary aluminum as a matrix, a reinforced phase of a gradient material is formed by a high-entropy alloy and a ceramic material, and the reinforced phase is of a three-layer structure and comprises a high-entropy alloy middle layer and a ceramic material and high-entropy alloy composite layer arranged on the two opposite sides of the middle layer; preferably, the high-entropy alloy is prepared from 15 to 25 parts of Mn, 15 to 20 parts of Mo, 15 to 20 parts of Cu, 15 to 20 parts of Be, 15 to 20 parts of Mg and 10 to 25 The high-entropy alloy serves as a gradient reinforcement phase, a continuous transition layer from high strength to high toughness is formed in a secondary aluminum matrix, the inherent defects of secondary aluminum are overcome, and the overall performance is improved through the strain hardening effect of a gradient structure.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum alloys, and in particular to a high-entropy alloy gradient-reinforced recycled aluminum composite material and a preparation method thereof. Background Art

[0002] With the advancement of the global circular economy, the importance of recycled aluminum as a green metal has become increasingly prominent. Recycled aluminum is made by recycling scrap aluminum through smelting, purification and other processes. Its production energy consumption is only 3%-5% of primary aluminum, and it is widely used in construction, transportation, electronics and other fields. However, recycled aluminum has problems such as complex composition, high content of impurities (such as Fe, Zn), and insufficient performance stability, which leads to its use in low-end die-casting aluminum alloys. It is difficult to meet the demand for high-strength and corrosion-resistant materials in high-end fields such as aerospace and new energy vehicles. For example, 70% of domestic recycled aluminum products are only used for ordinary die-castings, and the smelting process lacks online detection technology, and the alloying control accuracy is low, which further limits its performance improvement. In this context, the innovative design of high entropy alloys (HEAs) provides a new approach for breakthroughs in the performance of recycled aluminum. High entropy alloys are composed of five or more main elements (such as Al, Co, Cr, Fe, Ni), and have properties such as high entropy effect, lattice distortion effect and "cocktail" effect. They exhibit high strength (>1000MPa), high hardness (>400HV) and excellent corrosion resistance and thermal stability. For example, the yield strength of the AlCoCrFeNi system high entropy alloy can reach 2164MPa, and the comprehensive performance of the material is significantly improved through solid solution strengthening and fine grain strengthening mechanisms. The multi-component design of this type of alloy makes its interface wettability with the aluminum matrix better than that of traditional ceramic reinforcement phases, providing an ideal reinforcement phase choice for metal matrix composites. In recent years, gradient structure design has become an important strategy for strengthening and toughening materials. Studies have shown that by constructing compositional or microstructural gradients, a synergistic improvement in strength and toughness can be achieved within the material. For example, when cracks propagate in nano-micron gradient nickel materials, the coarse-grained region delays fracture through the passivation effect, while the nanocrystalline region provides high strength, ultimately allowing the fracture toughness to exceed 200 MPa. Currently, studies have verified the feasibility of high-entropy alloy reinforced aluminum-based composites. For example, the interface bonding strength of Al0.25Cu0.75FeNiCo particle-reinforced aluminum alloy is significantly better than that of traditional reinforcements, and as the high-entropy alloy content increases, the hardness and tensile strength of the composite material increase linearly. Further combined with additive manufacturing technology, a gradient distribution of high-entropy alloy reinforcement phases in recycled aluminum can be achieved, such as the TiN / CoCrFeNiMn composite prepared by selective laser melting (SLM), whose ultrafine grain structure increases the strength by more than 30%. Impurity elements such as Fe and Si, commonly found in recycled aluminum (e.g., Fe content exceeding 0.5% tends to form a brittle β-AlFeSi phase), can react uncontrollably with the multicomponent components of high-entropy alloys, leading to unstable precipitation of reinforcement phases or interfacial failure. For example, Fe can accumulate at the high-entropy alloy / aluminum interface, forming brittle intermetallic compounds (e.g., Al-Fe-Co phases), significantly reducing interfacial bonding strength. Furthermore, the compositional design of existing high-entropy alloys (e.g., AlCoCrFeNi) is often tailored to a pure aluminum matrix, whereas recycled aluminum has a complex composition (including Zn, Mn, etc.), necessitating the optimization of the ratios of the principal elements in the high-entropy alloy to prevent the formation of deleterious phases. Summary of the Invention

[0003] Technical problem to be solved: The purpose of the present invention is to provide a high-entropy alloy gradient-reinforced recycled aluminum composite material, which uses high-entropy alloy as the gradient-reinforced phase to form a continuous transition layer from high strength to high toughness in the recycled aluminum matrix, thereby overcoming the inherent defects of recycled aluminum and utilizing the strain hardening effect of the gradient structure to improve the overall performance.

