Preparation method of high-thermal-conductivity silicon carbide particle reinforced aluminum-based composite material

Abstract

The invention provides a preparation method of a high-thermal-conductivity silicon carbide particle reinforced aluminum-based composite material. The preparation method comprises the following steps: step 1, shaping silicon carbide particles; step 2, mechanical mixing; step 3, packaging; step 4, carrying out vacuum hot degassing; and fifthly, hot isostatic pressing treatment is conducted, specifically, the ingot blank is put into a hot isostatic pressing machine to be subjected to hot isostatic pressing, then an aluminum sheath of the ingot blank is removed through machining, and the high-thermal-conductivity silicon carbide particle reinforced aluminum-based composite material is obtained. According to the preparation method of the high-thermal-conductivity silicon carbide particle reinforced aluminum-based composite material, the preparation process of the high-thermal-conductivity aluminum-based composite material can be optimized, the specific surface area of particles is reduced, the bonding interface area of the composite material is reduced, and the thermal resistance of the composite material is reduced; the heat-conducting property of the composite material is improved; and the stress around the silicon carbide particles can be more uniform, and the mechanical property is better.

Description

Technical Field

[0001] The present invention relates to the technical field of metal matrix composite materials, and in particular to a method for preparing a high thermal conductivity silicon carbide particle reinforced aluminum matrix composite material. Background Art

[0002] In recent years, in order to meet the development needs of electronic technology, great progress has been made in the research of high thermal conductivity and low expansion metal matrix composites used as thermal management materials. Particle-reinforced aluminum matrix composites have become an ideal choice for future electronic packaging materials due to their comprehensive advantages of lightweight aluminum matrix and reinforcement particles, high thermal conductivity and low expansion. Among them, silicon carbide particle-reinforced aluminum matrix composites have received widespread attention.

[0003] At present, silicon carbide particles reinforced aluminum-based composite materials for electronic packaging mainly adopt a higher volume fraction of reinforcement to obtain high thermal conductivity and thermal expansion coefficient matching with the chip. However, silicon carbide particles are prone to interface reaction with aluminum matrix to generate rod-shaped or flaky A14C3 phases. Due to the low thermal conductivity of A14C3, the thermal conductivity of the composite interface is low. In order to solve the serious interface reaction of Al / SiC, the existing patent CN114480942A reduces the material preparation temperature to achieve the purpose of reducing the interface reaction. However, due to the poor wettability of Al and SiC, the composite interface of the material prepared at low temperature cannot form an effective combination, resulting in poor comprehensive performance of the material. Another method to reduce the generation of Al4C3 at the interface is to plate other materials on the surface of SiC particles for surface modification, such as plating metal elements such as Ni and Cu, but these elements will also react to generate other interface phases. Its main purpose is to reduce the generation of brittle phase A14C3 and thus improve the mechanical properties of the material, and it has limited effect on reducing the interface thermal resistance. Patent CN104264000B provides a method for preparing a graphene-modified high thermal conductivity aluminum-based composite material. Graphene nanosheets are used to modify and coat the surface of the reinforcement particles. Although the generation of interfacial reaction phases is avoided, the preparation process is long and the raw material price is high, and its promotion and application in the field of thermal management is severely limited.

[0004] In order to obtain high thermal conductivity silicon carbide reinforced aluminum-based composite materials, reducing the composite interface area to reduce the interface thermal resistance is a feasible method to improve the thermal conductivity of the material. However, the SiC particles currently used in high thermal conductivity aluminum-based composite materials are mostly obtained by artificial synthesis and mechanical crushing. Due to the low fracture toughness of SiC (high brittleness), SiC often cleaves along different crystal planes during the crushing process, so it has an irregular shape and a high specific surface area of ​​the particles, which increases the interface area of ​​the composite material and significantly reduces its thermal conductivity. Therefore, it is of great significance to study how to reduce the bonding interface and improve the high thermal conductivity of aluminum-based composite materials. Summary of the invention

