Ion irradiation effects on the mechanical behavior of vanadium micropillars

The present work reports the impact of proton irradiation on the mechanical behavior of vanadium micropillars with various diameters at room temperature. Irradiation induced strengthening appears more significant with increasing pillar size, and the critical diameter to reach size-independent strength is strongly reduced after irradiation to 0.2 dpa. Although all unirradiated pillars deform uniformly, the deformations of the irradiated pillars thicker than 1 μm are concentrated within the top 30 % region, where most irradiation defects are wiped by deformation dislocations, leading to softening and the consequent unique deformation localization behavior.