High-thermal-conductivity aluminum alloy composite material and preparation method thereof

Abstract

The invention provides a high thermal conductivity aluminum alloy composite material, the aluminum alloy composite material comprises an aluminum alloy and a cerium / scandium composite aerogel heat conduction support, the heat conduction support accounts for 10-20 vt% of the aluminum alloy composite material, and the aluminum alloy comprises the following components in parts by weight: 0.45-0.9 wt% of Mg; 0.2 to 0.6 wt% of Si; mn is 0.1 to 0.3 wt%; 0.1 to 0.4 wt% of Cr; 0.05 to 0.2 wt% of Cu; 0.15 to 0.25 wt% of Fe; 0.12 to 0.2 wt% of Ti; the balance is Al; the cerium / scandium composite aerogel heat conduction support is cellulose carbon aerogel with directional orientation, and cerium / scandium composite rare earth oxide is loaded on the carbon aerogel. According to the present invention, the aluminum alloy material and the composite aerogel support are compounded, and the composite aerogel is formed by compounding the carbon support, the carbon nanotube and the composite rare earth oxide, such that the good heat conduction effect is provided;

Description

Technical Field

[0001] The present invention relates to the field of metal alloy materials, and in particular to a high thermal conductivity aluminum alloy composite material and a preparation method thereof. Background Art

[0002] Many new heat sink materials currently used on the market are aluminum alloys, taking into account a combination of thermal conductivity, price, and total content in the Earth's crust. Because my country is a major aluminum producer, and aluminum heat sinks are widely used in computers and automobiles, the market demand and development prospects for aluminum heat sinks in my country are enormous. Aluminum possesses excellent thermal conductivity, high specific strength, and high specific stiffness. Compared to metals with high thermal conductivity, such as gold, silver, copper, and aluminum, aluminum offers the advantage of low price and low specific gravity, resulting in higher heat dissipation capacity per unit weight than copper. Furthermore, its excellent ductility makes aluminum alloys easier to form during casting and extrusion. With the development of the computer industry, computers are now not only portable but also powerful, placing higher demands on the thermal conductivity of alloy materials. Theoretically, metals with high thermal conductivity are ideal for computer heat sinks. Silver has the highest thermal conductivity, followed by copper, gold, and finally pure aluminum (226W / m·K). Silver and gold are relatively expensive. Copper's thermal conductivity is almost twice that of aluminum, but its heat dissipation efficiency is not as good as aluminum's. Copper is more expensive and of higher quality than aluminum, and is difficult to process, weld, and form. Therefore, aluminum is a more suitable choice based on comprehensive considerations. Aluminum heat sink profiles are easy to process, lightweight, and require less metal (the metal's thermal strength can reach 2.0-3.0W / kg·°C), offering energy-saving and material-saving advantages. However, pure aluminum cannot be used directly in computer heat sinks due to its insufficient strength, poor machinability, tool sticking, and difficulty in forming. Generally speaking, pure metals have better thermal conductivity than their alloys. To achieve better metalworking properties than pure aluminum, manufacturers typically use aluminum alloys to manufacture their products. Computer heat sinks currently on the market are generally made of 6063 aluminum alloy. However, the heat dissipation capacity of heat sinks made from these materials is insufficient, a bottleneck restricting the development of computers. Therefore, research and development of new aluminum alloy computer heat sink materials is crucial for the advancement of miniaturization and high-speed computers. This makes the development of new heat sink materials with high thermal conductivity and performance particularly important. Summary of the Invention

[0003] Technical problem to be solved: The purpose of the present invention is to provide a high thermal conductivity aluminum alloy composite material, which is prepared by compositely preparing an aluminum alloy material and a thermal conductive bracket to improve the thermal conductivity of the aluminum alloy.

