Microstructural Characterization and Tensile Behavior of Rutile (TiO ₂ )-Reinforced AA6063 Aluminum Matrix Composites Prepared by Friction Stir Processing

Rutile (TiO ₂ ) particle-reinforced aluminum matrix composites were prepared by friction stir processing. The microstructure was studied using conventional and advanced characterization techniques. TiO ₂ particles were found to be dispersed uniformly in the composite. Clusters of TiO ₂ particles were observed at a higher particle content of 18 vol%. The interface between the TiO ₂ 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. TiO ₂ 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.