Microstructural characterization of Molybdenum particle reinforced aluminium surface composites fabricated by friction stir processing

Friction stir processing is used to fabricate aluminium matrix surface composites with better interfacial bonding between the matrix and reinforcement particles. Metallic Mo particle is used as the reinforcement. The study on aluminium matrix surface composites with metallic Mo reinforcement fabricated by FSP groove method shows improved surface properties such as hardness, and corrosion resistance compared to the unprocessed base material. Microstructural characterization, reinforcement size and distribution, and the corresponding hardness behavior of surface composites fabricated by friction stir processing are analyzed. The particle size distribution before and after the processing is analyzed to understand the mechanical shearing of reinforcement particles. Grain refinement due to the plastic deformation during FSP and the distribution of finer Mo particles enhanced the surface hardness of the composites. Surface composites exhibit a two-fold increase in the surface hardness compared to the unprocessed base material. Knowledge about the effect of friction stir processing and Mo particles on the surface properties will enable the development of composite materials with enhanced surface properties with better interfacial bonding between the matrix and the reinforcement particles.