Corrosion and passivation behavior of laser powder bed fusion produced Ti-6Al-4V under various prior plastic deformation strains

This work investigated the corrosion behavior of LPBF-produced Ti-6Al-4V under varying compression strains in a 3.5 wt% NaCl solution. It identifies that increasing compression strain causes significant alterations in the acicular alpha'-Ti phase (coarsening, breakage, and further coarsening). Corrosion resistance decreases with higher strains due to deformed alpha'-Ti phases, leading to increased film growth kinetics (from 0.09x 10-10 cm2/s increase to 12.75 x 10-10 cm2/s). Samples under higher strains (e.g., 32%) exhibit fluctuations in corrosion behavior due to initiated cracks and subsequent crevice corrosion. These findings are vital for understanding LPBF-produced Ti-6Al-4V in applications requiring mechanical strength and corrosion resilience.