[0004] Technical solution: A high-entropy alloy gradient-reinforced recycled aluminum composite material, which uses recycled aluminum as the matrix and high-entropy alloy and ceramic materials to form the reinforcement phase of the gradient material. The reinforcement phase has a three-layer structure, including a high-entropy alloy middle layer and ceramic material and high-entropy alloy composite layers arranged on opposite sides of the middle layer. Preferably, the high entropy alloy is Mn 15-25 Mo 15-20 Cu 15-20 Be 15-20 Mg 10-25 The reinforcing phase is a porous structure, and the porosity of the intermediate layer is less than that of the composite layer. The ceramic material is porous alumina, and the alumina contains Ce, and the content of Ce in the alumina ceramic is 1 to 3 wt%. Preferably, the porosity of the intermediate layer is 84.5-90.8%, and the porosity of the composite layer is 91.6-94.2%. The method for preparing the high entropy alloy gradient reinforced recycled aluminum composite material comprises the following steps: S1. The high entropy alloy powder components are prepared in proportion and mechanically alloyed by ball milling to mix uniformly. Then, a pore-forming agent and polyethylene glycol are added and ball milled to mix uniformly to obtain an intermediate layer raw material. S2. The high entropy alloy powder components are prepared in proportion and mechanically alloyed and ball-milled to mix uniformly. Then, porous alumina micro-nano ceramic powder, a pore-forming agent and polyethylene glycol are added and ball-milled to mix uniformly to obtain a composite layer raw material. S3. The composite material and the intermediate layer of raw materials are layered and fed. First, the composite material is added to both sides of the mold. After the core is removed, the intermediate layer of raw materials is added. The mold is cold-pressed and dried, and sintered to obtain a gradient structure reinforcement phase. S4. The gradient structure reinforcement phase is added to hydrochloric acid for chemical etching to obtain a reinforcement phase; S5. The recycled aluminum scrap and pure aluminum ingots are melted to obtain the following elements and their mass percentages: Si: 0.8-1.2%; Fe: 0.25-0.85%; Cu: 0.22-0.3%; Zn: 0.08-0.15%; Cr: 0.06-0.24%; the remainder is Al, and the remaining elements are considered impurities and their content is less than 0.1%, to obtain recycled aluminum liquid; S6. The recycled aluminum liquid is poured and pressure-infiltrated into the pores of the reinforcement phase by pressure infiltration. After demolding, the recycled aluminum liquid is transferred to a muffle furnace and cooled with the furnace at a certain temperature to obtain a high-entropy alloy gradient-reinforced recycled aluminum composite material. Preferably, in step S1, the mass ratio of the pore-forming agent, polyethylene glycol, and high-entropy alloy is 28-35:5-8:55-65, the pore-forming agent is ammonium bicarbonate, and the ammonium bicarbonate is composed of ammonium bicarbonate with a particle size range of 100-200 um and ammonium bicarbonate with a particle size range of 450-650 um in a mass ratio of 1:3-8. Preferably, in step S2, the mass ratio of the pore-forming agent, polyethylene glycol, high entropy alloy, and porous alumina micro-nano ceramic powder is 35-45:5-8:50-55:5-10, the pore-forming agent is ammonium bicarbonate, and the ammonium bicarbonate is composed of ammonium bicarbonate with a particle size range of 150-250 um and ammonium bicarbonate with a particle size range of 500-800 um in a mass ratio of 1:4-6. Preferably, the pressure of the cold pressing in step S3 is 5-10 MPa, and the sintering parameters are: keeping the temperature at 200-300° C. for 50-70 minutes, heating to 750-850° C. and keeping the temperature for 2.5-3.5 hours. Preferably, the concentration of hydrochloric acid in step S4 is 0.2-0.4 mol / L. Preferably, the pressurizing pressure in step S6 is 150-220 MPa, the holding time is 5-8 min, and the temperature is 550-600° C. Beneficial effects: The high entropy alloy gradient reinforced recycled aluminum composite material of the present invention has the following advantages: 1. In the present invention, high entropy alloy is used as the gradient enhancement phase, Mn reacts with Fe and Cr in recycled aluminum to form high melting point intermetallic compounds (such as Al(Fe,Mn)Si phase), refines the Fe-rich brittle phase, alleviates the negative impact of Fe on aluminum plasticity, Cu and Mg react with free Si to form Mg2Si and Al2Cu phases, and improves the aging hardening ability; at the same time, Cu diffuses into the aluminum matrix to form solid solution strengthening; Be reacts with oxygen / nitrogen impurities to form BeO or Be3N2, reducing the harm of impurities, and Be can improve the interface wettability of HEA; Mg and Al form β-Mg17Al12 strengthening phase and promote the bonding of alumina ceramic interface to form MgAl2O4 spinel; 2. Ce doped alumina in the present invention can replace Al 3+ It causes lattice distortion and improves the fracture toughness of alumina. 1-3wt% is the best. Excessive amount will form CeO2 to weaken the interface. At the same time, Ce reacts with O / N in recycled aluminum to form Ce2O3 or CeN, purifying the grain boundary and reducing interface pores. 3. In the porous structure design of the present invention, the composite layers are located on both sides of the middle layer. The high-porosity composite layer allows aluminum melt to penetrate into the pores, forming a mechanical interlock; the low-porosity HEA middle layer provides the main load-bearing capacity, and the porosity gradient distribution avoids stress concentration; at the same time, the high-porosity composite layer adsorbs low-melting-point impurities (such as Zn and Si), and the HEA middle layer captures high-melting-point impurities (Fe and Cr). The gradient pores serve as diffusion channels, promoting the diffusion of HEA elements (such as Mn and Mg) into the aluminum matrix, forming a gradient solid solution zone. DETAILED DESCRIPTION The present invention will be further described below in conjunction with examples, which are provided to explain the present invention and are not limited to the following examples: Example 1 A high entropy alloy gradient reinforced recycled aluminum composite material, the composite material is based on recycled aluminum, and the high entropy alloy and ceramic material constitute the reinforcement phase of the gradient material, the reinforcement phase is a three-layer structure, including a high entropy alloy middle layer and ceramic material and high entropy alloy composite layers arranged on opposite sides of the middle layer; wherein the high entropy alloy is Mn 25 Mo 20 Cu 20 Be 20 Mg 15The ceramic material is porous alumina, and the alumina contains Ce, and the content of Ce in the alumina ceramic is 