期刊
MATERIALS & DESIGN
卷 233, 期 -, 页码 -出版社
ELSEVIER SCI LTD
DOI: 10.1016/j.matdes.2023.112250
关键词
High entropy alloy; Microfiber; Mechanical properties; Cryogenic temperature; Microstructure
This study introduces a heterogeneous gradient structure into CoCrFeNi high-entropy alloy microfibers through thermomechanical processing, achieving an excellent combination of high strength and ductility. The microfibers show ultrahigh yield strength and outstanding uniform elongation at low temperatures, thanks to the ultrafine grains, heterogeneous gradient structure, and activation of multiple deformation mechanisms.
Exploring metallic microfibers with an excellent combination of high strength and ductility is a challenge for structural applications under extreme conditions. In this work, a heterogeneous gradient structure was introduced into CoCrFeNi high-entropy alloy (HEA) microfibers via thermomechanical processing. The annealed CoCrFeNi microfiber displays an ultrahigh yield strength of similar to 1 GPa, an ultimate tensile strength of 1.45 GPa, and an outstanding uniform elongation of 75% at 150 K. These excellent properties originate from the ultrafine grains and heterogeneous gradient structure, as well as the activation of multiple deformation mechanisms including deformation twins, dense dislocations, stacking faults, Lomer-Cottrell locks, phase transformation and 9R phase. Our work not only suggests that HEA microfibers have great potential for structural applications in cryogenic environments, but also sheds light on the design of advanced multi-component metallic microfibers with superior mechanical properties.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据