Effect of friction stir processing on the microstructure and mechanical properties of Cu-TiC composite

In this research, a Copper-based composite was fabricated by TiC reinforcement via friction stir processing. Holes with the diameter and depth of 2 mm were made on the surface of a pure copper specimen and filled by TiC powders. Friction srir processing was carried out with transverse and rotational speeds of 50 mm/min and 1000 rpm, respectively. Optical and scanning electron microscope observations revealed that FSP produced a fine grain microstructure with a homogeneous distribution of particles on the surface. Reinforcing particles showed a good bonding with the base metal. Mechanical test results also proved that FSP increased the microhardness and the wear resistance of specimen as a result of grain refinement and the existence of TiC particles in the FSP zone. Maximum hardness in the stir zone was 117 Vickers, while the hardness of pure copper was 65 Vickers. X-Ray analysis proved no intermetallic compounds in the stir zone.