Effect of particle surface treatment on the microstructure and property of SiCp/AA6066 composite produced by powder metallurgy

Three different kinds of surface modification techniques were introduced into the preparation of SiCp/AA6066 composites fabricated by powder metallurgy route (PM). The microstructures were investigated by optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and the mechanical properties were measured by dynamic mechanical analyzer (DMA) and tensile testing. The mechanical properties of the composites were improved by using oxidized and acid pickled SiC particles and further heightened by using oxidized, acid pickled and alkali treated SiC particles due to the thin and strongly bonded SiC/Al interfaces. However, the mechanical properties of the composites reinforced by SiC particles coated with potassium fluozirconate sharply decreased due to the thick and weakly bonded SiC/Al interfaces. The different particle surfaces resulted in differences in the SiC/Al interfaces and the mechanical properties of the composites.