Automotive lightweight high-strength aluminum alloy profile and preparation process thereof

Abstract

The invention discloses a lightweight high-strength aluminum alloy profile for vehicles and a preparation process thereof, and belongs to the technical field of aluminum alloys, the lightweight high-strength aluminum alloy profile for vehicles comprises basic components and enhanced components, the basic components comprise, by weight, 0.6%-1.2% of Mg, 0.7%-0.8% of Si, 0.3%-0.5% of Mn, 0.03%-0.05% of Cr and 0.3%-0.4% of Fe; the reinforcing component comprises 0.7%-2.1% of pretreated halloysite and 1%-5% of rare earth doped ceramic particles; less than or equal to 0.1% of other inevitable impurity elements and the balance of aluminum; the pretreated halloysite is halloysite subjected to dehydration treatment. The alpha-Al2O3 particles and the transition metal boride are introduced by adding the pretreated halloysite and in-situ generation of the rare earth doped ceramic particles, the mechanical property of the aluminum alloy profile is improved, the heat dissipation performance of the material is effectively improved, and the overall performance of the aluminum alloy profile is improved.

Description

Technical Field

[0001] This invention belongs to the field of aluminum alloy technology, specifically relating to a lightweight, high-strength aluminum alloy profile for automobiles and its preparation process. Background Technology

[0002] Aluminum alloys are alloys with aluminum as the base and a certain amount of other alloying elements added. They are one of the lightweight metal materials. In addition to the general properties of aluminum, aluminum alloys also have some specific alloy characteristics due to the different types and amounts of alloying elements added.

[0003] Aluminum alloys are among the most widely used non-ferrous structural materials, favored in aerospace, automotive, machinery manufacturing, shipbuilding, and chemical industries. In the automotive manufacturing industry, reducing vehicle weight is crucial for energy conservation and emission reduction, as the vehicle body accounts for approximately 40% of the total vehicle weight, making its lightweighting essential. By optimizing design and using new materials such as aluminum alloys to reduce vehicle weight, a comprehensive goal of weight reduction, energy saving, environmental protection, and safety can be achieved. Aluminum alloys, with their low density (approximately one-third that of steel), high strength-to-weight ratio, good recyclability, aesthetic design, energy saving, heat dissipation, corrosion resistance, and fatigue resistance, have become the preferred material for automotive lightweighting. To meet the lightweighting requirements of automotive components while ensuring mechanical performance, existing lightweighting methods mainly fall into two categories: one is optimizing the structure of automotive parts, but this is limited by factors such as design in actual production; the other is optimizing the material itself, improving the internal density of the aluminum alloy to enhance its performance.

[0004] Compared to traditional aluminum alloys, particle-reinforced aluminum matrix composites refer to composites in which particles are added during the solidification process of the aluminum alloy. These particles act as nucleation centers for heterogeneous formation, promoting the formation of crystal nuclei while hindering the free growth of grains, thus refining the grains. Refined grains increase the grain boundary area, reducing porosity and defects between grain boundaries, resulting in a denser microstructure and superior mechanical properties. However, when the added particles are small, especially nanoscale particles, their large specific surface area and high surface energy make them more prone to agglomeration and difficult to uniformly disperse in the matrix. This limits the addition of submicron or nanoscale reinforcing particles, hindering further improvement in the composite's performance. Furthermore, the low interfacial bonding strength between the added particles and the aluminum matrix easily forms weak interfaces, leading to stress concentration under stress. This causes cracks to appear and propagate rapidly, reducing the composite's mechanical properties and making it highly susceptible to failure. Summary of the Invention

[0005] The purpose of this invention is to provide a lightweight, high-strength aluminum alloy profile for automobiles and its manufacturing process, so as to solve the problem of insufficient mechanical properties of aluminum alloy profiles.

[0006] The objective of this invention can be achieved through the following technical solutions: A lightweight, high-strength aluminum alloy profile for automotive applications includes a base component and a reinforcing component. The base component, by weight percentage, comprises Mg: 0.6%–1.2%, Si: 0.7%–0.8%, Mn: 0.3%–0.5%, Cr: 0.03%–0.05%, and Fe: 0.3%–0.4%. The reinforcing component comprises 0.7%–2.1% pretreated halloysite, 1%–5% rare earth-doped ceramic particles, other unavoidable impurity elements ≤0.1%, and the balance aluminum. The pretreated halloysite is dehydrated halloysite.

