Metastable pitting corrosion behavior of laser powder bed fusion produced Ti6Al4V-Cu in 3.5% NaCl solution

Laser powder bed fusion (LPBF) technology realized the surgical personalized devices. However, LPBF-produced titanium alloys face several limitations, such as obvious metastable pits. This work presented a promising strategy to enhance the corrosion resistance of LPBF-produced Ti6Al4V alloy by the Cu alloying. Compared to the Ti6Al4V alloy, Ti6Al4V-Cu alloy possessed a more protective passive film with stable oxides due to its finer grains. Furthermore, Ti6Al4V-Cu alloy demonstrated superior metastable pitting corrosion resistance in a 3.5 wt% NaCl solution, because Cu substituents effectively consumed the cationic vacancies in the passive film, thus inhibited the nucleation of the metastable pits.