中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 30 No. 5 May 2020 |
（1. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;
2. Department of Materials Engineering, Baotou Vocational & Technical College, Baotou 014030, China;
3. The fifth Branch Company, Inner Mongolia First Machinery Group Corporation Limited, Baotou 014032, China）
Abstract:In order to improve mechanical properties and optimize composition of TiAl-Nb alloys, Ti46Al5Nb0.1B alloys with different contents of Fe (0, 0.3, 0.5, 0.7, 0.9, and 1.1 at.%) were prepared by melting. Macro/microstructure and compression properties of the alloys were systematically investigated. Results show that Fe element can decrease the grain size, aggravate the Al-segregation and also form the Fe-rich B2 phase in the interdendritic area. Compressive testing results indicate that the Ti46Al5Nb0.1B0.3Fe alloy shows the highest ultimate compressive strength and fracture strain, which are 1869.5 MPa and 33.53%, respectively. The improved ultimate compression strength is ascribed to the grain refinement and solid solution strengthening of Fe, and the improved fracture strain is due to the reduced lattice tetragonality of γ phase and grain refinement of the alloys. However, excessive Fe addition decreases compressive strength and fracture strain, which is caused by the severe Al-segregation.
Key words: TiAl alloy; Fe; B2 phase; microstructure; mechanical properties