1wt%. The preparation method of the high-entropy alloy gradient-reinforced recycled aluminum composite material comprises the following steps: S1. The powders of the components of the high-entropy alloy are prepared in proportion and mechanically alloyed by ball milling to mix uniformly. Then, ammonium bicarbonate and polyethylene glycol are added and ball milled to mix uniformly. The mass ratio of ammonium bicarbonate, polyethylene glycol, and high-entropy alloy is 28:5:55. The ammonium bicarbonate is composed of ammonium bicarbonate with a particle size range of 100 to 200 μm and ammonium bicarbonate with a particle size range of 450 to 650 μm in a mass ratio of 1:5 to obtain an intermediate layer raw material; S2. The powders of the components of the high-entropy alloy are prepared in proportion and mechanically alloyed by ball milling to mix them uniformly. Then, porous alumina micro-nano ceramic powder, ammonium bicarbonate and polyethylene glycol are added and mixed uniformly by ball milling to obtain a composite layer raw material. The mass ratio of ammonium bicarbonate, polyethylene glycol, high-entropy alloy and porous alumina micro-nano ceramic powder is 35:5:50:5, and the ammonium bicarbonate is composed of ammonium bicarbonate with a particle size range of 150 to 250 μm and ammonium bicarbonate with a particle size range of 500 to 800 μm in a mass ratio of 1:4. S3. The composite layer raw material and the intermediate layer raw material are layered and added. The composite layer raw material is first added to both sides of the mold. After the core is removed, the intermediate layer raw material is added. The mold is cold-pressed and dried. The cold-pressing pressure is 5 MPa. The gradient structure reinforcement phase is sintered. The sintering parameters are 70 min at 200 ° C and then heated to 750 ° C for 3.5 h. S4. The gradient structure enhancement phase was added to a concentration of 0.2 mol / L hydrochloric acid for chemical etching to obtain an enhancement phase; S5. The recycled aluminum scrap and pure aluminum ingots are melted to obtain the following elements and their mass percentages: Si: 0.8%; Fe: 0.25%; Cu: 0.3%; Zn: 0.08%; Cr: 0.24%; the balance being Al, and the remaining elements being considered impurities and having a content of less than 0.1%, to obtain recycled aluminum liquid; S6. The recycled aluminum liquid is poured and pressure-infiltrated into the pores of the reinforcement phase by pressure infiltration at a pressure of 150 MPa and a holding time of 5 min. After demolding, the recycled aluminum liquid is transferred to a muffle furnace and cooled with the furnace at a temperature of 600°C to obtain a high-entropy alloy gradient-reinforced recycled aluminum composite material. Example 2 A high entropy alloy gradient reinforced recycled aluminum composite material, the composite material is based on recycled aluminum, and the high entropy alloy and ceramic material constitute the reinforcement phase of the gradient material, the reinforcement phase is a three-layer structure, including a high entropy alloy middle layer and ceramic material and high entropy alloy composite layers arranged on opposite sides of the middle layer; wherein the high entropy alloy is Mn 20 Mo20 Cu 20 Be 20 Mg 20 The ceramic material is porous alumina, and the alumina contains Ce, and the content of Ce in the alumina ceramic is 3wt%. The preparation method of the high-entropy alloy gradient-reinforced recycled aluminum composite material comprises the following steps: S1. The powders of the components of the high-entropy alloy are prepared in proportion and mechanically alloyed by ball milling to mix uniformly. Then, ammonium bicarbonate and polyethylene glycol are added and ball milled to mix uniformly. The mass ratio of ammonium bicarbonate, polyethylene glycol, and high-entropy alloy is 35:8:65. The ammonium bicarbonate is composed of ammonium bicarbonate with a particle size range of 100 to 200 μm and ammonium bicarbonate with a particle size range of 450 to 650 μm in a mass ratio of 1:8 to obtain an intermediate layer raw material; S2. The powders of the components of the high-entropy alloy are prepared in proportion and mechanically alloyed by ball milling to mix them uniformly. Then, porous alumina micro-nano ceramic powder, ammonium bicarbonate and polyethylene glycol are added and mixed uniformly by ball milling to obtain a composite layer raw material. The mass ratio of ammonium bicarbonate, polyethylene glycol, high-entropy alloy and porous alumina micro-nano ceramic powder is 45:8:55:10, and the ammonium bicarbonate is composed of ammonium bicarbonate with a particle size range of 150 to 250 μm and ammonium bicarbonate with a particle size range of 500 to 800 μm in a mass ratio of 1:6. S3. The composite layer raw material and the intermediate layer raw material are layered and added. The composite layer raw material is first added to both sides of the mold. After the core is removed, the intermediate layer raw material is added. The mold is cold-pressed and dried. The cold-pressing pressure is 10 MPa. The gradient structure reinforcement phase is sintered. The sintering parameters are 300 ° C for 50 min, then heated to 850 ° C for 2.5 h. S4. The gradient structure enhancement phase was added to a concentration of 0.4 mol / L hydrochloric acid for chemical etching to obtain an enhancement phase; S5. The recycled aluminum scrap and pure aluminum ingots are melted to obtain the following elements and their mass percentages: Si: 1.2%; Fe: 0.65%; Cu: 0.22%; Zn: 0.15%; Cr: 0.06%; the remainder is Al, and the remaining elements are considered impurities and have a content of less than 0.1% to obtain recycled aluminum liquid; S6. The recycled aluminum liquid is poured and pressure-infiltrated into the pores of the reinforcement phase using pressure infiltration. The pressure is 220 MPa and the pressure holding time is 8 minutes. After demolding, the material is transferred to a muffle furnace and cooled at 550°C to obtain a high-entropy alloy gradient-reinforced recycled aluminum composite material. Example 3 A high entropy alloy gradient reinforced recycled aluminum composite material, the composite material is based on recycled aluminum, and the high entropy alloy and ceramic material constitute the reinforcement phase of the gradient material, the reinforcement phase is a three-layer structure, including a high entropy alloy middle layer and ceramic material and high entropy alloy composite layers arranged on opposite sides of the middle layer; wherein the high entropy alloy is Mn 15 Mo 20 Cu 20 Be 20 Mg 25 The ceramic material is porous alumina, and the alumina contains Ce, and the content of Ce in the alumina ceramic is 1.5wt%. The preparation method of the high-entropy alloy gradient-reinforced recycled aluminum composite material comprises the following steps: S1. The powders of the components