文献类型：期刊文献

英文题名：Gradient nanostructure induces exceptional cryogenic mechanical properties in an additively manufactured medium entropy alloy

作者：Yao, Ning[1];Lu, Tiwen[1];Sun, Binhan[1];Chen, Xiyu[1];Cheng, Weihong[1];Yang, Chao[1];Xie, Yu[1];Zhang, Xian-Cheng[1];Tu, Shan-Tung[1]

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

年份：2024

卷号：241

外文期刊名：SCRIPTA MATERIALIA

收录：;EI(收录号：20234715077765);WOS:【SCI-EXPANDED(收录号:WOS:001165305000001)】；

基金：This work was financially supported by the National key research and development program (2022YFB4602100) , National Natural Sci- ence Foundation of China (No. 52205152, No. 52275147) , and the Science Center for Gas Turbine Project from China (Project No. P2022 -C-III -002-001) .

语种：英文

外文关键词：Additive manufacturing; Medium entropy alloys; Heterostructures; Cryogenic mechanical properties

摘要：Developing additively manufactured alloys with high cryogenic performance can facilitate the development of geometrically complex components for cryogenic applications. In this study, we have implemented ultrasonic surface rolling process (USRP) on an additively manufactured CoCrNi-based medium entropy alloy to introduce a gradient nanostructure therein. The resulting alloy exhibits a substantial strength-ductility balance at 88 K, a relatively high ductility (24.6 %), 2.07 times higher than that at 293 K, as well as a yield strength as high as 1274 MPa. The exceptional yield strength is attributed to the high-density dislocations induced by additive manufacturing and ultrasonic surface rolling process, while the origin of impressive ductility promotion lies in two aspects, i.e., enhanced hetero -deformation induced hardening effect and activated twinning/microband behaviors at matrix region at 88 K. The former mainly comes from suppressed dynamic recovery in gradient layer. The latter is resulted from the lowered stacking faulting energy and high flow stress.