Abstract: Influence of different content of Cu addition on microstructure and properties of the SiC_p/Al-Si composites prepared by powder metallurgy was studied by means of X-ray diffraction, scanning electron microscopy, precision electronic balance and universal testing machine. The results show that the addition of Cu element leads that the density, hardness, tensile strength, friction and wear resistance of the material are improved greatly, and the strength reaches the maximum when the Cu content is 4% (mass fraction). Since the Cu element is added in the form of copper powder in the matrix, a liquid phase can be formed through mutual diffusion at the Al-Cu boundary even at a lower temperature, thereby filling the gaps, holes and other defects in the matrix and at the interface. During rapid cooling of the green compact to room temperature, α-Al and Al₂Cu phases are produced and both have strengthening effect on material, which improves the comprehensive mechanical properties of the SiC_p/Al-Si composites.

Key words: SiC_p/Al-Si composites, Cu element, SiC particles, microstructure, mechanical properties