of the high-entropy alloy are prepared in proportion and mechanically alloyed by ball milling to mix uniformly. Then, ammonium bicarbonate and polyethylene glycol are added and ball milled to mix uniformly. The mass ratio of ammonium bicarbonate, polyethylene glycol, and high-entropy alloy is 30:6:58. The ammonium bicarbonate is composed of ammonium bicarbonate with a particle size range of 100 to 200 μm and ammonium bicarbonate with a particle size range of 450 to 650 μm in a mass ratio of 1:6 to obtain an intermediate layer raw material; S2. The powders of each component of the high entropy alloy are prepared in proportion, and after mechanical alloying and ball milling, porous alumina micro-nano ceramic powder is added, ammonium bicarbonate and polyethylene glycol are ball milled and mixed evenly to obtain a composite layer raw material. The mass ratio of ammonium bicarbonate, polyethylene glycol, high entropy alloy and porous alumina micro-nano ceramic powder is 38:7:52:9, and the ammonium bicarbonate is composed of ammonium bicarbonate with a particle size range of 150 to 250 μm and ammonium bicarbonate with a particle size range of 500 to 800 μm in a mass ratio of 1:5.2; S3. The composite layer raw material and the intermediate layer raw material are added in layers, the composite layer raw material is first added to both sides of the mold, the intermediate layer raw material is added after the core is pulled out, and the mold is cold pressed and dried. The cold pressing pressure is 6 MPa, and the gradient structure reinforcement phase is sintered. The sintering parameters are keeping warm at 250°C for 65 minutes, heating to 820°C and keeping warm for 3 hours; S4. The gradient structure enhancement phase was added to a concentration of 0.25 mol / L hydrochloric acid for chemical etching to obtain an enhancement phase; S5. The recycled aluminum scrap and pure aluminum ingots are melted to obtain the following elements and their mass percentages: Si: 0.9%; Fe: 0.85%; Cu: 0.26%; Zn: 0.09%; Cr: 0.12%; the balance being Al, with the remaining elements considered impurities and having a content of less than 0.1%, to obtain recycled aluminum liquid; S6. The recycled aluminum liquid is poured and pressure-infiltrated into the pores of the reinforcement phase using pressure infiltration. The pressure is 180 MPa and the pressure holding time is 8 minutes. After demolding, the material is transferred to a muffle furnace and cooled at 560°C to obtain a high-entropy alloy gradient-reinforced recycled aluminum composite material. Example 4 A high entropy alloy gradient reinforced recycled aluminum composite material, the composite material is based on recycled aluminum, and the high entropy alloy and ceramic material constitute the reinforcement phase of the gradient material, the reinforcement phase is a three-layer structure, including a high entropy alloy middle layer and ceramic material and high entropy alloy composite layers arranged on opposite sides of the middle layer; wherein the high entropy alloy is Mn 15 Mo 20 Cu 20 Be 20 Mg 25 The ceramic material is porous alumina, and the alumina contains Ce, and the content of Ce in the alumina ceramic is 2.5wt%. The preparation method of the high-entropy alloy gradient-reinforced recycled aluminum composite material comprises the following steps: S1. The powders of the components of the high-entropy alloy are prepared in proportion and mechanically alloyed by ball milling to mix uniformly. Then, ammonium bicarbonate and polyethylene glycol are added and ball milled to mix uniformly. The mass ratio of ammonium bicarbonate, polyethylene glycol, and high-entropy alloy is 32:7:62. The ammonium bicarbonate is composed of ammonium bicarbonate with a particle size range of 100 to 200 μm and ammonium bicarbonate with a particle size range of 450 to 650 μm in a mass ratio of 1:7 to obtain an intermediate layer raw material; S2. The powders of each component of the high entropy alloy are prepared in proportion, and after mechanical alloying and ball milling, porous alumina micro-nano ceramic powder is added, ammonium bicarbonate and polyethylene glycol are ball milled and mixed evenly to obtain a composite layer raw material. The mass ratio of ammonium bicarbonate, polyethylene glycol, high entropy alloy and porous alumina micro-nano ceramic powder is 42:7:52:8, and the ammonium bicarbonate is composed of ammonium bicarbonate with a particle size range of 150 to 250 μm and ammonium bicarbonate with a particle size range of 500 to 800 μm in a mass ratio of 1:4.5; S3. The composite layer raw material and the intermediate layer raw material are added in layers, the composite layer raw material is first added to both sides of the mold, the intermediate layer raw material is added after the core is removed, and the mold is cold pressed and dried. The cold pressing pressure is 9 MPa, and the gradient structure reinforcement phase is sintered. The sintering parameters are keeping warm at 280°C for 55 minutes, heating to 780°C and keeping warm for 2.8 hours; S4. The gradient structure enhancement phase was added to a concentration of 0.35 mol / L hydrochloric acid for chemical etching to obtain an enhancement phase; S5. The recycled aluminum scrap and pure aluminum ingots are melted to obtain the following elements and their mass percentages: Si: 1%; Fe: 0.65%; Cu: 0.28%; Zn: 0.12%; Cr: 0.2%; the remainder is Al, and the remaining elements are considered impurities and have a content of less than 0.1%, to obtain recycled aluminum liquid; S6. The recycled aluminum liquid is poured and pressure-infiltrated into the pores of the reinforcement phase using pressure infiltration. The pressure is 200 MPa and the pressure holding time is 6 min. After demolding, the material is transferred to a muffle furnace and cooled with the furnace at 580°C to obtain a high-entropy alloy gradient-reinforced recycled aluminum composite material. Example 5 A high entropy alloy gradient reinforced recycled aluminum composite material, the composite material is based on recycled aluminum, and the high entropy alloy and ceramic material constitute the reinforcement phase of the gradient material, the reinforcement phase is a three-layer structure, including a high entropy alloy middle layer and ceramic material and high entropy alloy composite layers arranged on opposite sides of the middle layer; wherein the high entropy alloy is Mn 15 Mo 20 Cu 20 Be 20 Mg 25 The ceramic material is porous alumina, and the alumina contains Ce, and the content of Ce in the alumina ceramic is 2wt%. The preparation method of the high-entropy alloy gradient-reinforced recycled aluminum composite material comprises the following steps: S1. The powders of the components of the high-entropy alloy are prepared in proportion and mechanically alloyed by ball milling to mix uniformly. Then, ammonium bicarbonate and polyethylene glycol are added