Adiabatic shear localization induced by rotationally accelerated shot peening

Rotationally accelerated shot peening imposes high strain rates and strain accumulation on the surface of a pure nickel. As a result, a gradient structure is developed from the surface to the interior of the bulk sample. In addition to dislocation activities and deformation twinning, shear band is activated to accommodate localized shear strains at the outmost surface. A high density of defects accumulated during the strain hardening process is a prerequisite for the shear banding deformation. The orientation relationship between the deformed matrix and the shear bands, and thermally assisted mechanical rotation of nanograins occurred during partial dynamic recrystallization, together reveal the adiabatic nature of shear localization.