[0007] Alumina itself possesses high hardness, good wear resistance, and thermal stability, and is commonly used as a reinforcing material in aluminum alloy preparation. Halloysite contains approximately 30%–50% alumina. In this invention, dehydrated halloysite reacts with aluminum in situ to generate α-Al₂O₃, which significantly improves the mechanical properties of the alloy and the wear resistance of its surface. The α-Al₂O₃ particles generated in situ in this invention can serve as heterogeneous nucleation sites for α-Al grains, refining the grains and exhibiting stronger interfacial bonding with the aluminum matrix. Furthermore, they are less prone to agglomeration, avoiding problems such as poor dispersion and porosity defects associated with added particles.

[0008] Furthermore, the pretreated halloysite is prepared through the following steps: Halloysite was calcined at 400-500℃ for 3-4 hours to obtain pretreated halloysite. Halloysite is a natural nanotube silicate mineral (chemical formula Al2Si2O5(OH)4·nH2O), whose composition is closer to pure aluminosilicate with low impurity content. Its alternating coiled structure of silicon-oxygen tetrahedral layers (SiO4) and aluminum-oxygen octahedral layers (AlO6) tends to directly generate α-Al2O3, reducing the release of Si. The tubular structure can still maintain good crystal stability after dehydration (400-500℃), reducing the formation of amorphous substances and thus reducing the risk of random reactions with other elements in the melt, resulting in fewer by-products.

[0009] Furthermore, the reinforcing components include 0.7% to 2.1% pretreated halloysite and 1% to 5% rare earth-doped ceramic particles.

[0010] Furthermore, by weight percentage, the rare earth-doped ceramic particles comprise 1% to 5% rare earth elements, 45% to 50% transition metal borides, and the balance aluminum.

[0011] Furthermore, the transition metal boride is TiB2 and / or ZrB2.

[0012] Furthermore, the rare earth-doped ceramic particles are prepared through the following steps: Pure aluminum is heated to 800-850℃ to melt, and then aluminum rare earth alloy is added. After slag removal, potassium fluorotitanate, potassium fluorozirconate, and potassium borofluorate are added. The mixture is stirred for 15-20 minutes, kept at the temperature for 30-40 minutes, cooled to 700-720℃, and refined by purging with nitrogen. The slag is then removed, and the mixture is poured into a preheated mold. The molar ratio of potassium fluorotitanate, potassium fluorozirconate, and potassium borofluorate is 0-1:0-1:2-4.

[0013] Transition metal borides are compounds formed by the chemical bonding of transition metals and boron. They possess high hardness and high-temperature resistance. The transition metal borides in this invention are TiB2 and / or ZrB2, exhibiting good stability and high-temperature strength, which can improve the strength of aluminum alloy substrates. Compared to directly adding TiB2 and / or ZrB2 particles, this invention uses aluminum and aluminum rare earth alloys as the matrix material to generate transition metal borides in situ. This reduces the agglomeration of transition metal borides, lowers the interfacial energy between transition metal borides and the aluminum alloy matrix, and allows them to act as heterogeneous nucleation sites, promoting solidification nucleation of the aluminum alloy melt, refining the as-cast grain structure of the aluminum alloy, and indirectly improving the strength and plasticity of the aluminum alloy material.

[0014] The introduction of rare earth elements into rare earth-doped ceramic particles can further refine the particle size of TiB2 and / or ZrB2 particles. By incorporating TiB2 and / or ZrB2 particles into aluminum alloy base materials in the form of rare earth-doped ceramic particles, the fluidity of the aluminum melt is utilized to improve the uniform suspension and dispersion of the rare earth-doped ceramic particles in the base material. This fully leverages the nanoscale effect, strong interfacial bonding, and fine grain structure of TiB2 and / or ZrB2 particles, significantly improving the modulus and strength of aluminum alloy profiles with almost no increase in density. Furthermore, the fine and uniformly distributed particles can effectively reduce stress concentration, improving the toughness and fatigue resistance of the material.

[0015] When two types of particles (TiB2 and ZrB2 particles) are added simultaneously to the aluminum alloy matrix, they work together to bear the load and exert their respective reinforcing effects, which can further improve the mechanical properties of the aluminum alloy on the basis of adding them individually.

