Microstructure and Mechanical Property of SiC Reinforced 7075 Alloy Surface Composite Fabricated by Friction Stir Processing

In this study, friction stir processing (FSP) has been used to prepare aluminum-base composite with addition of SiC reinforcement particles. Aluminum alloy 7075 surface composite has been successfully fabricated at a suitable ratio of tool rotation rate/traverse speed by one-pass FSP. SiC particles were distributed almost homogeneously over the nugget zone, and strong interfacial adhesion was obtained between SiC particles and 7075 alloy matrix. The existence of reinforcement particles caused the enhancement of microhardness and impact toughness over the nugget zone compared to 7075 alloy matrix. The impact fracture of composite layer was characterized by aluminum alloy matrix toughness tear and SiC particle brittle rupture.