and ball milled to mix uniformly. The mass ratio of ammonium bicarbonate, polyethylene glycol, and high-entropy alloy is 33:6:62. The ammonium bicarbonate is composed of ammonium bicarbonate with a particle size range of 100 to 200 μm and ammonium bicarbonate with a particle size range of 450 to 650 μm in a mass ratio of 1:7 to obtain an intermediate layer raw material; S2. The powders of each component of the high entropy alloy are prepared in proportion, and after mechanical alloying and ball milling, porous alumina micro-nano ceramic powder is added, ammonium bicarbonate and polyethylene glycol are ball milled and mixed evenly to obtain a composite layer raw material. The mass ratio of ammonium bicarbonate, polyethylene glycol, high entropy alloy and porous alumina micro-nano ceramic powder is 44:7:55:8, and the ammonium bicarbonate is composed of ammonium bicarbonate with a particle size range of 150 to 250 μm and ammonium bicarbonate with a particle size range of 500 to 800 μm in a mass ratio of 1:5.5; S3. The composite layer raw material and the intermediate layer raw material are added in layers, the composite layer raw material is first added to both sides of the mold, the intermediate layer raw material is added after the core is pulled out, and the mold is cold pressed and dried. The cold pressing pressure is 8 MPa, and the gradient structure reinforcement phase is sintered. The sintering parameters are kept at 280°C for 60 minutes, and then heated to 800°C for 3 hours. S4. The gradient structure enhancement phase was added to a concentration of 0.25 mol / L hydrochloric acid for chemical etching to obtain an enhancement phase; S5. The recycled aluminum scrap and pure aluminum ingots are melted to obtain the following elements and their mass percentages: Si: 1%; Fe: 0.6%; Cu: 0.25%; Zn: 0.12%; Cr: 0.08%; the remainder is Al, and the remaining elements are considered impurities and have a content of less than 0.1%, to obtain recycled aluminum liquid; S6. The recycled aluminum liquid is poured and pressure-infiltrated into the pores of the reinforcement phase using pressure infiltration. The pressure is 180 MPa and the pressure holding time is 6 minutes. After demolding, the recycled aluminum liquid is transferred to a muffle furnace and cooled with the furnace at 600°C to obtain a high-entropy alloy gradient-reinforced recycled aluminum composite material. Comparative Example 1 The difference between Comparative Example 1 and Example 5 is that the components of the high entropy alloy are different. The components of the high entropy alloy in this comparative example are Mn 15 Mo 20 Cu 20 Ti 20 Mg 25 ; A high entropy alloy gradient reinforced recycled aluminum composite material, the composite material is based on recycled aluminum, and the high entropy alloy and ceramic material constitute the reinforcement phase of the gradient material, the reinforcement phase is a three-layer structure, including a high entropy alloy middle layer and ceramic material and high entropy alloy composite layers arranged on opposite sides of the middle layer; wherein the high entropy alloy is Mn 15 Mo 20 Cu 20 Ti 20 Mg 25 The ceramic material is porous alumina, and the alumina contains Ce, and the content of Ce in the alumina ceramic is 2wt%. The preparation method of the high-entropy alloy gradient-reinforced recycled aluminum composite material comprises the following steps: S1. The powders of the components of the high-entropy alloy are prepared in proportion and mechanically alloyed by ball milling to mix uniformly. Then, ammonium bicarbonate and polyethylene glycol are added and ball milled to mix uniformly. The mass ratio of ammonium bicarbonate, polyethylene glycol, and high-entropy alloy is 33:6:62. The ammonium bicarbonate is composed of ammonium bicarbonate with a particle size range of 100 to 200 μm and ammonium bicarbonate with a particle size range of 450 to 650 μm in a mass ratio of 1:7 to obtain an intermediate layer raw material; S2. The powders of each component of the high entropy alloy are prepared in proportion, and after mechanical alloying and ball milling, porous alumina micro-nano ceramic powder is added, ammonium bicarbonate and polyethylene glycol are ball milled and mixed evenly to obtain a composite layer raw material. The mass ratio of ammonium bicarbonate, polyethylene glycol, high entropy alloy and porous alumina micro-nano ceramic powder is 44:7:55:8, and the ammonium bicarbonate is composed of ammonium bicarbonate with a particle size range of 150 to 250 μm and ammonium bicarbonate with a particle size range of 500 to 800 μm in a mass ratio of 1:5.5; S3. The composite layer raw material and the intermediate layer raw material are added in layers, the composite layer raw material is first added to both sides of the mold, the intermediate layer raw material is added after the core is pulled out, and the mold is cold pressed and dried. The cold pressing pressure is 8 MPa, and the gradient structure reinforcement phase is sintered. The sintering parameters are kept at 280°C for 60 minutes, and then heated to 800°C for 3 hours. S4. The gradient structure enhancement phase was added to a concentration of 0.25 mol / L hydrochloric acid for chemical etching to obtain an enhancement phase; S5. The recycled aluminum scrap and pure aluminum ingots are melted to obtain the following elements and their mass percentages: Si: 1%; Fe: 0.6%; Cu: 0.25%; Zn: 0.12%; Cr: 0.08%; the remainder is Al, and the remaining elements are considered impurities and have a content of less than 0.1%, to obtain recycled aluminum liquid; S6. The recycled aluminum liquid is poured and pressure-infiltrated into the pores of the reinforcement phase using pressure infiltration. The pressure is 180 MPa and the pressure holding time is 6 minutes. After demolding, the recycled aluminum liquid is transferred to a muffle furnace and cooled with the furnace at 600°C to obtain a high-entropy alloy gradient-reinforced recycled aluminum composite material. Comparative Example 2 The difference between Comparative Example 2 and Example 5 is that the composite material has a non-gradient structure; A high entropy alloy gradient reinforced recycled aluminum composite material, the composite material has recycled aluminum as a matrix, high entropy alloy and ceramic material as reinforcement phase, wherein the high entropy alloy is Mn 15 Mo 20 Cu 20 Be 20 Mg 25 , the ceramic material is porous alumina, and the alumina contains Ce, and the content of Ce in the alumina ceramic is 2wt%; The method for preparing the high entropy alloy gradient reinforced recycled aluminum composite material comprises the following steps: S1. The powders of the components of the high-entropy alloy are prepared in proportion and mechanically alloyed by ball milling to mix them uniformly. Then, porous alumina micro-nano ceramic powder, ammonium bicarbonate and polyethylene