[0005] In view of this, the present invention aims to propose a method for preparing a high thermal conductivity silicon carbide particle reinforced aluminum-based composite material to solve the problem of reduced thermal conductivity of the composite material caused by the irregular shape of SiC particles and the high specific surface area of ​​the particles in the prior art; thereby optimizing the preparation process of the high thermal conductivity aluminum-based composite material, improving the morphology of SiC particles, reducing the specific surface area of ​​the particles, reducing the bonding interface area of ​​the composite material, reducing the amount of Al4C3 phase generated at the interface, and reducing the thermal resistance of the composite material; improving the thermal conductivity of the composite material; and making the stress around the silicon carbide particles more uniform and the mechanical properties better.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] The present invention relates to a method for preparing a high thermal conductivity silicon carbide particle reinforced aluminum-based composite material, comprising the following steps:

[0008] Step 1: shaping silicon carbide particles: putting silicon carbide micropowder and silicon carbide ceramic balls into a ball mill for grinding, and then shaping them to obtain silicon carbide powder;

[0009] Step 2: Mechanical mixing: Calculate the volume fraction of silicon carbide particles to obtain the addition ratio of silicon carbide to aluminum; Add the shaped silicon carbide powder and aluminum powder into a mixer according to the required addition ratio, and perform mechanical mixing to obtain a mixed powder;

[0010] Step 3: Packaging: Put the mixed powder into an aluminum sleeve, vibrate it, seal the aluminum sleeve by argon arc welding, and weld the exhaust pipe at the sealing port;

[0011] Step 4: Vacuum thermal degassing: Place the sealed and welded aluminum sheath in a resistance furnace for heating, and use a vacuum exhaust device to degas the inside of the aluminum sheath through an exhaust pipe, and then press and seal the exhaust pipe to obtain a powder ingot containing the aluminum sheath;

[0012] Step 5: Hot isostatic pressing: Place the vacuum degassed ingot into a hot isostatic press for hot isostatic pressing. Then, the ingot is machined to remove the aluminum sheath to obtain a high thermal conductivity silicon carbide particle reinforced aluminum-based composite material.

[0013] Furthermore, in step three, the diameter of the aluminum sheath is 200 mm-500 mm.

[0014] Furthermore, in step 4, the aluminum sheath is heated in a stepwise manner.

[0015] Furthermore, in step 4, the heating temperatures of the aluminum sheath at each stage are 100° C., 300° C. and 500° C. respectively.

[0016] Furthermore, in step 4, the vacuum degree in the aluminum package needs to reach the required value range in each temperature range.

[0017] Furthermore, the vacuum degree in the aluminum package ranges from 10 -3 pa-10 -4 pa.

[0018] Furthermore, in step five, the pressure of hot isostatic pressing ranges from 180 MPa to 250 MPa.

[0019] Furthermore, the temperature of hot isostatic pressing is 500°C-600°C.

[0020] Furthermore, the hot isostatic pressing time is 3h-6h.

[0021] Further, step one includes:

[0022] Step S11: shaping silicon carbide particles: loading silicon carbide powder and silicon carbide ceramic balls into a ball mill for grinding;

[0023] Step S12: Screening: The ground and shaped silicon carbide powder is screened to screen out silicon carbide particles with a qualified particle size;

[0024] Step S13: Purification: acid-washing or alkali-washing the sorted silicon carbide powder for purification;

[0025] Step S14: water washing: washing the purified silicon carbide powder with water, and controlling the pH value of the water washing to be within a preset range;

[0026] Step S15: Drying: After dehydrating the washed silicon carbide powder, drying is performed to obtain silicon carbide micropowder specially used for high thermal conductivity aluminum-based composite materials.

[0027] Further, in step S14, the preset range of the pH value is 6.5-7.5.

[0028] Further, step four includes:

[0029] Step S41: Vacuum thermal degassing: The sealed aluminum sheath is placed in a resistance furnace for heating, and a vacuum exhaust device is used to degas the inside of the aluminum sheath through an exhaust pipe; wherein the aluminum sheath is heated in a stepwise manner, the aluminum sheath is first heated to 100°C and kept warm until the vacuum degree reaches 10 -3 pa-10 -4 pa, and then heated to 300℃.

