Effects of Cu additions on microstructure and mechanical properties of as-cast CrFeCoNiCux high-entropy alloy

作者：Hu, Qiang; Wang, Hai-ling^*; Qian, Li-hua; Zeng, Liang-cai; Wang, Qiang^*; Liu, Xin-wang

来源：TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA, 2023, 33(6): 1803-1813.

DOI：10.1016/S1003-6326(23)66223-5

• high-entropy alloy
• Cu-rich phase
• microstructure
• tensile strength
• fracture strain

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.

• 单位
  华中科技大学