A novel rare earth-salt bath nitriding of TC21-DT titanium alloy

摘要

A novel rare earth (RE)-salt bath nitriding of TC21-DT titanium alloy was primarily developed by adding certain amount of RE cerium oxide (CeO2) in KNO3 and NaNO3 salt bath, heated to temperatures in the range 590-650 degrees C for periods up to 5 h in an ambient furnace atmosphere. The results showed that Ti phases and titanium nitride phase were formed on the surface of RE added samples; while no titanium nitride phases formed on the surface of conventional one, without RE addition. Furthermore, the surface hardness of nitrided samples, incorporated with RE addition, was about two times higher than that of conventional one (340HV(0.01)). The main improvement mechanism was analysed as well.