[0016] Rare earth doped ceramic particles are added as a reinforcing component, which also introduces rare earth elements. Rare earth elements can react with elements such as Si in the alloy to form rod-shaped and granular AlSiY phases or AlSiCe phases, reducing the content of dissolved silicon atoms (introduced by halloysite) in the alloy and reducing the negative impact of excessive silicon on mechanical properties.

[0017] Furthermore, the aluminum rare earth alloy is one of Al-20Ce master alloy and Al-20Y master alloy. Rare earth Ce and rare earth Y are added in the form of Al-20Ce master alloy and Al-20Y master alloy, respectively.

[0018] A manufacturing process for a lightweight, high-strength aluminum alloy profile for automotive applications includes the following steps: After drying the basic raw materials, they are added to a melting furnace for melting at a temperature of 740-750℃ and held for 35-50 minutes to obtain aluminum alloy melt. Hexachloroethane, accounting for 0.3% to 0.4% of the melt mass, is added as a refining agent for refining, slag removal, and exhaust. Pretreated halloysite is slowly added to the aluminum alloy melt, the temperature is raised to 880-900℃, stirred for 15-20 min, and then held at that temperature for 30-40 min. Then the temperature is lowered to 740-750℃, rare earth-doped ceramic particles are added, stirred for 15-20 min, and then held at that temperature for 30-40 min. Subsequently, 0.3% to 0.4% of hexachloroethane by mass of the melt is added as a refining agent for refining. After slag removal and degassing, the material is allowed to stand and then poured into a mold preheated at 250-300℃ for 30-40 min. The obtained material is then heat-treated to obtain lightweight high-strength aluminum alloy profiles for automobiles.

[0019] Furthermore, the heat treatment includes first holding at 500-540℃ for 4-5 hours, then quenching in water at 60-100℃, and finally aging at 160-170℃ for 4-6 hours, followed by air cooling.

[0020] The beneficial effects of this invention are: This invention provides a lightweight, high-strength aluminum alloy profile for automobiles. By adding pretreated halloysite and rare earth-doped ceramic particles, the mechanical properties of the aluminum alloy profile are improved, and the heat dissipation performance of the material is effectively enhanced, thereby improving the overall performance of the aluminum alloy profile.

[0021] To avoid the problems of agglomeration and difficulty in uniform dispersion of nanoscale particles caused by direct addition, this invention uses halloysite as a raw material. The in-situ generated α-Al₂O₃ particles serve as heterogeneous nucleation sites for α-Al grains, refining the grain structure and providing stronger interfacial bonding with the aluminum matrix. This also reduces the likelihood of agglomeration, avoiding the problems of poor dispersion and porosity defects associated with added particles. Furthermore, this invention uses aluminum and aluminum-rare-earth alloys as the matrix material to generate transition metal borides in situ. This reduces the agglomeration of transition metal borides, lowers the interfacial energy between transition metal borides and the aluminum alloy matrix, and allows them to act as heterogeneous nucleation sites, promoting the solidification and nucleation of the aluminum alloy melt, refining the as-cast grain structure of the aluminum alloy, and indirectly improving the strength and plasticity of the aluminum alloy material. The combined effect of pretreated halloysite and rare-earth-doped ceramic particles further enhances the performance of the aluminum alloy profiles. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] Obviously, the following description is merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios without any inventive effort. Furthermore, it is understood that although the effort involved in such development may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, any changes to design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as insufficient disclosure of the content of this application.

[0024] However, there may be instances where unnecessary detailed descriptions are omitted. For example, detailed descriptions of well-known matters or repetitive descriptions of essentially the same structure may be omitted. This is to avoid making the following description unnecessarily lengthy and to facilitate understanding by those skilled in the art. Furthermore, the following description is provided to enable those skilled in the art to fully understand this application and is not intended to limit the subject matter of the claims.

[0025] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions, and all technical features and optional technical features of this application can be combined to form new technical solutions.

[0026] The following is a detailed description of a lightweight, high-strength aluminum alloy profile for automobiles and its manufacturing process, based on embodiments of this application. The raw materials used in the basic components of the embodiments and comparative examples of this application include industrial pure aluminum with a purity of 99.7%, magnesium with a purity of 99.99%, Al-Si master alloy, Al-Mn master alloy, aluminum-type chromium agent, and Al-Fe master alloy.