[0004] Technical solution: A high thermal conductivity aluminum alloy composite material, the aluminum alloy composite material includes aluminum alloy and cerium / scandium composite aerogel thermal conductive bracket, the thermal conductive bracket accounts for 10-20vt% of the aluminum alloy composite material, the aluminum alloy includes the following components by weight: Mg 0.45-0.9wt% Si 0.2-0.6wt% Mn 0.1-0.3wt% Cr 0.1-0.4wt% Cu 0.05-0.2wt% Fe 0.15-0.25wt% Ti 0.12-0.2wt% The remainder is Al; The cerium / scandium composite aerogel heat-conducting bracket is a cellulose carbon aerogel with a directional orientation, and the carbon aerogel is loaded with a cerium / scandium composite rare earth oxide. Preferably, the preparation method of the cerium / scandium composite aerogel thermal conductive bracket comprises the following steps: S1. Adding cellulose to water to prepare a cellulose suspension; S2. Add carbon nanotubes to the suspension prepared in step S1 and stir at high speed to obtain a mixed suspension; S3. The mixed suspension is placed in a mold and first frozen with liquid nitrogen, and then subjected to directional freeze drying to obtain an oriented cellulose / carbon nanotube aerogel. The cellulose / carbon nanotube aerogel is pyrolyzed under a nitrogen atmosphere to obtain a nanocellulose carbon aerogel; S4. The nanocellulose carbon aerogel was added to the cerium nitrate solution, and after sufficient adsorption, freeze-dried to obtain a nanocellulose carbon aerogel loaded with cerium nitrate; S5. Add the nanocellulose carbon aerogel loaded with cerium nitrate to a mixed solution of citric acid and scandium nitrate. After stirring and adsorption, add ammonia water dropwise to the solution and adjust the pH to 2 to obtain a cerium / scandium composite aerogel material precursor. Age the aerogel and then calcine to obtain a cerium / scandium composite aerogel material. Preferably, the concentration of the cellulose suspension is 1.5-3 wt%. Preferably, the content of carbon nanotubes in the mixed suspension is 0.5-1.2 wt%. Preferably, the directional freeze-drying temperature is -80 to -40°C, and the time is 30 to 60 hours. Preferably, the initial heating rate of the pyrolysis is 2-3°C / min to 450-500°C, kept at this temperature for 1 hour, and then the heating rate is increased to 3-5°C / min to 950-1000°C. Preferably, the concentration of the cerium nitrate solution is 0.1-0.2 mol / L, the freeze-drying temperature is -40 to -20°C, and the time is 5-10 hours. Preferably, the concentrations of citric acid and scandium nitrate in the mixed solution are 0.1-0.2 mol / L, the mass fraction of the ammonia solution is 20-30 wt%, the aging parameters are aging at 100-120°C for 5-15 hours, and the calcination temperature is calcination at 800-900°C for 2-4 hours. The method for preparing the above-mentioned high thermal conductivity aluminum alloy composite material comprises the following steps: The various components of the aluminum alloy are mixed and melted at a temperature of 800-830°C, added to a mold containing a cerium / scandium composite aerogel thermal conductive bracket, and homogenized at 550-580°C for 5-8 hours. Then, an aging treatment is performed at 200-220°C for 5-10 hours to obtain a high thermal conductivity aluminum alloy composite material. Beneficial effects: The high thermal conductivity aluminum alloy composite material of the present invention has the following advantages: 1. The present invention adopts aluminum alloy material and composite aerogel bracket, and the composite aerogel is composed of carbon bracket, carbon nanotubes and composite rare earth oxide, which has good thermal conductivity; 2. The carbon scaffold in this invention is prepared by a unidirectional freeze-drying method. The scaffold has a parallel structure, allowing heat to dissipate along the scaffold. Furthermore, carbon nanotubes are incorporated into the scaffold to form heat conduction channels, further enhancing the heat dissipation effect. 3. The present invention adopts cerium / scandium composite rare earth oxide. Cerium belongs to light rare earth and scandium belongs to heavy rare earth. The combination of two different rare earth elements has a strong degassing effect, which greatly reduces the pinhole rate in the structure; at the same time, it significantly reduces the number of inclusions in the aluminum alloy structure and enhances the density of the alloy cast structure; it also has a metamorphic effect, effectively controlling the solid solubility of excess elements, thereby improving the thermal conductivity. 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 thermal conductivity aluminum alloy composite material, the aluminum alloy composite material includes an aluminum alloy and a cerium / scandium composite aerogel thermal conductive bracket, the thermal conductive bracket accounts for 15.2vt% of the aluminum alloy composite material, and the aluminum alloy includes the following components by weight: Mg 0.45wt% Si 0.6wt% Mn 0.1wt% Cr 0.4wt% Cu 0.05wt% Fe 0.25wt% Ti 0.2wt% The remainder is Al; The cerium / scandium composite aerogel thermal conductive support is a cellulose carbon aerogel with a directional orientation, and the carbon aerogel is loaded with a cerium / scandium composite rare earth oxide; The method for preparing the above-mentioned high thermal conductivity aluminum alloy composite material comprises the following steps: The aluminum alloy components were mixed and smelted at 800°C, added to a mold containing a cerium / scandium composite aerogel thermal conductive support, and homogenized at 580°C for 5 hours, followed by aging treatment at 220°C for 10 hours to obtain a high thermal conductivity aluminum alloy composite material. The preparation method of the cerium / scandium composite aerogel thermal conductive bracket comprises the following steps: S1. Cellulose was added to water to prepare a 1.5 wt% cellulose suspension; S2 