Effect of rotational speed and probe profile on microstructure and hardness of AZ31/Al2O3 nanocomposites fabricated by friction stir processing

► Friction stir processing (FSP) can be used as a nanocomposite fabrication process. ► Grain refinement of matrix of the composite is obtained after each FSP pass. ► Distribution of nanoparticles is improved after each FSP pass. ► Grain growth of matrix is enhanced by increase of rotation speed.