Configuration Optimization And Thermal Conductivity Study Of Diamond-SiC/Al Matrix Composites

With the development of electronic information technology,the heat generation of electronic devices has increased significantly.Thermal management issues have become a key factor restricting the development of related industries.The research and development of new thermal management materials is urgent.Based on the application requirements of high thermal conductivity,light weight and low cost of thermal management materials in the 5G era,diamond-Si C/Al composite materials which combined with the advantages and disadvantages of different thermal management materials was designed.The mechanism of composite material configuration on thermal conductivity was revealed by exploring the influence of particle configuration and three-dimensional foam configuration on thermal conductivity.The main research contents and conclusions are as follows:(1)For the particle-enhanced diamond-Si C/Al composite materials,the preform were prepared through the compression molding technology and the composite configuration was controlled by changing the volume ratio and particle size ratio.Diamond-Si C/Al composite materials were prepared by gas pressure infiltration technology.The results showed that the thermal conductivity of composites improved with the increase of diamond volume fraction when the particle size ratio remains unchanged.The thermal conductivity of the composite containing F100 Si C and 30 vol.% of diamond was the best and its thermal conductivity was 344W/(m·K).Under the condition that the volume ratio of diamond keeped constant,the increase of the particle size ratio of Si C and diamond was beneficial to improve thermal conductivity of diamond-Si C/Al composite materials.When the particle size ratio of the composite with 15 vol.% of diamond increased from 0.07 to 0.65,the thermal conductivity increased from 174 W/(m·K)to 274 W/(m·K)increasing by 57%.(2)For the three-dimensional foam-enhanced diamond-Si C/Al composite material,chemical vapor deposition technology was used to deposit a dense and uniform high-quality diamond film on the foamed Si C substrate.W coating on the surface of foamed diamond was prepared by hot filament vacuum evaporation technology.Vacuum gas infiltration technology was used to prepare the composite of reinforcement and Al matrix.The results showed that the Al matrix distributed in the pores of the foam reinforcement forming a double interpenetrating three-dimensional network structure with the reinforcement,which realized the construction of efficient heat conduction channels.When the diamond volume fraction was only 5.2%,the thermal response speed of the three-dimensional foamreinforced diamond-Si C/Al composite was close to Cu.Its thermal conductivity was 201 W/(m·K)and its thermal conductivity enhancement efficiency was 3.7 times larger than particle-enhanced diamond-Si C/Al.