Abstract:TiAl alloy is a lightweight superalloy with broad application prospects in aerospace field. Electron beam selective melting(EBM) additive manufacturing technology is an effective way to prepare TiAl alloy with complex structure. However, there are few studies on high temperature properties of TiAl alloy. In this paper, the microstructure, high-temperature hardness and high-temperature oxidation behavior of Ti-48Al-2Cr-2Nb alloy fabricated by electron beam selective melting additive are mainly studied. The results show that the Ti-48Al-2Cr-2Nb alloy formed by EBM exhibits a unique layered structure composed of equiaxed γ grains and double phase regions. After isothermal oxidation at 800 °C for 100 h, this alloy shows a low oxidation rate constant, and the formed oxide film is mainly composed of TiO2, Al2O3 and TiO2 / Al2O3 mixed alternating layers. The oxidation resistance is better than that of Ti-48Al-2Cr-2Nb alloy and other TiAl alloy prepared by traditional methods. In addition, this alloy has good high temperature hardness at below 900 ℃, and the microhardness does not decrease significantly with the increase of temperature.