Research on Oxidation Behavior of CP Titanium TA2

Oxidation behavior of commercial titanium TA2 was investigated at various atmosphere temperatures ranging from 650℃ to 1 000℃.The results show that oxidation rate was low at temperature below 800℃, and no peeling of oxide film was observed even holding for 6 hours.However, when atmosphere temperature exceeded 800℃ the oxidation tends to be aggressive, oxide film was found breaking off after oxidation for 30 minutes.SEM observation indicated that oxide layer composed of an oxide film and an oxide-rich layer.The oxide film is a mixture structure by several types of titanium oxides which are porous, brittle and readily break off, while the oxide-rich layer is a solid solution where oxygen atoms dissolved into titanium matrix.This oxide-rich layer is brittle but closely adhered to matrix and creates challenges for breaking down.XRD analysis pointed out that phase structure of oxide layer mainly contains TiO₂, TiO_0.325 and TiO_0.48.