[0027] The following is a detailed description with reference to specific examples.

[0028] Example 1

[0029] This embodiment provides a lightweight high-strength aluminum alloy profile for automobiles, comprising a base component and a reinforcing component. The base component, by weight percentage, comprises Mg: 0.8%, Si: 0.7%, Mn: 0.4%, Cr: 0.04%, and Fe: 0.3%. The reinforcing component comprises 0.7% pretreated halloysite, 1% rare earth-doped ceramic particles, other unavoidable impurity elements ≤0.1%, and the balance being aluminum.

[0030] The pretreated halloysite is halloysite that has undergone dehydration treatment; the pretreated halloysite is prepared by the following steps: calcining halloysite at 400℃ for 4 hours to obtain pretreated halloysite.

[0031] The rare earth-doped ceramic particles comprise 5% rare earth elements, 50% transition metal borides, and the balance aluminum. The rare earth-doped ceramic particles are prepared through the following steps: Pure aluminum is heated to 850℃ to melt, and then an aluminum-rare earth alloy is added. After slag removal, potassium fluorotitanate and potassium borofluoroate are added, stirred for 20 minutes, held at that temperature for 40 minutes, cooled to 700℃, and refined by purging with nitrogen. The slag is then removed, and the mixture is poured into a preheated mold. The molar ratio of potassium fluorotitanate to potassium borofluoroate is 1:2. The aluminum-rare earth alloy is an Al-20Y master alloy.

[0032] The manufacturing process of this lightweight, high-strength aluminum alloy profile for automobiles includes the following steps: After drying the basic raw materials, they are added to a melting furnace for melting at a temperature of 750℃ and held for 35 minutes to obtain aluminum alloy melt. Hexachloroethane, accounting for 0.3% of the melt mass, is added as a refining agent for refining, slag removal, and exhaust. Pretreated halloysite was slowly added to the aluminum alloy melt, the temperature was raised to 880℃, stirred for 20 min, and then held at that temperature for 30 min. Then the temperature was lowered to 750℃, rare earth-doped ceramic particles were added, stirred for 20 min, and then held at that temperature for 30 min. Subsequently, hexachloroethane (0.3% by mass of the melt) was added as a refining agent for refining. After slag removal and degassing, the material was allowed to stand and then poured into a mold preheated at 250℃ for 40 min. The obtained material was then subjected to heat treatment: first, it was held at 500℃ for 4 h, then quenched in water at 100℃, and finally aged at 170℃ for 5 h and air-cooled to obtain a lightweight high-strength aluminum alloy profile for automotive applications.

[0033] Example 2

[0034] This embodiment provides a lightweight high-strength aluminum alloy profile for automobiles, comprising a base component and a reinforcing component. The base component, by weight percentage, comprises Mg: 0.8%, Si: 0.7%, Mn: 0.4%, Cr: 0.04%, and Fe: 0.3%. The reinforcing component comprises 1.4% pretreated halloysite, 3% rare earth-doped ceramic particles, other unavoidable impurity elements ≤0.1%, and the balance being aluminum.

[0035] The pretreated halloysite is halloysite that has undergone dehydration treatment; the pretreated halloysite is prepared by the following steps: calcining halloysite at 400℃ for 4 hours to obtain pretreated halloysite.

[0036] The rare earth-doped ceramic particles contain 5% rare earth elements, 50% transition metal borides, and the balance aluminum.

[0037] The remaining raw materials and preparation process are the same as in Example 1.

[0038] Example 3

[0039] This embodiment provides a lightweight high-strength aluminum alloy profile for automobiles, comprising a base component and a reinforcing component. The base component, by weight percentage, comprises Mg: 0.8%, Si: 0.7%, Mn: 0.4%, Cr: 0.04%, and Fe: 0.3%. The reinforcing component comprises 2.1% pretreated halloysite, 5% rare earth-doped ceramic particles, other unavoidable impurity elements ≤0.1%, and the balance being aluminum.

[0040] The pretreated halloysite is halloysite that has undergone dehydration treatment; the pretreated halloysite is prepared by the following steps: calcining halloysite at 400℃ for 4 hours to obtain pretreated halloysite.

