中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 33 No. 6 June 2023 |
（1. Institute of Applied Physics, Jiangxi Academy of Sciences, Nanchang 330029, China;
2. School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China;
3. Key Laboratory of Metallurgical Equipment and Control Technology, Ministry of Education, School of Machinery and Automation, Wuhan University of Science and Technology, Wuhan 430081, China;
4. Hubei Key Laboratory of Mechanical Transmission and Manufacturing Engineering, School of Machinery and Automation, Wuhan University of Science and Technology, Wuhan 430081, China;
5. State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China）
Abstract:The influences of Cu additions on the microstructural evolution and room-temperature tensile properties of the as-cast CrFeCoNi were investigated in detail. The results revealed that the structure of the alloy changed from a FCC single-phase to FCC1 plus FCC2 dual-phase by adding Cu element. The FCC2 phase was determined to be Cu-rich phase existing in the inter-dendrite region, and its volume fraction increased with the increase of Cu additions. The formation of Cu-rich inter-dendrite was mainly ascribed to the liquid-phase separation induced by the large positive mixing enthalpy between Cu and other metallic elements. The yield and ultimate tensile strengths against the Cu content displayed a positive correlation due to the enhancement of short-range obstacles to dislocations slip, while the more significant superposition of stress field produced by the dislocation piling-ups at grain boundaries of Cu-containing high-entropy alloys led to a small fracture strain.
Key words: high-entropy alloy; Cu-rich phase; microstructure; tensile strength; fracture strain