[0030] Step S42: The aluminum jacket is kept at 300°C until the vacuum degree reaches 10 -3 pa-10 -4 pa, and then heated to 500℃.

[0031] Step S43: The aluminum jacket is kept at 500°C until the vacuum degree reaches 10-3 pa-10 -4 pa, and then press the exhaust pipe tightly and seal it.

[0032] Compared with the prior art, the method for preparing a high thermal conductivity silicon carbide particle reinforced aluminum-based composite material described in the present invention has the following beneficial effects:

[0033] The method can optimize the preparation process of high thermal conductivity aluminum-based composite materials, improve the morphology of SiC particles, reduce the specific surface area of ​​particles, reduce the bonding interface area of ​​composite materials, reduce the number of Al4C3 phases generated at the interface, and reduce the thermal resistance of the composite materials; improve the thermal conductivity of the composite materials; in addition, after shaping, the stress concentration caused by the sharp corners of the particles is eliminated, and the stress around the silicon carbide particles can be made more uniform and the mechanical properties can be better. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings, which constitute part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations of the present invention.

[0035] In the figure:

[0036] Figure 1 It is a schematic diagram of the process flow chart of the preparation method;

[0037] Figure 2 Schematic diagram of the SEM image of the morphology of silicon carbide particles before shaping;

[0038] Figure 3 Schematic diagram of the SEM image of the morphology of silicon carbide particles after shaping. DETAILED DESCRIPTION

[0039] The inventive concepts of the present disclosure will be described below using terms commonly used by those skilled in the art to convey the essence of their work to other persons skilled in the art. However, these inventive concepts can be embodied in many different forms and should not be considered limited to the embodiments described herein.

[0040] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0041] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0042] In order to solve the problem that the SiC particles used in the existing high thermal conductivity aluminum-based composite materials in the prior art are mostly obtained by artificial synthesis and then mechanical crushing, and the SiC particles are mostly cleaved and fractured along different crystal planes during the crushing process, so they are irregular in shape, and the particles have a high specific surface area, which increases the interface area of ​​the composite material and significantly reduces its thermal conductivity; this embodiment provides a method for preparing a high thermal conductivity silicon carbide particle reinforced aluminum-based composite material, and the method comprises the following steps:

[0043] Step 1: shaping silicon carbide particles: putting silicon carbide micropowder and silicon carbide ceramic balls into a ball mill for grinding, and then shaping them to obtain silicon carbide powder;

[0044] Step 2: Mechanical mixing: Calculate the volume fraction of silicon carbide particles to obtain the addition ratio of silicon carbide to aluminum; Add the shaped silicon carbide powder and aluminum powder into a mixer according to the required addition ratio, and perform mechanical mixing to obtain a mixed powder;

[0045] Step 3: Packaging: Put the mixed powder into an aluminum sleeve, vibrate it, seal the aluminum sleeve by argon arc welding, and weld the exhaust pipe at the sealing port;

[0046] Step 4: Vacuum thermal degassing: Place the sealed and welded aluminum sheath in a resistance furnace for heating, and use a vacuum exhaust device to degas the inside of the aluminum sheath through a vacuum pipe, then press and seal the vacuum pipe to obtain a powder ingot containing the aluminum sheath.

[0047] Step 5: Hot isostatic pressing: Place the vacuum degassed ingot into a hot isostatic press for hot isostatic pressing. Then, the ingot is machined to remove the aluminum sheath to obtain a high thermal conductivity silicon carbide particle reinforced aluminum-based composite material.

