the influence of the applied pressure on the microhardness was investigated for Ni disks subjected to a certain torsional strain of 5 revolutions under different pressures . the experiments reported that the microhardness values are non-uniform across the diameter where there are lower hardness values in the center of the disk. however, an increase in the applied pressure from 1.0-9.0 GPa leads to an overall increase in hardness, especially in the centers of the disks so that at a pressure of 9.0 GPa there is a reasonably homogeneous distribution of hardness.