文献类型：期刊文献

英文题名：Cryoforged nanotwinned CoCrNi medium-entropy alloy with exceptional fatigue property at cryogenic temperature

作者：Xie, Yu[1];Lu, Tiwen[1];Zhao, Pengcheng[1];Sun, Binhan[1];Yao, Ning[1];Chen, Xiyu[1];Tan, Jianping[1];Zhang, Xian-Cheng[1];Tu, Shan-Tung[1]

机构：[1]East China Univ Sci & Technol, Key Lab Pressure Syst & Safety, Minist Educ, Shanghai 200237, Peoples R China

年份：2023

卷号：237

外文期刊名：SCRIPTA MATERIALIA

收录：;EI(收录号：20233414613587);WOS:【SCI-EXPANDED(收录号:WOS:001067585300001)】；

基金：This work was financially supported by the National key research and development program (2022YFB4602100), National Natural Science Foundation of China (Nos. 52205152, 52275147, 52105144, 52075174), Science Center for gas turbine project from China (Project No. P2022-C-III- 002-001).

语种：英文

外文关键词：CoCrNi medium-entropy alloys; Multidirectional cryoforging; Hierarchical nanotwins; Cryogenic fatigue property

摘要：The extraordinary work hardening ability and fracture toughness of the face-centered cubic medium-entropy alloy (MEA) at cryogenic temperature make them good candidates for harsh applications. In this work, we developed a hierarchical twin architecture in coarse grained CoCrNi MEA using multidirectional cryoforging (MDCF) technique and low-temperature annealing. The unique substructure brought a notable enhancement in the cryogenic tensile strength-ductility balance, as well as an impressive 106-cycle fatigue strength of up to 1100 MPa at cryogenic temperature, which is superior to other cryogenic alloys. The exceptional fatigue property of MDCF-MEA is ascribed to the synergistic effect of high-density dislocations and a dense nanotwin/microband network, providing high strength and the ability to suppress local surface roughening and crack initiation. Our work demonstrates a practical route to further extend CoCrNi MEA for the cryogenic application.