Oxidation behavior of a burn resistant highly stabilized β titanium alloy

Ti40 alloy (Ti-25V-15Cr-0.2Si) is a highly stabilized β type burn resistant titanium alloy. Its oxidation behavior was studied. The weight gain increases greatly with the oxidation temperature, and then decreases when the oxidation temperature is over 1000°C. The oxidized products at 600°C are TiO₂ and V₂O₅. If the oxidation temperature is greater than 700°C, TiO₂ becomes the main product due to the vaporization of V₂O₅. The oxide scale cracks and peels off, if the temperature is over 900°C. SiO has been evidenced in the porous oxides if the temperature is over 800°C, and it vanishes as a result of scale spallation at 1050°C. A small amount of Cr₂O₃ has also been detected inside the scales and distributes non-continuously. Reasons of the fast oxidation are analyzed, and an oxidation model is suggested.