Post-shear deformation of high pressure torsion-deformed nickel under hydrostatic pressure

In order to study the deformation mechanism of severe plastic deformed metals at very high strains, high pressure torsion experiments were performed. Backscatter electron images were used to characterize the change in microstructure after the shear deformation. Post-shear deformation of such samples under hydrostatic pressure revealed that the microstructure is sheared homogeneously, although some regions were found where microshear bands had formed. Grain boundary sliding at this very high strain was not observed during the experiment.