Using X-ray microdiffraction to determine grain sizes at selected positions in disks processed by high-pressure torsion

Disks of pure Cu, Cu–10% Zn and Cu–30% Zn were processed by high-pressure torsion (HPT) and then examined at selected positions using microhardness testing and X-ray microdiffraction line broadening. The results show excellent agreement between the microhardness measurements and X-ray microdiffraction. The grain sizes and the microhardness values are essentially constant across the diameters of the disks of pure Cu and the Cu–30% Zn alloy but for the Cu–10% Zn alloy the measured grain size is largest and the hardness is lowest in the center of the disk. The results demonstrate the potential for achieving a reasonably homogeneous microstructure in samples processed by HPT.