[0041] The rare earth-doped ceramic particles contain 5% rare earth elements, 50% transition metal borides, and the balance aluminum.

[0042] The remaining raw materials and preparation process are the same as in Example 1.

[0043] Example 4

[0044] This embodiment provides a lightweight high-strength aluminum alloy profile for automobiles. The difference between this embodiment and Embodiment 1 is that the pretreated halloysite is halloysite that has undergone dehydration treatment. The pretreated halloysite is prepared by the following steps: calcining halloysite at 500°C for 3 hours to obtain pretreated halloysite.

[0045] The remaining raw materials and preparation process are the same as in Example 1.

[0046] Example 5

[0047] This embodiment provides a lightweight, high-strength aluminum alloy profile for automobiles. The difference between this embodiment and Embodiment 1 is that the preparation process of the rare earth-doped ceramic particles is different, while the other raw materials and preparation process remain the same as in Embodiment 1. The rare earth-doped ceramic particles are prepared through the following steps: Pure aluminum is heated to 850℃ to melt, and then an aluminum-rare earth alloy is added. After slag removal, potassium fluorotitanate and potassium borofluoroate are added, stirred for 20 minutes, held at that temperature for 40 minutes, cooled to 700℃, and refined by purging with nitrogen. The slag is then removed, and the mixture is poured into a preheated mold. The molar ratio of potassium fluorotitanate to potassium borofluoroate is 1:2. The aluminum-rare earth alloy is an Al-20Ce master alloy.

[0048] Example 6

[0049] This embodiment provides a lightweight, high-strength aluminum alloy profile for automobiles. The difference between this embodiment and Embodiment 1 is that the preparation process of the rare earth-doped ceramic particles is different, while the other raw materials and preparation process remain the same as in Embodiment 1. The rare earth-doped ceramic particles are prepared through the following steps: Pure aluminum is heated to 850℃ to melt, and then an aluminum-rare earth alloy is added. After slag removal, potassium fluorotitanate, potassium fluorozirconate, and potassium borofluorate are added. The mixture is stirred for 20 minutes, held at that temperature for 40 minutes, cooled to 700℃, and refined by purging with nitrogen. The slag is then removed, and the mixture is poured into a preheated mold. The molar ratio of potassium fluorotitanate, potassium fluorozirconate, and potassium borofluorate is 1:1:4. The aluminum-rare earth alloy is an Al-20Y master alloy.

[0050] Example 7

[0051] This embodiment provides a lightweight, high-strength aluminum alloy profile for automobiles. The difference between this embodiment and Embodiment 2 is that the preparation process of the rare earth-doped ceramic particles is different, while the other raw materials and preparation process remain the same as in Embodiment 2. The rare earth-doped ceramic particles are prepared through the following steps: Pure aluminum is heated to 850℃ to melt, and then an aluminum-rare earth alloy is added. After slag removal, potassium fluorotitanate, potassium fluorozirconate, and potassium borofluorate are added. The mixture is stirred for 20 minutes, held at that temperature for 40 minutes, cooled to 700℃, and refined by purging with nitrogen. The slag is then removed, and the mixture is poured into a preheated mold. The molar ratio of potassium fluorotitanate, potassium fluorozirconate, and potassium borofluorate is 1:1:4. The aluminum-rare earth alloy is an Al-20Y master alloy.

[0052] Example 8

[0053] This embodiment provides a lightweight, high-strength aluminum alloy profile for automobiles. The difference between this embodiment and Embodiment 2 is that the preparation process of the rare earth-doped ceramic particles is different, while the other raw materials and preparation process remain the same as in Embodiment 2. The rare earth-doped ceramic particles are prepared through the following steps: Pure aluminum is heated to 850℃ to melt, and then an aluminum-rare earth alloy is added. After slag removal, potassium fluorotitanate, potassium fluorozirconate, and potassium borofluorate are added. The mixture is stirred for 20 minutes, held at that temperature for 40 minutes, cooled to 700℃, and refined by purging with nitrogen. The slag is then removed, and the mixture is poured into a preheated mold. The molar ratio of potassium fluorotitanate, potassium fluorozirconate, and potassium borofluorate is 1:1:4. The aluminum-rare earth alloy is an Al-20Ce master alloy.

