Electron backscatter diffraction (EBSD) microstructure evolution in HPT copper annealed at a low temperature

Detailed EBSD analysis was performed on copper specimens processed by high-pressure torsion at P = 6 GPa for one whole turn and subsequently annealed at a temperature of 100 °C for 15, 30 and 60 min. The basic microstructural parameters (mean grain size, GB statistics, microtexture) were evaluated in the mid-radius areas of the HPT disks. Microhardness of all samples was measured across the two diameters and interlinked to the microstructures observed. Small but noticeable changes of microhardness in HPT copper after annealing were detected. The changes were interlinked to microstructural parameters acquired by EBSD. The relationships obtained are discussed in terms of the microstructure and microtexture evolution during low temperature annealing.