Effect of stress-relief annealing on anodic dissolution behaviour of additive manufactured Ti-6Al-4V via laser solid forming

Stress-relief annealing is one of the most frequently used heat treatments for additive manufactured components. The effects of the stress-relief annealing on anodic dissolution behaviour of laser solid formed Ti-6Al-4V in a 15wt.% NaCl electrolyte was investigated. The annealed Ti-6Al-4V exhibited comparatively improved resistance to dissolution compared with as-deposited one. The reduced micro-segregation resulted in the superior corrosion resistance for the annealed Ti-6Al-4V, owing to the formation of a more stable passive film and the weakened galvanic effect. The selective dissolution of α phase was lightened with the decreasing concentration difference of solutes between the refined α and β phases.