carbon nanotubes were added to the suspension prepared in step S1 and stirred at high speed to obtain a mixed suspension, wherein the content of carbon nanotubes in the mixed suspension was 1.2 wt%; S3. The mixed suspension was placed in a mold and first frozen with liquid nitrogen, followed by directional freeze drying at -80°C for 30 hours to obtain an oriented cellulose / carbon nanotube aerogel. The cellulose / carbon nanotube aerogel was then pyrolyzed in a nitrogen atmosphere at an initial heating rate of 2°C / min to 450°C, held for 1 hour, and then increased to a heating rate of 5°C / min to 1000°C to obtain a nanocellulose carbon aerogel. S4. The nanocellulose carbon aerogel was added to a 0.1 mol / L cerium nitrate solution and freeze-dried after sufficient adsorption. The freeze-drying temperature was -20 ° C for 10 h to obtain a nanocellulose carbon aerogel loaded with cerium nitrate; S5. The nanocellulose carbon aerogel loaded with cerium nitrate was added to a mixed solution of citric acid and 0.1 mol / L scandium nitrate. After stirring and adsorption, 20 wt% ammonia water was added dropwise to the solution and the pH was adjusted to 2 to obtain a cerium / scandium composite aerogel material precursor. The aerogel was aged at 100°C for 15 h and then calcined at 900°C for 2 h to obtain a cerium / scandium composite aerogel material. Example 2 A high thermal conductivity aluminum alloy composite material, the aluminum alloy composite material includes aluminum alloy and cerium / scandium composite aerogel thermal conductive bracket, the thermal conductive bracket accounts for 16.1vt% of the aluminum alloy composite material, and the aluminum alloy includes the following components by weight: Mg 0.9wt% Si 0.2wt% Mn 0.3wt% Cr 0.1wt% Cu 0.2wt% Fe 0.15wt% Ti 0.12wt% The remainder is Al; The cerium / scandium composite aerogel thermal conductive support is a cellulose carbon aerogel with a directional orientation, and the carbon aerogel is loaded with a cerium / scandium composite rare earth oxide; The method for preparing the above-mentioned high thermal conductivity aluminum alloy composite material comprises the following steps: The aluminum alloy components were mixed and melted at 830°C, added to a mold containing a cerium / scandium composite aerogel thermal conductive support, and homogenized at 550°C for 8 hours. Then, the mixture was aged at 200°C for 5 hours to obtain a high thermal conductivity aluminum alloy composite material. The preparation method of the cerium / scandium composite aerogel thermal conductive bracket comprises the following steps: S1. Cellulose was added to water to prepare a 3 wt% cellulose suspension; S2. CNTs were added to the suspension prepared in step S1 and stirred at high speed to obtain a mixed suspension, wherein the content of CNTs in the mixed suspension was 0.5 wt %; S3. The mixed suspension was placed in a mold and first frozen with liquid nitrogen, and then subjected to directional freeze drying at -40°C for 60 hours to obtain an oriented cellulose / carbon nanotube aerogel. The cellulose / carbon nanotube aerogel was pyrolyzed in a nitrogen atmosphere at an initial heating rate of 3°C / min to 500°C, held at that temperature for 1 hour, and then increased to a heating rate of 3°C / min to 950°C to obtain a nanocellulose carbon aerogel. S4. The nanocellulose carbon aerogel was added to a 0.2 mol / L cerium nitrate solution and freeze-dried after sufficient adsorption at a temperature of -40°C for 5 h to obtain a nanocellulose carbon aerogel loaded with cerium nitrate; S5. The nanocellulose carbon aerogel loaded with cerium nitrate was added to a mixed solution of citric acid and 0.2 mol / L scandium nitrate. After stirring and adsorption, 30 wt% ammonia water was added dropwise to the solution and the pH was adjusted to 2 to obtain a cerium / scandium composite aerogel material precursor. The aerogel was aged at 120°C for 5 h and then calcined at 800°C for 4 h to obtain a cerium / scandium composite aerogel material. Example 3 A high thermal conductivity aluminum alloy composite material, the aluminum alloy composite material includes aluminum alloy and cerium / scandium composite aerogel thermal conductive bracket, the thermal conductive bracket accounts for 14.3vt% of the aluminum alloy composite material, and the aluminum alloy includes the following components by weight: Mg 0.55wt% Si 0.5wt% Mn 0.15wt% Cr 0.2wt% Cu 0.1wt% Fe 0.2wt% Ti 0.18wt% The remainder is Al; The cerium / scandium composite aerogel thermal conductive support is a cellulose carbon aerogel with a directional orientation, and the carbon aerogel is loaded with a cerium / scandium composite rare earth oxide; The method for preparing the above-mentioned high thermal conductivity aluminum alloy composite material comprises the following steps: The aluminum alloy components were mixed and melted at 810°C, added to a mold containing a cerium / scandium composite aerogel thermal conductive support, and homogenized at 580°C for 6 hours. Then, the mixture was aged at 200°C for 9 hours to obtain a high thermal conductivity aluminum alloy composite material. The preparation method of the cerium / scandium composite aerogel thermal conductive bracket comprises the following steps: S1. Cellulose was added to water to prepare a 1.8 wt% cellulose suspension; S2. CNTs were added to the suspension prepared in step S1 and stirred at high speed to obtain a mixed suspension, wherein the content of CNTs in the mixed suspension was 1.0 wt %; S3. The mixed suspension was placed in a mold and first frozen in liquid nitrogen, followed by directional freeze drying at -70°C for 40 hours to obtain an oriented cellulose / carbon nanotube aerogel. The cellulose / carbon nanotube aerogel was then pyrolyzed in a nitrogen atmosphere at an initial heating rate of 2°C / min to 460°C, held for 1 hour, and then increased to a heating rate of 3°C / min to 960°C to obtain a nanocellulose