[0048] Among them, in step three, the diameter of the aluminum sleeve is 200mm-500mm. During the compaction process, the density of the mixed powder at each position in the aluminum sleeve needs to be kept similar. In step four, the aluminum sleeve is heated by step heating. The temperature sections of the step heating are 100℃, 300℃ and 500℃ respectively. In step four, the vacuum degree in the aluminum sleeve needs to reach the required value range in each temperature section. In step four, during the degassing process of the vacuum exhaust equipment, the vacuum degree in the aluminum sleeve is in the range of 10 - 3 pa-10 -4 In step 5, the pressure of hot isostatic pressing is in the range of 180Mpa-250Mpa; the temperature of hot isostatic pressing is in the range of 500°C-600°C; and the time of hot isostatic pressing is in the range of 3h-6h.

[0049] Compared with the traditional thermal management material using unshaped silicon carbide as reinforcement, the present invention uses shaped silicon carbide particles as reinforcement and then adopts powder metallurgy technology to prepare a method for preparing a high thermal conductivity aluminum-based composite material, which can optimize the preparation process of the high thermal conductivity aluminum-based composite material, improve the morphology of SiC particles, reduce the specific surface area of ​​particles, reduce the bonding interface area of ​​the composite material, reduce the number of Al4C3 phases generated at the interface, reduce the thermal resistance of the composite material; improve the thermal conductivity of the composite material; in addition, after shaping, the stress concentration caused by the sharp corners in the particles is eliminated, and the stress around the silicon carbide particles can be more uniform and the mechanical properties can be better. It is thus conducive to application in the field of electronic packaging.

[0050] Step one includes:

[0051] Step S11: shaping silicon carbide particles: loading silicon carbide powder and silicon carbide ceramic balls into a ball mill for grinding;

[0052] Step S12: Screening: The ground and shaped silicon carbide powder is screened to screen out silicon carbide particles with a qualified particle size;

[0053] Step S13: Purification: acid-washing or alkali-washing the sorted silicon carbide powder for purification;

[0054] Step S14: water washing: washing the purified silicon carbide powder with water, and controlling the pH value of the water washing to be within a preset range;

[0055] Step S15: Drying: After dehydrating the washed silicon carbide powder, drying is performed to obtain silicon carbide micropowder for high thermal conductivity aluminum-based composite materials with a regular and smooth surface.

[0056] Wherein, in step S14, the preset range of pH value is 6.5-7.5.

[0057] By shaping the irregularly shaped silicon carbide particles through the ball milling process in step one, the sharp edges and corners of the silicon carbide particles can be reduced, so that the silicon carbide particles have a regular structure, and the silicon carbide particles after shaping have a lower specific surface area, and the total interface area of ​​the composite material can be reduced, and the number of Al4C3 phases generated at the interface can be reduced, thereby reducing the thermal resistance caused by the composite interface, and making the composite material have a higher thermal conductivity. It is also possible to eliminate the stress concentration caused by the sharp corners in the silicon carbide particles, so that the stress distribution around the silicon carbide particles is more uniform and the mechanical properties are better. In addition, by controlling the pH value of the water wash, it is helpful to avoid excessive shaping of silicon carbide and improve the stability of silicon carbide during shaping.

[0058] Step 4 includes:

[0059] Step S41: Vacuum thermal degassing: The sealed aluminum sheath is placed in a resistance furnace for heating, and a vacuum exhaust device is used to degas the inside of the aluminum sheath through an exhaust pipe; wherein the aluminum sheath is heated in a stepwise manner, the aluminum sheath is first heated to 100°C and kept warm until the vacuum degree reaches 10 -3 pa-10 -4 pa, and then heated to 300℃.

[0060] Step S42: The aluminum jacket is kept at 300°C until the vacuum degree reaches 10 -3 pa-10 -4 pa, and then heated to 500℃.

[0061] Step S43: The aluminum jacket is kept at 500°C until the vacuum degree reaches 10 -3 pa-10 -4 pa, and then press the exhaust pipe tightly and seal it.

[0062] In step S41, whether the exhaust of the aluminum jacket meets the requirements is determined by whether the vacuum degree in the aluminum jacket is within the required vacuum degree range. Whether the heating of the aluminum jacket meets the requirements is determined by whether the temperature in the resistance furnace reaches the required temperature value.