[0054] Comparative Example 1

[0055] Compared to Example 1, this comparative example replaced 0.7% of the pretreated halloysite with 0.3% of alumina nanoparticles with a particle size of 30-60 nm. The remaining raw materials and preparation process remained the same as in Example 1.

[0056] Comparative Example 2

[0057] Compared to Example 1, this comparative example replaced 0.7% of the pretreated halloysite with 0.7% of alumina nanoparticles with a particle size of 30-60 nm. The remaining raw materials and preparation process remained the same as in Example 1.

[0058] Comparative Example 3

[0059] Compared to Example 1, this comparative example does not involve the addition of aluminum-rare-earth alloys during the preparation of rare-earth-doped ceramic particles. The specific steps are as follows: Pure aluminum is heated to 850°C to melt, then potassium fluorotitanate and potassium borofluoroate are added. After stirring for 20 minutes, the mixture is held at this temperature for 40 minutes, cooled to 700°C, and refined by purging with nitrogen. The slag is then removed, and the molten material is poured into a preheated mold. The molar ratio of potassium fluorotitanate to potassium borofluoroate is 1:2. The prepared sample contains 50% transition metal borides and the balance aluminum. The remaining raw materials and preparation process are the same as in Example 1.

[0060] Comparative Example 4

[0061] Compared to Example 1, this comparative example replaced 0.7% of pretreated halloysite with 0.7% alumina nanoparticles, and no aluminum-rare earth alloy was added during the preparation of rare earth-doped ceramic particles. The specific steps are as follows: Pure aluminum was heated to 850°C to melt, and potassium fluorotitanate and potassium borofluoroate were added. After stirring for 20 minutes, the mixture was kept at this temperature for 40 minutes, cooled to 700°C, and refined by purging with nitrogen. The slag was then removed, and the mixture was poured into a preheated mold. The molar ratio of potassium fluorotitanate to potassium borofluoroate was 1:2. The prepared sample contained 50% transition metal borides and the balance aluminum. The remaining raw materials and preparation process were the same as in Example 1.

[0062] The alloy samples prepared in Examples 1-8 and Comparative Examples 1-4 were subjected to performance tests, including stress corrosion resistance and thermal conductivity.

[0063] Stress corrosion test: Stress corrosion cracking at 1×10 -6 s -1 Slow strain rate tests were conducted on a slow tensile testing machine at a strain rate of [value missing], with tests performed in air and in a 3.5 wt% sodium chloride solution. The tests were conducted according to standard GB / T15970.7-2017. The results are shown in Table 1. Table 1

[0064] Based on the results in Table 1 and in conjunction with Examples 1-3, increasing the proportion of pretreated halloysite and rare earth-doped ceramic particles can refine the grains and improve the mechanical properties of the material. The in-situ generated α-Al2O3 particles and transition metal borides can serve as heterogeneous nucleation cores, avoiding problems such as poor dispersion and porosity defects of the added particles, and improving the material's resistance to stress corrosion.

[0065] According to the records, in Examples 6-8, the two types of particles (TiB2 and ZrB2 particles) were added simultaneously to the aluminum alloy matrix, working together to bear the load and exert their respective reinforcing effects, which further improved the mechanical properties of the aluminum alloy on the basis of adding them individually. In Examples 8 and 5, the type of rare earth doping was changed. Rare earth doped ceramic particles were added as a reinforcing component, and rare earth elements were also introduced. Rare earth elements can react with elements such as Si in the alloy to form rod-shaped and granular AlSiY phases or AlSiCe phases, reducing the content of silicon atoms dissolved in the alloy and reducing the negative impact of excessive silicon on mechanical properties. Among them, Ce can inhibit the nucleation and growth of primary phases, and Y can improve the morphology of β-AlFeSi in the aluminum alloy, reduce the cutting effect on the matrix, and improve the tensile properties of the material. Therefore, the material with added rare earth Y in the examples has a better improvement effect.

[0066] Compared with Example 1, the direct addition of nano-alumina in Comparative Examples 1 and 2 resulted in poor dispersibility and porosity defects, leading to poor stress corrosion resistance of the materials. In Comparative Example 3, no rare earth metals were introduced, which failed to fully utilize the nanoscale effect of alumina or transition metal borides, thus affecting the mechanical properties of the materials.

