Microstructural evolution and its effects on mechanical properties of spray deposited SiCp/8009Al composites during secondary processing

15% (volume fraction) SiCp/8009Al metal matrix composites(MMCs) prepared by spray co-deposition were hot-extruded and rolled to investigate the effects of porosity and local SiCp clusters on mechanical properties. The microstructures were examined by using optical microscopy(OM), scanning electron microscopy(SEM), X-ray diffractometry(XRD) and transmission electron microscopy(TEM). The mechanical properties were measured by tensile testing. The experimental results show that lamellar structure is composed of pores and SiCp clusters and can be improved by secondary processing, enhancing mechanical properties. The main strengthening mechanism and fracture behavior of MMCs were discussed too.