[0063] By using a step-by-step heating method to degas the ingot during vacuum thermal degassing, it is possible to effectively prevent the volatile products from reacting with the composite material in the aluminum sheath during the heating process of the ingot, reduce the influence of impurities inside the composite material on the density and thermal conductivity of the composite material ingot, and effectively improve the thermal conductivity of the silicon carbide reinforced aluminum-based composite material.

[0064] Embodiment 1:

[0065] Step 1: put silicon carbide powder with a purity of ≥99.5% and a D50 of 15-20 μm and silicon carbide ceramic balls with a diameter of 2-5 mm into a ball mill at a ball-to-material ratio of 1:1 for ball milling, adjust the ball mill rotation speed to 600-900 r / min, the revolution speed to 300-400 r / min, and the ball milling time to 12-24 h;

[0066] The ball-milled silicon carbide powder is sieved with a 1800-mesh sieve to sieve out silicon carbide particles with a particle size of more than 10 μm;

[0067] Add sulfuric acid to the sorted silicon carbide powder for pickling and purification, the amount of sulfuric acid added is 5%-10% of the total weight of the powder, and filter after purification for 2 hours;

[0068] The purified silicon carbide powder is washed with deionized water until the pH value of the cleaning solution is between 6.5 and 7.5;

[0069] After the washing, the powder is dehydrated and placed in a drying oven for drying at a temperature of 150-200°C for 1-3 hours.

[0070] Step 2: Add the dried silicon carbide powder and pure aluminum powder into a mixer for mechanical mixing, the volume fraction of silicon carbide is 45%, and the mixing time is 8h-24h;

[0071] Step 3: Put the evenly mixed powder into a pure aluminum bag and vibrate it to make the powder density at each position similar. The diameter of the bag is 180mm and the height is 300mm.

[0072] The aluminum sheath is sealed by argon arc welding, and the exhaust pipe is welded at the sealing cover;

[0073] Step 4: Place the powder ingot sealed by the aluminum package into the heating furnace, and connect the vacuum pumping equipment to the vacuum pipe. The heating temperature is 100°C. Vacuum is pumped while heating until the vacuum degree in the aluminum package reaches 1-2×10 -3 pa, then raise the temperature to 300℃ and continue to evacuate to 1~2×10 -3 pa, then raise the temperature to 500℃ and continue to evacuate to 1~2×10 - 3 Pa;

[0074] After the vacuum heat degassing is completed, the exhaust pipe is sealed to prevent air leakage from the package;

[0075] Step 5: The ingot after hot degassing is placed in a hot isostatic press at a temperature of 510°C and a pressure of 150MPa for 4 hours;

[0076] The ingot after hot isostatic pressing is machined to remove the outer aluminum sheath to obtain a high thermal conductivity silicon carbide reinforced aluminum matrix composite material.

[0077] Comparative Example 1:

[0078] The difference from Example 1 is that an unshaped SiC / Al composite material is used for preparation to obtain an aluminum-based composite material. The composite materials prepared in Comparative Example 1 and Example 1 are tested to obtain relevant performance data of the two composite materials, as shown in Table 1.

[0079] Table 1

[0080] Process route Thermal conductivity (W / (m·K)) Flexural strength(MPa) Unshaped SiC / Al composites 185 408 SiC / Al composite material after shaping 199 468

[0081] It can be seen from the data in Table 1 that the thermal conductivity of the composite material after shaping is increased by about 8% compared with the thermal conductivity of the unshaped composite material, and the flexural strength of the composite material after shaping is increased by about 15% compared with the flexural strength of the unshaped composite material. From the test results, it can be seen that the various properties of the composite material after shaping are significantly improved, which can more effectively reduce the thermal resistance of the composite material, improve the thermal conductivity of the composite material, and achieve the improvement of the mechanical properties of the composite material.

