Abstract:The non-isothermal oxidation tests ofthe near-α high-temperature titanium alloys (Ti150) without graphene oxide (GO) and with 0.5 wt.% GO were carried out at room temperature ~1500 ℃ by thermogravimetry-differential scanning calorimetry method. The influence mechanism of GO on non-isothermal oxidation behavior was revealed by analyzing the oxidation mass gain laws and the microstructure characteristics of oxidation products. The results showed that the non-isothermal oxidation process of Ti150 alloy with GO included almost no oxidation (≤800 ℃), slow dissolution of oxygen in α phase (800~1160 ℃), accelerated dissolution of oxygen in two-phase region (1160~1300 ℃), rapid dissolution of oxygen in β phase (1300~1330 ℃), and violent growth of oxide scale (1330~1500 ℃) five stages. The dissolution of oxygen in β phase and growth of oxide scale were the main reasons for the non-isothermal oxidation mass gain. After non-isothermal oxidation to 1500 ℃, the non-isothermal oxidation mass gain and oxide scale thickness of Ti150 alloy with GO were 10.8% and 17.9% lower than those without GO, respectively. The main mechanism of GO improving the non-isothermal oxidation resistance was that the beginning temperature of rapid dissolution of oxygen in β-Ti was delayed due to the higher β-transus temperature of Ti150 alloy with GO, which resulted in the decrease of oxygen solution, and the finer grain made the Al2O3-rich oxide layer and the Sn-rich layer more continuous and dense, which were more effective barriers to ion diffusion.