Effect of tool rotation rate on constituent particles in a friction stir processed 2024Al alloy

Friction stir processing (FSP) carried out on a commercial AA2024Al alloy using different tool rotation rates (200-1000rpm) led to significant change in size and morphology of the constituent particles. The size of insoluble Al6(Cu,Mn,Fe) particles presentin the stir zone was substantially reduced as a function of tool rotation rate whereas smaller soluble Al-Cu-Mg based particles exhibited significant reduction in amount only at higher tool rotation rates. Severe plastic deformation, peak temperature and constituent particle characteristics influenced their evolution.