Wear behaviour of a Mg alloy subjected to friction stir processing

► Mg alloy AE42 friction stir processed (FSPed) under optimized conditions. ► FSPed alloy characterized by presence of sub-micron and equiaxed grain structure. ► Wear behaviour of as-cast and FSPed alloy evaluated under dry sliding conditions. ► FSPed alloy demonstrated significant reduction in the wear rates. ► Lower wear rate of FSPed alloy attributed to the microstructural refinement.