carbon aerogel. S4. The nanocellulose carbon aerogel was added to a 0.1 mol / L cerium nitrate solution and then fully adsorbed and freeze-dried at a temperature of -40°C for 6 h to obtain a nanocellulose carbon aerogel loaded with cerium nitrate; S5. The nanocellulose carbon aerogel loaded with cerium nitrate was added to a mixed solution of citric acid and 0.1 mol / L scandium nitrate. After stirring and adsorption, 22 wt% ammonia water was added dropwise to the solution and the pH was adjusted to 2 to obtain a cerium / scandium composite aerogel material precursor. The aerogel was aged at 115°C for 8 h and then calcined at 830°C for 2.5 h to obtain a cerium / scandium composite aerogel material. Example 4 A high thermal conductivity aluminum alloy composite material, the aluminum alloy composite material includes aluminum alloy and cerium / scandium composite aerogel thermal conductive bracket, the thermal conductive bracket accounts for 16.1vt% of the aluminum alloy composite material, and the aluminum alloy includes the following components by weight: Mg 0.8wt% Si 0.3wt% Mn 0.25wt% Cr 0.3wt% Cu 0.15wt% Fe 0.25wt% Ti 0.15wt% The remainder is Al; The cerium / scandium composite aerogel thermal conductive support is a cellulose carbon aerogel with a directional orientation, and the carbon aerogel is loaded with a cerium / scandium composite rare earth oxide; The method for preparing the above-mentioned high thermal conductivity aluminum alloy composite material comprises the following steps: The aluminum alloy components were mixed and smelted at 820°C, added to a mold containing a cerium / scandium composite aerogel thermal conductive support, and homogenized at 560°C for 7 hours, followed by aging treatment at 220°C for 6 hours to obtain a high thermal conductivity aluminum alloy composite material. The preparation method of the cerium / scandium composite aerogel thermal conductive bracket comprises the following steps: S1. Cellulose was added to water to prepare a 2.5 wt% cellulose suspension; S2. CNTs were added to the suspension prepared in step S1 and stirred at high speed to obtain a mixed suspension, wherein the content of CNTs in the mixed suspension was 0.7 wt %; S3. The mixed suspension was placed in a mold and first frozen with liquid nitrogen, and then subjected to directional freeze drying at -50°C for 50 hours to obtain an oriented cellulose / carbon nanotube aerogel. The cellulose / carbon nanotube aerogel was pyrolyzed in a nitrogen atmosphere at an initial heating rate of 3°C / min to 480°C, held at that temperature for 1 hour, and then increased to a heating rate of 5°C / min to 980°C to obtain a nanocellulose carbon aerogel. S4. The nanocellulose carbon aerogel was added to a 0.2 mol / L cerium nitrate solution and freeze-dried after sufficient adsorption at a temperature of -20°C for 9 h to obtain a nanocellulose carbon aerogel loaded with cerium nitrate; S5. The nanocellulose carbon aerogel loaded with cerium nitrate was added to a mixed solution of citric acid and 0.2 mol / L scandium nitrate. After stirring and adsorption, 26 wt% ammonia water was added dropwise to the solution and the pH was adjusted to 2 to obtain a cerium / scandium composite aerogel material precursor. The aerogel was aged at 105°C for 12 h and then calcined at 880°C for 3.5 h to obtain a cerium / scandium composite aerogel material. Example 5 A high thermal conductivity aluminum alloy composite material, comprising an aluminum alloy and a cerium / scandium composite aerogel thermal conductive support, wherein the thermal conductive support accounts for 15vt% of the aluminum alloy composite material, and the aluminum alloy comprises the following components in parts by weight: Mg 0.65wt% Si 0.4wt% Mn 0.2wt% Cr 0.25wt% Cu 0.12wt% Fe 0.22wt% Ti 0.16wt% The remainder is Al; The cerium / scandium composite aerogel thermal conductive support is a cellulose carbon aerogel with a directional orientation, and the carbon aerogel is loaded with a cerium / scandium composite rare earth oxide; The method for preparing the above-mentioned high thermal conductivity aluminum alloy composite material comprises the following steps: The aluminum alloy components were mixed and smelted at 810°C, added to a mold containing a cerium / scandium composite aerogel thermal conductive support, and homogenized at 570°C for 6.5 hours. Then, the mixture was aged at 210°C for 8 hours to obtain a high thermal conductivity aluminum alloy composite material. The preparation method of the cerium / scandium composite aerogel thermal conductive bracket comprises the following steps: S1. Cellulose was added to water to prepare a cellulose suspension with a concentration of 2.2 wt%; S2. CNTs were added to the suspension prepared in step S1 and stirred at high speed to obtain a mixed suspension, wherein the content of CNTs in the mixed suspension was 0.9 wt %; S3. The mixed suspension was placed in a mold and first frozen in liquid nitrogen, followed by directional freeze drying at -60°C for 45 hours to obtain an oriented cellulose / carbon nanotube aerogel. The cellulose / carbon nanotube aerogel was then pyrolyzed in a nitrogen atmosphere at an initial heating rate of 2.5°C / min to 47°C, held for 1 hour, and then increased to a heating rate of 4°C / min to 970°C to obtain a nanocellulose carbon aerogel. S4. The nanocellulose carbon aerogel was added to a 0.15 mol / L cerium nitrate solution and then fully adsorbed and freeze-dried at a temperature of -30°C for 8 h to obtain a nanocellulose carbon aerogel loaded with cerium nitrate; S5. The nanocellulose carbon aerogel loaded with cerium nitrate was added to a mixed solution of citric acid and 0.15 mol / L scandium nitrate. After stirring and adsorption, 24 wt% ammonia water was added dropwise to the solution and the pH was adjusted to 2 to obtain a cerium / scandium composite aerogel material precursor. The aerogel was aged at 1105°C for 10 h and then calcined