Commercially pure Cu plates were friction stir welded with SiC powders. The microstructure can be refined by the addition of SiC powders, which acted as the nucleation site for the recrystallized Cu grains. No reactions between the copper and the SiC particles were detected. For 1 pass FSWed sample, hardness increased but with hardness drops in some localized areas. While hardness profile become uniform after 2 pass due to the homogenous distribution of SiC powders.
