Corrosion resistance research of laser additive manufactured TC11 titanium alloy

The corrosion resistance of laser additive manufactured (LAM) TC11 titanium alloy is studied in hydrochloric acidic solution with immersion and electrochemical corrosion test methods. Surface morphologies are analyzed by scanning electron microscope. The results indicate that α phase of laser additive manufactured TC11 titanium alloy contains low-content Mo element, and easily selective dissolves preferentially. In hydrochloric acidic solution, with the extending corrosion time, the open circuit potential first decreases and then increases gradually, and the charge transfer resistance R_ct sharply decreases before maintaining stability. Self-corrosion current density i_corr increases with the increase of the corrosion time. The α+ β basket-weave microstructure of laser additive manufactured TC11 titanium alloy possesses finer α phase than that of bimodal microstructure of forged alloy, and exhibits better corrosion resistance. Microstructure of the heat-treated specimen contains higher volume fraction and coarsening α-phase, but a slight decrease in the corrosion resistance.