at 850°C for 3 h to obtain a cerium / scandium composite aerogel material. Comparative Example 1 A high thermal conductivity aluminum alloy composite material, comprising an aluminum alloy and a cerium composite aerogel thermal conductive bracket, wherein the thermal conductive bracket accounts for 13.6vt% of the aluminum alloy composite material, and the aluminum alloy comprises the following components in parts by weight: Mg 0.8wt% Si 0.3wt% Mn 0.25wt% Cr 0.3wt% Cu 0.15wt% Fe 0.25wt% Ti 0.15wt% The remainder is Al; The cerium composite aerogel thermal conductive bracket is a cellulose carbon aerogel with a directional orientation, and cerium oxide is loaded on the carbon aerogel. The preparation method of the above-mentioned high thermal conductivity aluminum alloy composite material includes the following steps: The aluminum alloy components were mixed and smelted at 820°C, added to a mold containing a cerium / scandium composite aerogel thermal conductive support, and homogenized at 560°C for 7 hours, followed by aging treatment at 220°C for 6 hours to obtain a high thermal conductivity aluminum alloy composite material. The preparation method of the cerium composite aerogel thermal conductive bracket comprises the following steps: S1. Cellulose was added to water to prepare a 2.5 wt% cellulose suspension; S2. CNTs were added to the suspension prepared in step S1 and stirred at high speed to obtain a mixed suspension, wherein the content of CNTs in the mixed suspension was 0.7 wt %; S3. The mixed suspension was placed in a mold and first frozen with liquid nitrogen, and then subjected to directional freeze drying at -50°C for 50 hours to obtain an oriented cellulose / carbon nanotube aerogel. The cellulose / carbon nanotube aerogel was pyrolyzed in a nitrogen atmosphere at an initial heating rate of 3°C / min to 480°C, held at that temperature for 1 hour, and then increased to a heating rate of 5°C / min to 980°C to obtain a nanocellulose carbon aerogel. S4. Add the nanocellulose carbon aerogel to a mixed solution of citric acid and 0.2 mol / L cerium nitrate, stir and adsorb, then add 26 wt% ammonia water to the solution and adjust the pH to 2 to obtain a cerium composite aerogel material precursor. The aerogel is aged at 105°C for 12 h and then calcined at 880°C for 3.5 h to obtain a cerium composite aerogel material. Comparative Example 2 A high thermal conductivity aluminum alloy composite material, the aluminum alloy composite material includes an aluminum alloy and a cerium / lanthanum composite aerogel thermal conductive bracket, the thermal conductive bracket accounts for 15.5vt% of the aluminum alloy composite material, and the aluminum alloy includes the following components by weight: Mg 0.8wt% Si 0.3wt% Mn 0.25wt% Cr 0.3wt% Cu 0.15wt% Fe 0.25wt% Ti 0.15wt% The remainder is Al; The cerium / lanthanum composite aerogel thermal conductive support is a cellulose carbon aerogel with a directional orientation, and the carbon aerogel is loaded with a cerium / lanthanum composite rare earth oxide; The method for preparing the above-mentioned high thermal conductivity aluminum alloy composite material comprises the following steps: The aluminum alloy components were mixed and smelted at 820°C, added to a mold containing a cerium / scandium composite aerogel thermal conductive support, and homogenized at 560°C for 7 hours, followed by aging treatment at 220°C for 6 hours to obtain a high thermal conductivity aluminum alloy composite material. The preparation method of the cerium / lanthanum composite aerogel thermal conductive bracket comprises the following steps: S1. Cellulose was added to water to prepare a 2.5 wt% cellulose suspension; S2. CNTs were added to the suspension prepared in step S1 and stirred at high speed to obtain a mixed suspension, wherein the content of CNTs in the mixed suspension was 0.7 wt %; S3. The mixed suspension was placed in a mold and first frozen with liquid nitrogen, and then subjected to directional freeze drying at -50°C for 50 hours to obtain an oriented cellulose / carbon nanotube aerogel. The cellulose / carbon nanotube aerogel was pyrolyzed in a nitrogen atmosphere at an initial heating rate of 3°C / min to 480°C, held at that temperature for 1 hour, and then increased to a heating rate of 5°C / min to 980°C to obtain a nanocellulose carbon aerogel. S4. The nanocellulose carbon aerogel was added to a 0.2 mol / L cerium nitrate solution and freeze-dried after sufficient adsorption at a temperature of -20°C for 9 h to obtain a nanocellulose carbon aerogel loaded with cerium nitrate; S5. The nanocellulose carbon aerogel loaded with cerium nitrate was added to a mixed solution of citric acid and 0.2 mol / L lanthanum nitrate. After stirring and adsorption, 26 wt% ammonia water was added dropwise to the solution and the pH was adjusted to 2 to obtain a cerium / lanthanum composite aerogel material precursor. The aerogel was aged at 105°C for 12 h and then calcined at 880°C for 3.5 h to obtain a cerium / scandium composite aerogel material. Comparative Example 3 A high thermal conductivity aluminum alloy composite material, the aluminum alloy composite material includes aluminum alloy and cerium / scandium composite aerogel thermal conductive bracket, the thermal conductive bracket accounts for 16.8vt% of the aluminum alloy composite material, and the aluminum alloy includes the following components by weight: Mg 0.8wt% Si 0.3wt% Mn 0.25wt% Cr 0.3wt% Cu 0.15wt% Fe 0.25wt% Ti 0.15wt% The remainder is Al; The cerium / scandium composite aerogel thermal conductive support is a cellulose carbon aerogel with a directional orientation, and the carbon aerogel is loaded with a cerium / scandium composite rare earth oxide; The method for preparing the above-mentioned high thermal conductivity aluminum alloy composite material comprises the following steps: The aluminum alloy components were mixed and smelted at 820°C, added to a mold containing