The development of hardness homogeneity in pure aluminum and aluminum alloy disks processed by high-pressure torsion

? The Vickers microhardness distributions were measured on four different materials processed by high-pressure torsion. ? The hardness is initially high in the centers of the HPT disks of high-purity aluminum. ? The hardness is initially low in the centers of the disks for the other three materials. ? The hardness achieves saturation values after 5 turns in high-purity Al and the commercial purity Al. ? More torsional strain is required to achieve homogeneity in the other two alloys.This work was supported by the National Science Foundation of the United States under grant no. DMR-0855009