[0067] According to Table 1, the increase in the amount of pretreated halloysite in Examples 1-3 has a negative impact on the improvement of thermal conductivity. The increase in the amount of pretreated halloysite and rare earth doped ceramic particles causes the thermal conductivity to show a trend of first increasing and then decreasing. A comparison between Example 1 and Comparative Examples 1-4 shows that the introduction of rare earth elements can improve the thermal conductivity of the material. According to the results, Example 7 has the best thermal conductivity.

[0068] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0069] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A lightweight, high-strength aluminum alloy profile for automotive applications, characterized in that, It includes a base component and a reinforcing component. The base component, by weight percentage, includes... Mg: 0.6%–1.2%, Si: 0.7%–0.8%, Mn: 0.3%–0.5%, Cr: 0.03%–0.05%, Fe: 0.3%–0.4%; the reinforcing components include 0.7%–2.1% pretreated halloysite and 1%–5% rare earth-doped ceramic particles; Other unavoidable impurity elements ≤0.1% and balance aluminum; the pretreated halloysite is halloysite that has undergone dehydration treatment.

2. The lightweight high-strength aluminum alloy profile for automobiles according to claim 1, characterized in that, The pretreated halloysite is prepared through the following steps: Halloysite was calcined at 400-500℃ for 3-4 hours to obtain pretreated halloysite.

3. The lightweight high-strength aluminum alloy profile for automobiles according to claim 1, characterized in that, The reinforcing components include 1.4% pretreated halloysite and 3% rare earth-doped ceramic particles.

4. The lightweight high-strength aluminum alloy profile for automobiles according to claim 1, characterized in that, The rare earth-doped ceramic particles comprise 1% to 5% rare earth elements, 45% to 50% transition metal borides, and the balance aluminum by weight percentage.

5. A lightweight, high-strength aluminum alloy profile for automobiles according to claim 4, characterized in that, The transition metal borides are TiB2 and / or ZrB2.

6. The lightweight high-strength aluminum alloy profile for automobiles according to claim 1, characterized in that, The rare earth-doped ceramic particles are prepared through the following steps: Pure aluminum is heated to 800-850℃ to melt, and then aluminum rare earth alloy is added. After removing the slag, potassium fluorotitanate, potassium fluorozirconate and potassium borofluoride are added. After stirring for 15-20 minutes, the mixture is kept at the same temperature for 30-40 minutes. The temperature is then lowered to 700-720℃, and nitrogen is introduced for refining. Finally, the slag is removed, and the mixture is poured into a preheated mold.

7. A lightweight, high-strength aluminum alloy profile for automobiles according to claim 6, characterized in that, The molar ratio of potassium fluorotitanate, potassium fluorozirconate, and potassium borofluoride is 0-1:0-1:2-4.

8. A lightweight, high-strength aluminum alloy profile for automobiles according to claim 6, characterized in that, Aluminum rare earth alloys are one of Al-20Ce master alloys and Al-20Y master alloys.

9. A manufacturing process for a lightweight, high-strength aluminum alloy profile for automobiles, used to manufacture the lightweight, high-strength aluminum alloy profile for automobiles as described in any one of claims 1-8, characterized in that, Includes the following steps: After drying the basic raw materials, they are added to a melting furnace for melting at a temperature of 740-750℃ and held for 35-50 minutes to obtain aluminum alloy melt. Hexachloroethane, accounting for 0.3% to 0.4% of the melt mass, is added as a refining agent for refining, slag removal, and exhaust. Pretreated halloysite is slowly added to the aluminum alloy melt, the temperature is raised to 880-900℃, stirred for 15-20 min, and then held at that temperature for 30-40 min. Then the temperature is lowered to 740-750℃, rare earth-doped ceramic particles are added, stirred for 15-20 min, and then held at that temperature for 30-40 min. Subsequently, 0.3% to 0.4% of hexachloroethane by mass of the melt is added as a refining agent for refining. After slag removal and degassing, the material is allowed to stand and then poured into a preheated mold. The resulting material is then heat-treated to obtain lightweight high-strength aluminum alloy profiles for automobiles.

10. The manufacturing process of a lightweight high-strength aluminum alloy profile for automobiles according to claim 9, characterized in that, The heat treatment includes first holding at 500-540℃ for 4-5 hours, then quenching in water at 60-100℃, and finally aging at 160-170℃ for 4-6 hours, followed by air cooling.

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