Microstructural Characterization and Tensile Behavior of Rutile (TiO2)-Reinforced AA6063 Aluminum Matrix Composites Prepared by Friction Stir Processing

Rutile (TiO2) particle-reinforced aluminum matrix composites were prepared by friction stir processing. The microstructure was studied using conventional and advanced characterization techniques. TiO2 particles were found to be dispersed uniformly in the composite. Clusters of TiO2 particles were observed at a higher particle content of 18 vol%. The interface between the TiO2 particle and the aluminum matrix was characterized by the absence of pores and reactive layer. Sub-grain boundaries, ultra-fine grains and dislocation density were observed in the composites. TiO2 particles improved the mechanical properties of the composites. However, a drop in tensile strength was observed at a higher particle content due to cluster formation. All the prepared composites exhibited ductile mode of fracture.