中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 35 No. 6 June 2025 |
（1. College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China;
2. National Center for Materials Service Safety, University of Science and Technology Beijing, Beijing 100083, China;
3. State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:A Cr/CoNiCrAlTaY bilayer coating was prepared on the Ti-45Al-8.5Nb alloy by plasma surface metallurgy technique. The as-prepared coating with a grain size of ~2 μm exhibited a dense microstructure and strong adhesion due to metallurgical bonding, consisting of outermost Cr layer and CoNiCrAlTaY transition layer. The typical power-law relationship between mass gain and time was obtained for the coated specimens with a rate exponent of 3.18 following oxidation at 1173 K. The top Cr2O3 film and spinel oxides (i.e., NiCr2O4 and CoCr2O4) exhibited a protective effect with a low oxidation reaction rate. Interfacial analysis identified Ta precipitates (Cr2Ta and TaAl3) and Ta oxides (Ta2O5 and Ta2O3), which played an essential role in retarding rapid diffusion and enhancing adhesion and oxidation resistance.
Key words: TiAl alloy; Cr/CoNiCrAlTaY coating; oxidation resistance; interface; adhesion
