High Temperature Anti-Oxidation Behavior and Anti-Oxidation Mechanism of Arc-Sprayed Aluminum Coating on Titanium Substrate

Aluminum coating was prepared on the surface of titanium substrate by arc spraying in order to improve the high temperature anti-oxidation behavior of titanium substrate.As-obtained Al coating was continuously oxidized at 800 ℃ for64 h,and its anti-oxidation mechanism at elevated temperature was explored in relation to the changes in its microstructure upon oxidation.Results showed that the are-sprayed Al coating could significantly improve the high-temperature oxidation resistance of titanium substrate.The are-sprayed Al coating underwent melting and diffusion during the heating process to form a diffusion layer consisting of Al_3Ti as the major phase.The Al-rich Al_3Ti phase could provide sufficient Al element to form a continuous layer of Al_2O_3 on the coating surface,thereby providing effective protection for the pure titanium substrate at high temperature.