“…This suggests there will be an inhomogeneity across the disk but, by contrast, many results show that this inhomogeneity gradually disappears with increasing deformation. For example, there is a gradual evolution towards microhardness homogeneity in numerous metallic alloys such as Al-4wt.%Mg, [31] AZ31, [32] Al-6063 and Cu-0.1% Zr. [33,34] A detailed review is now available summarizing these trends for a large number of metals.…”