glycol are added and mixed uniformly by ball milling to obtain a composite layer raw material. The mass ratio of ammonium bicarbonate, polyethylene glycol, high-entropy alloy and porous alumina micro-nano ceramic powder is 44:7:55:8, and the ammonium bicarbonate is composed of ammonium bicarbonate with a particle size range of 150 to 250 μm and ammonium bicarbonate with a particle size range of 500 to 800 μm in a mass ratio of 1:5.5. S2. The composite material was added to the mold, cold pressed and dried at a pressure of 8 MPa. The gradient structure reinforcement phase was sintered. The sintering parameters were 280°C for 60 min, then raised to 800°C for 3 h. S3. The reinforcing phase was added to a concentration of 0.25 mol / L hydrochloric acid for chemical etching to obtain a reinforcing phase; S4. The recycled aluminum scrap and pure aluminum ingots are melted to obtain the following elements and their mass percentages: Si: 1%; Fe: 0.6%; Cu: 0.25%; Zn: 0.12%; Cr: 0.08%; the remainder is Al, and the remaining elements are considered impurities and have a content of less than 0.1% to obtain recycled aluminum liquid; S5. The recycled aluminum liquid is poured and pressure-infiltrated into the pores of the reinforcement phase using pressure infiltration at a pressure of 180 MPa for a holding time of 6 min. After demolding, the recycled aluminum liquid is transferred to a muffle furnace and cooled at 600°C to obtain a high-entropy alloy gradient-reinforced recycled aluminum composite material. Comparative Example 3 The difference between Comparative Example 3 and Example 5 is that the particle size range of the selected pore-forming agent is different; A high entropy alloy gradient reinforced recycled aluminum composite material, the composite material is based on recycled aluminum, and the high entropy alloy and ceramic material constitute the reinforcement phase of the gradient material, the reinforcement phase is a three-layer structure, including a high entropy alloy middle layer and ceramic material and high entropy alloy composite layers arranged on opposite sides of the middle layer; wherein the high entropy alloy is Mn 15 Mo 20 Cu 20 Be 20 Mg 25 The ceramic material is porous alumina, and the alumina contains Ce, and the content of Ce in the alumina ceramic is 2wt%. The preparation method of the high-entropy alloy gradient-reinforced recycled aluminum composite material comprises the following steps: S1. The powders of the components of the high-entropy alloy are prepared in proportion and mechanically alloyed by ball milling to obtain a uniform mixture. Then, ammonium bicarbonate and polyethylene glycol are added and ball milled to obtain a uniform mixture. The mass ratio of ammonium bicarbonate, polyethylene glycol, and high-entropy alloy is 33:6:62. The particle size of the ammonium bicarbonate is in the range of 450 to 650 μm to obtain the intermediate layer raw material. S2. The powders of the components of the high-entropy alloy are prepared in proportion and mechanically alloyed by ball milling to mix them uniformly. Then, porous alumina micro-nano ceramic powder, ammonium bicarbonate, and polyethylene glycol are added and ball milled to mix uniformly to obtain a composite layer raw material. The mass ratio of ammonium bicarbonate, polyethylene glycol, high-entropy alloy, and porous alumina micro-nano ceramic powder is 44:7:55:8, and the ammonium bicarbonate particle size range is 500 to 800 μm. S3. The composite layer raw material and the intermediate layer raw material are layered and added. The composite layer raw material is first added to both sides of the mold. After the core is removed, the intermediate layer raw material is added. The mold is cold-pressed and dried. The cold-pressing pressure is 8 MPa. The gradient structure reinforcement phase is sintered. The sintering parameters are 280 ° C for 60 min, then heated to 800 ° C for 3 h. S4. The gradient structure enhancement phase was added to a concentration of 0.25 mol / L hydrochloric acid for chemical etching to obtain an enhancement phase; S5. The recycled aluminum scrap and pure aluminum ingots are melted to obtain the following elements and their mass percentages: Si: 1%; Fe: 0.6%; Cu: 0.25%; Zn: 0.12%; Cr: 0.08%; the remainder is Al, and the remaining elements are considered impurities and have a content of less than 0.1%, to obtain recycled aluminum liquid; S6. The recycled aluminum liquid is poured and pressure-infiltrated into the pores of the reinforcement phase using pressure infiltration. The pressure is 180 MPa and the pressure holding time is 6 minutes. After demolding, the recycled aluminum liquid is transferred to a muffle furnace and cooled with the furnace at 600°C to obtain a high-entropy alloy gradient-reinforced recycled aluminum composite material. Comparative Example 4 The difference between Comparative Example 4 and Example 5 is that the alumina does not contain Ce; A high entropy alloy gradient reinforced recycled aluminum composite material, the composite material is based on recycled aluminum, and the high entropy alloy and ceramic material constitute the reinforcement phase of the gradient material, the reinforcement phase is a three-layer structure, including a high entropy alloy middle layer and ceramic material and high entropy alloy composite layers arranged on opposite sides of the middle layer; wherein the high entropy alloy is Mn 15 Mo 20 Cu 20 Be 20 Mg 25 , the ceramic material is porous alumina; The method for preparing the high entropy alloy gradient reinforced recycled aluminum composite material comprises the following steps: S1. The powders of the components of the high-entropy alloy are prepared in proportion and mechanically alloyed by ball milling to mix uniformly. Then, ammonium bicarbonate and polyethylene glycol are added and ball milled to mix uniformly. The mass ratio of ammonium bicarbonate, polyethylene glycol, and high-entropy alloy is 33:6:62. The ammonium bicarbonate is composed of ammonium bicarbonate with a particle size range of 100 to 200 μm and ammonium bicarbonate with a particle size range of 450 to 650 μm in a mass ratio of 1:7 to obtain an intermediate layer raw material; S2. The powders of each component of the high entropy alloy are prepared in proportion, and after mechanical alloying and ball milling, porous alumina micro-nano ceramic powder is added, ammonium bicarbonate and polyethylene glycol are ball milled and mixed evenly to obtain a composite layer raw material. The mass ratio of ammonium bicarbonate, polyethylene glycol, high entropy alloy and porous alumina micro-nano ceramic powder is 44:7:55:8, and the ammonium bicarbonate is composed of ammonium bicarbonate with a particle size range of 150 to 250 μm and ammonium bicarbonate with a particle size range of 500 to 800 μm in a mass ratio of 1:5.5; S3. The composite layer raw material and the intermediate layer raw