Electrochemical and XPS studies of a Nb-containing Ti-based glass-forming alloy system in H2SO4 solution

The corrosion behaviors of Ti40Zr25Ni12 -xNbxCu3Be20 (x = 0, 4, 8, and 12 at.%) alloys in 0.5 mol/L H2SO4 solution were studied, aiming to establish the relationship between Nb content and corrosion resistance. The addition of Nb element gives rise to a clear microstructural evolution, from a completely amorphous structure for the alloys without Nb and with 4% Nb alloys to an amorphous/crystalline composite structure for the alloys with 8% and 12% Nb. The alloy with higher Nb content exhibits better corrosion resistance, which can be attributed to the formation of Ti4 +-, Zr4 +-, and Nb5 +-enriched highly protective surface film in corrosive solutions.