a cerium / scandium composite aerogel thermal conductive support, and homogenized at 560°C for 7 hours, followed by aging treatment at 220°C for 6 hours to obtain a high thermal conductivity aluminum alloy composite material. The preparation method of the cerium / scandium composite aerogel thermal conductive bracket comprises the following steps: S1. Cellulose was added to water to prepare a 2.5 wt% cellulose suspension; S2. CNTs were added to the suspension prepared in step S1 and stirred at high speed to obtain a mixed suspension, wherein the content of CNTs in the mixed suspension was 0.7 wt %; S3. The mixed suspension was placed in a mold and first frozen in liquid nitrogen, and then freeze-dried at -40°C for 60 hours to obtain a cellulose / carbon nanotube aerogel. The cellulose / carbon nanotube aerogel was pyrolyzed in a nitrogen atmosphere at an initial heating rate of 3°C / min to 480°C, held for 1 hour, and then increased to a heating rate of 5°C / min to 980°C to obtain a nanocellulose carbon aerogel. S4. The nanocellulose carbon aerogel was added to a 0.2 mol / L cerium nitrate solution and freeze-dried after sufficient adsorption at a temperature of -20°C for 9 h to obtain a nanocellulose carbon aerogel loaded with cerium nitrate; S5. The nanocellulose carbon aerogel loaded with cerium nitrate was added to a mixed solution of citric acid and 0.2 mol / L scandium nitrate. After stirring and adsorption, 26 wt% ammonia water was added dropwise to the solution and the pH was adjusted to 2 to obtain a cerium / scandium composite aerogel material precursor. The aerogel was aged at 105°C for 12 h and then calcined at 880°C for 3.5 h to obtain a cerium / scandium composite aerogel material. Comparative Example 4 A high thermal conductivity aluminum alloy composite material, the aluminum alloy composite material includes aluminum alloy and cerium / scandium composite aerogel thermal conductive bracket, the thermal conductive bracket accounts for 15.2vt% of the aluminum alloy composite material, and the aluminum alloy includes the following components by weight: Mg 0.8wt% Si 0.3wt% Mn 0.25wt% Cr 0.3wt% Cu 0.15wt% Fe 0.25wt% Ti 0.15wt% The remainder is Al; The cerium / scandium composite aerogel thermal conductive support is a cellulose carbon aerogel with a directional orientation, and the carbon aerogel is loaded with a cerium / scandium composite rare earth oxide; The method for preparing the above-mentioned high thermal conductivity aluminum alloy composite material comprises the following steps: The aluminum alloy components were mixed and smelted at 820°C, added to a mold containing a cerium / scandium composite aerogel thermal conductive support, and homogenized at 560°C for 7 hours, followed by aging treatment at 220°C for 6 hours to obtain a high thermal conductivity aluminum alloy composite material. The preparation method of the cerium / scandium composite aerogel thermal conductive bracket comprises the following steps: S1. Cellulose was added to water to prepare a 2.5 wt% cellulose suspension; S2. The cellulose suspension was placed in a mold and first frozen with liquid nitrogen. The oriented freeze-drying temperature was -50°C for 50 hours to obtain an oriented cellulose / carbon nanotube aerogel. The cellulose / carbon nanotube aerogel was then pyrolyzed in a nitrogen atmosphere at an initial heating rate of 3°C / min to 480°C, held at that temperature for 1 hour, and then increased to a heating rate of 5°C / min to 980°C to obtain a nanocellulose carbon aerogel. S3. The nanocellulose carbon aerogel was added to a 0.2 mol / L cerium nitrate solution and then fully adsorbed and freeze-dried at a temperature of -20°C for 9 h to obtain a nanocellulose carbon aerogel loaded with cerium nitrate; S4. The nanocellulose carbon aerogel loaded with cerium nitrate was added to a mixed solution of citric acid and 0.2 mol / L scandium nitrate. After stirring and adsorption, 26 wt% ammonia water was added dropwise to the solution and the pH was adjusted to 2 to obtain a cerium / scandium composite aerogel material precursor. The aerogel was aged at 105°C for 12 h and then calcined at 880°C for 3.5 h to obtain a cerium / scandium composite aerogel material. Thermal conductivity test: The sample to be tested was processed into a 10mm*10mm*2mm thin sheet (the bracket was processed according to the test sample) and tested using a laser thermal conductivity meter to obtain the thermal diffusivity of the sample at room temperature (25°C). The thermal conductivity of the sample was then substituted into the following thermal conductivity formula to calculate its thermal conductivity and obtain its thermal conductivity performance. λ=αρCp*100 Where: λ is the thermal conductivity of the sample being measured, in W / m·K; α is the thermal diffusivity of the sample being measured, in cm 2 / s, ρ is the density of the sample being tested, in g / cm 3 ; Cp is the specific heat capacity of the sample being tested, in J / g·K. Thermal conductivity W / m·K Example 1 231 Example 2 228 Example 3 229 Example 4 232 Example 5 236 Comparative Example 1 201 Comparative Example 2 211 Comparative Example 3 198 Comparative Example 4 186 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 thermal conductivity aluminum alloy composite material, characterized in that: The aluminum alloy composite material comprises an aluminum alloy and a cerium / scandium composite aerogel thermal conductive support, wherein the thermal conductive support accounts for 10-20vt% of the aluminum alloy composite material, and the aluminum alloy comprises the following components by weight: Mg 0.45-0.9wt% Si 0.2-0.6wt% Mn 0.1-0.3wt% Cr 0.1-0.4wt% Cu 0.05-0.2wt% Fe 0.15-0.25wt% Ti 0.12-0.2wt% The balance is Al; The cerium / scandium composite aerogel heat-conducting support is a cellulose carbon aerogel with directional orientation, and the carbon aerogel is loaded with a cerium / scandium composite rare earth oxide.