material are added in layers, the composite layer raw material is first added to both sides of the mold, the intermediate layer raw material is added after the core is pulled out, and the mold is cold pressed and dried. The cold pressing pressure is 8 MPa, and the gradient structure reinforcement phase is sintered. The sintering parameters are kept at 280°C for 60 minutes, and then heated to 800°C for 3 hours. S4. The gradient structure enhancement phase was added to a concentration of 0.25 mol / L hydrochloric acid for chemical etching to obtain an enhancement phase; S5. The recycled aluminum scrap and pure aluminum ingots are melted to obtain the following elements and their mass percentages: Si: 1%; Fe: 0.6%; Cu: 0.25%; Zn: 0.12%; Cr: 0.08%; the remainder is Al, and the remaining elements are considered impurities and have a content of less than 0.1%, to obtain recycled aluminum liquid; S6. The recycled aluminum liquid is poured and pressure-infiltrated into the pores of the reinforcement phase using pressure infiltration. The pressure is 180 MPa and the pressure holding time is 6 minutes. After demolding, the recycled aluminum liquid is transferred to a muffle furnace and cooled with the furnace at 600°C to obtain a high-entropy alloy gradient-reinforced recycled aluminum composite material. Comparative Example 5 The difference between Comparative Example 5 and Example 5 is that high entropy alloy is directly used for reinforcement without adding aluminum oxide; A high entropy alloy gradient reinforced recycled aluminum composite material, the composite material is based on recycled aluminum and a high entropy alloy as a reinforcement phase, the reinforcement phase is a three-layer structure, including a low-porosity high-entropy alloy middle layer and a high-porosity high-entropy alloy upper and lower layers arranged on opposite sides of the middle layer; wherein the high entropy alloy is Mn 15 Mo 20 Cu 20 Be 20 Mg 25 ; The method for preparing the high entropy alloy gradient reinforced recycled aluminum composite material comprises the following steps: S1. The powders of the components of the high-entropy alloy are prepared in proportion and mechanically alloyed by ball milling to mix uniformly. Then, ammonium bicarbonate and polyethylene glycol are added and ball milled to mix uniformly. The mass ratio of ammonium bicarbonate, polyethylene glycol, and high-entropy alloy is 33:6:62. The ammonium bicarbonate is composed of ammonium bicarbonate with a particle size range of 100 to 200 μm and ammonium bicarbonate with a particle size range of 450 to 650 μm in a mass ratio of 1:7 to obtain an intermediate layer raw material; S2. The powders of the components of the high-entropy alloy are prepared in proportion and mechanically alloyed by ball milling to mix them uniformly. Then, porous alumina micro-nano ceramic powder is added, ammonium bicarbonate and polyethylene glycol are ball milled and mixed uniformly to obtain upper and lower layer raw materials. The mass ratio of ammonium bicarbonate, polyethylene glycol and high-entropy alloy is 44:7:55, and the ammonium bicarbonate is composed of ammonium bicarbonate with a particle size range of 150 to 250 μm and ammonium bicarbonate with a particle size range of 500 to 800 μm in a mass ratio of 1:5.5. S3. The upper and lower layers of raw materials and the middle layer of raw materials are added layer by layer. The upper and lower layers of raw materials are first added to both sides of the mold. After the core is removed, the middle layer of raw materials is added. The mold is cold-pressed and dried. The cold-pressing pressure is 8 MPa. The gradient structure reinforcement phase is sintered. The sintering parameters are 280 ° C for 60 min, then heated to 800 ° C for 3 h. S4. The gradient structure enhancement phase was added to a concentration of 0.25 mol / L hydrochloric acid for chemical etching to obtain an enhancement phase; S5. The recycled aluminum scrap and pure aluminum ingots are melted to obtain the following elements and their mass percentages: Si: 1%; Fe: 0.6%; Cu: 0.25%; Zn: 0.12%; Cr: 0.08%; the remainder is Al, and the remaining elements are considered impurities and have a content of less than 0.1%, to obtain recycled aluminum liquid; S6. The recycled aluminum liquid is poured and pressure-infiltrated into the pores of the reinforcement phase using pressure infiltration. The pressure is 180 MPa and the pressure holding time is 6 minutes. After demolding, the recycled aluminum liquid is transferred to a muffle furnace and cooled with the furnace at 600°C to obtain a high-entropy alloy gradient-reinforced recycled aluminum composite material. Comparative Example 6 The difference between Comparative Example 6 and Example 5 is that the composite layer and the middle layer are swapped; A high entropy alloy gradient reinforced recycled aluminum composite material, the composite material is based on recycled aluminum, and the high entropy alloy and ceramic material constitute the reinforcement phase of the gradient material, the reinforcement phase is a three-layer structure, including a ceramic material and high entropy alloy composite layer and a high entropy alloy layer arranged on opposite sides of the composite layer; wherein the high entropy alloy is Mn 15 Mo 20 Cu 20Be 20 Mg 25 , the ceramic material is porous alumina, and the alumina contains Ce, and the content of Ce in the alumina ceramic is 2wt%; The method for preparing the high entropy alloy gradient reinforced recycled aluminum composite material comprises the following steps: S1. The powders of the components of the high-entropy alloy are prepared in proportion and mechanically alloyed by ball milling to mix uniformly. Then, ammonium bicarbonate and polyethylene glycol are added and ball milled to mix uniformly. The mass ratio of ammonium bicarbonate, polyethylene glycol, and high-entropy alloy is 33:6:62. The ammonium bicarbonate is composed of ammonium bicarbonate with a particle size range of 100 to 200 μm and ammonium bicarbonate with a particle size range of 450 to 650 μm in a mass ratio of 1:7 to obtain a high-entropy alloy layer raw material; S2. The powders of each component of the high entropy alloy are prepared in proportion, and after mechanical alloying and ball milling, porous alumina micro-nano ceramic powder is added, ammonium bicarbonate and polyethylene glycol are ball milled and mixed evenly to obtain a composite layer raw material. The mass ratio of ammonium bicarbonate, polyethylene glycol, high entropy alloy and porous alumina micro-nano ceramic powder is 44:7:55:8, and the ammonium bicarbonate is composed of ammonium bicarbonate with a particle size range of 150 to 250 μm and ammonium bicarbonate with a particle size range of 500 to 800 μm in a mass ratio of 1:5.5; S3. The composite layer raw material and the high entropy alloy layer raw material are added in layers, the