Investigation of Microstructure and Wear Resistance of AZ31-SiO2 Surface Nanocomposite by Friction Stir Processing

As magnesium and its alloys are almost 35% lighter than aluminum alloys, they are ideal candidates for automotive and aerospace industries. In this research, multipass friction stir processing (FSP) was used to produce Mg-based surface nanocomposite with SiO2 particles. Microstructure features such as grain size and particle distribution were investigated. The reactions between magnesium and nanoparticles and the relation between microstructure and hardness, wear resistance, and corrosion behaviour were also studies. The mean grain size of the composite after four passes reduced by 82%, its hardness increased by 29%, and its wear resistance increased more than 34.6% compared with Mg-base alloy. Furthermore, this composite had the best corrosion resistance as a result of fine grain size.