The effect of cryogenic burnishing on the formation mechanism of corrosion product film of Ti-6Al-4V titanium alloy in 0.9% NaCl solution

Effect of cryogenic burnishing on the corrosion product film formation mechanism of Ti-6Al-4V titanium alloy has been investigated in this work. The corrosion product films of both burnished and unburnished specimens exhibited three distinct oxide layers. Compared with un-burnished specimens, burnished specimens possessed a thicker subsurface layer with high-valent oxides and additional Al₂O₃ in the inner layer. The chemical activity, diffusion, and distribution of alloy elements were changed by high-density dislocations, nano-grains, twins and compressive residual stress induced by cryogenic burnishing, resulting in the enhancement of the compactness, thickness, growth rate and protection of corrosion product film on the Ti-6Al-4V alloy.