2. The high thermal conductivity aluminum alloy composite material according to claim 1, characterized in that: The preparation method of the cerium / scandium composite aerogel thermal conductive bracket comprises the following steps: S1. adding cellulose to water to prepare a cellulose suspension; S2. Add carbon nanotubes to the suspension prepared in step S1, and stir at high speed to obtain a mixed suspension; S3. The mixed suspension is placed in a mold and first frozen with liquid nitrogen, and then subjected to directional freeze drying to obtain an oriented cellulose / carbon nanotube aerogel, and the cellulose / carbon nanotube aerogel is pyrolyzed in a nitrogen atmosphere to obtain a nanocellulose carbon aerogel; S4. adding the nanocellulose carbon aerogel to the cerium nitrate solution, and freeze-drying after sufficient adsorption to obtain the nanocellulose carbon aerogel loaded with cerium nitrate; S5. Add the nanocellulose carbon aerogel loaded with cerium nitrate to a mixed solution of citric acid and scandium nitrate, stir and adsorb, then add ammonia water to the solution, adjust the pH to 2, and obtain a cerium / scandium composite aerogel material precursor, age the aerogel, and then calcine to obtain a cerium / scandium composite aerogel material.

3. The high thermal conductivity aluminum alloy composite material according to claim 2, characterized in that: The concentration of the cellulose suspension is 1.5-3 wt %.