high entropy alloy layer raw material is first added to both sides of the mold, the composite layer raw material is added after the core is removed, cold pressing and drying, the cold pressing pressure is 8 MPa, and the gradient structure reinforcement phase is sintered. The sintering parameters are keeping warm at 280°C for 60 minutes, heating to 800°C and keeping warm for 3 hours; S4. The gradient structure enhancement phase was added to a concentration of 0.25 mol / L hydrochloric acid for chemical etching to obtain an enhancement phase; S5. The recycled aluminum scrap and pure aluminum ingots are melted to obtain the following elements and their mass percentages: Si: 1%; Fe: 0.6%; Cu: 0.25%; Zn: 0.12%; Cr: 0.08%; the remainder is Al, and the remaining elements are considered impurities and have a content of less than 0.1%, to obtain recycled aluminum liquid; S6. The recycled aluminum liquid is poured and pressure-infiltrated into the pores of the reinforcement phase using pressure infiltration. The pressure is 180 MPa and the pressure holding time is 6 minutes. After demolding, the recycled aluminum liquid is transferred to a muffle furnace and cooled with the furnace at 600°C to obtain a high-entropy alloy gradient-reinforced recycled aluminum composite material. Table 1 shows the distribution of porosity in the examples and comparative examples. Each embodiment and comparative example was prepared into a standard specimen (50 mm * 70 mm * 120 mm), and a tensile test was performed using a universal testing machine. The tensile test method was carried out in accordance with the GB / T 228.1-2021 standard. The results are shown in Table 2. Table 2 shows the mechanical properties of the samples in the examples and comparative examples. Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A high entropy alloy gradient reinforced recycled aluminum composite material, characterized by: The composite material uses recycled aluminum as a matrix, and uses high entropy alloy and ceramic material to form a reinforcement phase of the gradient material. The reinforcement phase is a three-layer structure, including a high entropy alloy middle layer and ceramic material and high entropy alloy composite layers arranged on opposite sides of the middle layer.

2. The high entropy alloy gradient reinforced recycled aluminum composite material according to claim 1, characterized in that: The high entropy alloy is Mn 15-25 Mo 15-20 Cu 15-20 Be 15-20 Mg 10-25 The reinforcing phase is a porous structure, and the porosity of the intermediate layer is less than that of the composite layer. The ceramic material is porous alumina, and the alumina contains Ce, and the content of Ce in the alumina ceramic is 1 to 3 wt%.

3. The high entropy alloy gradient reinforced recycled aluminum composite material according to claim 2, characterized in that: The porosity of the intermediate layer is 84.5-90.8%, and the porosity of the composite layer is 91.6-94.2%.

4. The method for preparing a high entropy alloy gradient-enhanced recycled aluminum composite material according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1. The high entropy alloy powder components are prepared in proportion and mechanically alloyed by ball milling to mix uniformly. Then, a pore-forming agent and polyethylene glycol are added and ball milled to mix uniformly to obtain an intermediate layer raw material. S2. The high entropy alloy powder components are prepared in proportion and mechanically alloyed and ball-milled to mix uniformly. Then, porous alumina micro-nano ceramic powder, a pore-forming agent and polyethylene glycol are added and ball-milled to mix uniformly to obtain a composite layer raw material. S3. The composite material and the intermediate layer of raw materials are layered and fed. First, the composite material is added to both sides of the mold. After the core is removed, the intermediate layer of raw materials is added. The mold is cold-pressed and dried, and sintered to obtain a gradient structure reinforcement phase. S4. The gradient structure reinforcement phase is added to hydrochloric acid for chemical etching to obtain a reinforcement phase; S5. The recycled aluminum scrap and pure aluminum ingots are melted, and the types and mass percentages of the various elements meet the following requirements: Si: 0.8 to 1.2%; Fe: 0.25-0.85%; Cu: 0.22~0.3%; Zn: 0.08-0.15%; Cr: 0.06-0.24%; the balance is Al, and the remaining elements are considered impurities and their content is less than 0.1% to obtain recycled aluminum liquid; S6. The recycled aluminum liquid is poured and pressure-infiltrated into the pores of the reinforcement phase by pressure infiltration. After demolding, the recycled aluminum liquid is transferred to a muffle furnace and cooled with the furnace at a certain temperature to obtain a high-entropy alloy gradient-reinforced recycled aluminum composite material.

5. The method for preparing the high entropy alloy gradient reinforced recycled aluminum composite material according to claim 4, characterized in that: In step S1, the mass ratio of the pore-forming agent, polyethylene glycol, and high-entropy alloy is 28-35:5-8:55-65, the pore-forming agent is ammonium bicarbonate, and the ammonium bicarbonate is composed of ammonium bicarbonate with a particle size range of 100-200 μm and ammonium bicarbonate with a particle size range of 450-650 μm in a mass ratio of 1:3-8.

6. The method for preparing the high entropy alloy gradient reinforced recycled aluminum composite material according to claim 4, characterized in that: In step S2, the mass ratio of the pore-forming agent, polyethylene glycol, high entropy alloy, and porous alumina micro-nano ceramic powder is 35-45:5-8:50-55:5-10, the pore-forming agent is ammonium bicarbonate, and the ammonium bicarbonate is composed of ammonium bicarbonate with a particle size range of 150-250 μm and ammonium bicarbonate with a particle size range of 500-800 μm in a mass ratio of 1:4-6.

7. The method for preparing the high entropy alloy gradient reinforced recycled aluminum composite material according to claim 4, characterized in that: The pressure of the cold pressing in step S3 is 5-10 MPa, and the sintering parameters are: keeping the temperature at 200-300° C. for 50-70 minutes, heating to 750-850° C. and keeping the temperature for 2.5-3.5 hours.

8. The method for preparing a high entropy alloy gradient reinforced recycled aluminum composite material according to claim 4, characterized in that: The concentration of hydrochloric acid in step S4 is 0.2-0.4 mol / L.

9. The method for preparing a high entropy alloy gradient reinforced recycled aluminum composite material according to claim 4, characterized in that: The pressurizing pressure in step S6 is 150-220 MPa, the holding time is 5-8 minutes, and the temperature is 550-600° C.

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