Laser Alloying for Improvement of Oxidation Resistance at 1000℃ of Ti5Si3/Ti3Al Composite Coating on TA2 Titanium Alloy
HUANG Kaijin1,2, HUANG Wanxia1, LIN Xin2, WANG Aihua1
1. State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430074, China;
2. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China
To improve the high temperature oxidation resistance of titanium and titanium alloys, a Ti5Si3/Ti3Al composite coating with oxidation resistance at 1000℃ was prepared by laser alloying on TA2 titanium alloy with inner layer of silicon powder and outer layer of aluminum powder. XRD, SEM and isothermal oxidation technology were used to study the microstructure and the air isothermal oxidation performance of the coating at 1000℃ for 50h. The results show that the composite coating is mainly composed of primary Ti5Si3 phase and Ti5Si3/Ti3Al eutectic structure; the oxidative weight gain rate of the composite coating is about one twelfth of that of the substrate; the oxidation products of the composite coating are mainly TiO2, Al2O3 and SiO2; the existence of two phases Ti5Si3 and Ti3Al in the composite coating is the main reason for the improvement of its oxidation resistance at 1000℃ .
2018, 