4. The high thermal conductivity aluminum alloy composite material according to claim 2, characterized in that: The content of carbon nanotubes in the mixed suspension is 0.5-1.2 wt %.

5. The high thermal conductivity aluminum alloy composite material according to claim 2, characterized in that: The temperature of the directional freeze drying is -80 to -40°C, and the time is 30 to 60 hours.

6. The high thermal conductivity aluminum alloy composite material according to claim 2, characterized in that: The initial heating rate of the pyrolysis is 2-3°C / min to heat to 450-500°C, and the temperature is kept for 1 hour, and then the heating rate is increased to 3-5°C / min to heat to 950-1000°C.

7. The high thermal conductivity aluminum alloy composite material according to claim 2, characterized in that: The concentration of the cerium nitrate solution is 0.1-0.2 mol / L, the freeze-drying temperature is -40 to -20°C, and the time is 5-10 hours.

8. The high thermal conductivity aluminum alloy composite material according to claim 2, characterized in that: The concentrations of citric acid and scandium nitrate in the mixed solution are 0.1-0.2 mol / L, the mass fraction of the ammonia solution is 20-30 wt%, the aging parameters are aging at 100-120° C. for 5-15 h, and the calcination temperature is calcining at 800-900° C. for 2-4 h.

9. The method for preparing a high thermal conductivity aluminum alloy composite material according to claim 1, characterized in that: The following steps are involved: The various components of the aluminum alloy are mixed and melted at a temperature of 800-830°C, added into a mold containing a cerium / scandium composite aerogel thermal conductive support, homogenized at 550-580°C for 5-8h, and then aged at 200-220°C for 5-10h to obtain a high thermal conductivity aluminum alloy composite material.