Abstract: SiC reinforced aluminum matrix composites are widely used in aerospace, electronic packaging and transportation due to their high specific strength, high thermal conductivity and high wear resistance. In this paper, SiC particle reinforced aluminum matrix composites were prepared by hot pressing sintering. The effects of SiC content on the microstructure and mechanical properties of aluminum matrix composites were studied. The phase composition, apparent density and mechanical properties of the samples were determined by X-ray diffraction, Archimedes drainage method, Rockwell hardness analysis and three-point bending method. The microstructure of the samples was analyzed by SEM. The thermal conductivity was measured by laser flash method. The results show that the hardness of the samples increases first and then decreases with the increase of the volume fraction of SiC particles from 0% to 60%, and reaches the maximum value of 90 HRB when the volume fraction of SiC is 50%. The thermal conductivity of the samples increases first and then decreases, and reaches the maximum value of 324.05 W/(m·K) when the volume fraction of SiC is 30%. With the increase of SiC volume fraction, the metal matrix and the reinforcement are closely combined without obvious pores. When the volume fraction of SiC increases to 60%, the porosity of the samples increases, the consistency decreases, and the strength decreases.

Key words: SiC_p/Al composite, SiC content, apparent density, hardness, thermal conductivity