Characterization of NbC-Reinforced AA7075 Alloy Composites Produced Using Friction Stir Processing

Aluminium alloy AA7075 matrix composites reinforced with varying vol% (5, 10 and 15 vol%) of niobium carbide (NbC) were fabricated by friction stir processing. Micrographs revealed that a homogeneous dispersion of NbC in the AA7075 matrix had no interfacial reaction. Significant degree of grain refinement was observed in the composites due to dynamic recrystallization and pinning effect of NbC particles. Hardness and tensile strength of AA7075 matrix were found to be enhanced by the addition of NbC particles. The fracture surface of the tensile-tested samples revealed deep dimples indicating a good ductility.