[0082] Embodiment 2:

[0083] Step 1: put silicon carbide powder with a purity of ≥99.5% and a D50 of 50-55 μm and silicon carbide ceramic balls with a diameter of 5-10 mm into a ball mill at a ball-to-material ratio of 1:1 for ball milling, adjust the ball mill rotation speed to 600-900 r / min, the revolution speed to 300-400 r / min, and the ball milling time to 12-24 h;

[0084] The ball-milled silicon carbide powder is sieved with a 500-mesh sieve to sieve out silicon carbide particles with a particle size of more than 30 μm;

[0085] The sorted silicon carbide powder is added to nitric acid for pickling and purification. The concentration of nitric acid is 4 mol / L. After purification for 5 hours, it is filtered;

[0086] The purified silicon carbide powder is washed with deionized water until the pH value of the cleaning solution is between 6.5 and 7.5;

[0087] After the washing, the powder is dehydrated and placed in a drying oven for drying at a temperature of 150-200°C for 1-3 hours.

[0088] Step 2: Add the dried silicon carbide powder and pure aluminum powder into a mixer for mechanical mixing, the volume fraction of silicon carbide is 55%, and the mixing time is 8-24 hours;

[0089] Step 3: Put the evenly mixed powder into a pure aluminum bag and vibrate it to make the powder density at each position similar. The diameter of the bag is 300mm and the height is 500mm.

[0090] The aluminum sheath is sealed by argon arc welding, and the exhaust pipe is welded at the sealing cover;

[0091] Step 4: Place the powder ingot sealed by the aluminum package into the heating furnace, and connect the vacuum pumping equipment to the vacuum pipe. The heating temperature is 100°C. Vacuum is pumped while heating until the vacuum degree in the aluminum package reaches 1-2×10 -3 pa, then raise the temperature to 300℃ and continue to evacuate to 1~2×10 -3 pa, then raise the temperature to 500℃ and continue to evacuate to 1~2×10 -3 Pa;

[0092] After the vacuum heat degassing is completed, the exhaust pipe is sealed to prevent air leakage from the package;

[0093] Step 5: The ingot after hot degassing is placed in a hot isostatic press at a temperature of 540°C and a pressure of 140 MPa for 6 hours;

[0094] The ingot after hot isostatic pressing is machined to remove the outer aluminum sheath to obtain a high thermal conductivity silicon carbide reinforced aluminum matrix composite material.

[0095] Comparative Example 2:

[0096] The difference from Example 2 is that an unshaped SiC / Al composite material is used for preparation to obtain an aluminum-based composite material. The composite materials prepared in Comparative Example 2 and Example 2 were tested to obtain relevant performance data of the two composite materials, as shown in Table 2.

[0097] Table 2

[0098] Process route Thermal conductivity (W / (m·K)) Flexural strength(MPa) Unshaped SiC / Al composites 192 379 SiC / Al composite material after shaping 211 431

[0099] It can also be seen from the data in Table 2 that the thermal conductivity of the composite material after shaping is increased by about 10% compared with the thermal conductivity of the unshaped composite material, and the flexural strength of the composite material after shaping is increased by about 14% compared with the flexural strength of the unshaped composite material. From the test results, it can be seen that the various properties of the composite material after shaping can also be significantly improved, and it can also more effectively reduce the thermal resistance of the composite material, improve the thermal conductivity of the composite material, and achieve the improvement of the mechanical properties of the composite material.

[0100] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a high thermal conductivity silicon carbide particle reinforced aluminum-based composite material, characterized in that: The following steps are involved: Step 1: shaping silicon carbide particles: putting silicon carbide micropowder and silicon carbide ceramic balls into a ball mill for grinding, and then shaping them to obtain silicon carbide powder; Step 2: Mechanical mixing: Calculate the volume fraction of silicon carbide particles to obtain the addition ratio of silicon carbide to aluminum; Add the shaped silicon carbide powder and aluminum powder into a mixer according to the required addition ratio, and perform mechanical mixing to obtain a mixed powder; Step 3: Packaging: Put the mixed powder into an aluminum sleeve, vibrate it, seal the aluminum sleeve by argon arc welding, and weld the exhaust pipe at the sealing port; Step 4: Vacuum thermal degassing: Place the sealed and welded aluminum sheath in a resistance furnace for heating, and use a vacuum exhaust device to degas the inside of the aluminum sheath through an exhaust pipe, and then press and seal the exhaust pipe to obtain a powder ingot containing the aluminum sheath; Step 5: Hot isostatic pressing: Place the vacuum degassed ingot into a hot isostatic press for hot isostatic pressing. Then, the ingot is machined to remove the aluminum sheath to obtain a high thermal conductivity silicon carbide particle reinforced aluminum-based composite material.

