Microstructure-microhardness relation of nanostructured Ni produced by high-pressure torsion

X-ray diffraction line broadening, TEM and microhardness investigations were carried out on Ni samples produced by the high-pressure torsion (HPT) technique. Distribution of grain size, microstrain (dislocation density) along the radial direction of the as-pressed Ni disk were quantified. Gradient in microhardness from the center to the edge of the deformed Ni disk is rationalized in terms of the grain size, dislocation density and grain boundaries at the corresponding region.