2. The method for preparing a high thermal conductivity silicon carbide particle reinforced aluminum-based composite material according to claim 1, characterized in that: In the step three, the diameter of the aluminum sheath is 200mm-500mm.

3. The method for preparing a high thermal conductivity silicon carbide particle reinforced aluminum-based composite material according to claim 1, characterized in that: In the step 4, the aluminum sheath is heated by step-by-step heating.

4. The method for preparing a high thermal conductivity silicon carbide particle reinforced aluminum-based composite material according to claim 3, characterized in that: The temperature sections of the step-by-step heating are 100° C., 300° C. and 500° C. respectively.

5. The method for preparing a high thermal conductivity silicon carbide particle reinforced aluminum-based composite material according to claim 1, characterized in that: In the step 4, the vacuum degree in the aluminum package needs to reach the required value range in each temperature range.

6. The method for preparing a high thermal conductivity silicon carbide particle reinforced aluminum-based composite material according to claim 5, characterized in that: The vacuum degree in the aluminum package ranges from 10 -3 pa-10 -4 pa.

7. The method for preparing a high thermal conductivity silicon carbide particle reinforced aluminum-based composite material according to claim 1, characterized in that: In the step 5, the pressure of the hot isostatic pressing is in the range of 180 MPa-250 MPa.

8. The method for preparing a high thermal conductivity silicon carbide particle reinforced aluminum-based composite material according to claim 7, characterized in that: The temperature of the hot isostatic pressing is 500°C-600°C.

9. The method for preparing a high thermal conductivity silicon carbide particle reinforced aluminum-based composite material according to claim 7, characterized in that: The hot isostatic pressing time is 3h-6h.

10. The method for preparing a high thermal conductivity silicon carbide particle reinforced aluminum-based composite material according to claim 1, characterized in that: The step one comprises: Step S11: shaping silicon carbide particles: loading silicon carbide powder and silicon carbide ceramic balls into a ball mill for grinding; Step S12: Screening: The ground and shaped silicon carbide powder is screened to screen out silicon carbide particles with a qualified particle size; Step S13: Purification: acid-washing or alkali-washing the sorted silicon carbide powder for purification; Step S14: water washing: washing the purified silicon carbide powder with water, and controlling the pH value of the water washing to be within a preset range; Step S15: Drying: After dehydrating the washed silicon carbide powder, drying is performed to obtain silicon carbide micropowder specially used for high thermal conductivity aluminum-based composite materials.

11. The method for preparing a high thermal conductivity silicon carbide particle reinforced aluminum-based composite material according to claim 10, characterized in that: In step S14, the preset range of pH value is 6.5-7.

5.

12. The method for preparing a high thermal conductivity silicon carbide particle reinforced aluminum-based composite material according to claim 1, characterized in that: The fourth step comprises: Step S41: Vacuum thermal degassing: The sealed aluminum sheath is placed in a resistance furnace for heating, and a vacuum exhaust device is used to degas the inside of the aluminum sheath through an exhaust pipe; wherein the aluminum sheath is heated in a stepwise manner, the aluminum sheath is first heated to 100°C and kept warm until the vacuum degree reaches 10 -3 pa-10 -4 pa, then heated to 300°C; Step S42: The aluminum jacket is kept at 300°C until the vacuum degree reaches 10 -3 pa-10 -4 pa, then heated to 500°C; Step S43: The aluminum jacket is kept at 500°C until the vacuum degree reaches 10 -3 pa-10 -4 pa, and then press the exhaust pipe tightly and seal it.

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