TY - JOUR
T1 - Deformation behavior of a Co-Cr-Fe-Ni-Mo medium-entropy alloy at extremely low temperatures
AU - Moon, Jongun
AU - Tabachnikova, Elena
AU - Shumilin, Sergii
AU - Hryhorova, Tetiana
AU - Estrin, Yuri
AU - Brechtl, Jamieson
AU - Liaw, Peter K.
AU - Wang, Wenqing
AU - Dahmen, Karin A.
AU - Zargaran, Alireza
AU - Bae, Jae Wung
AU - Do, Hyeon Seok
AU - Lee, Byeong Joo
AU - Kim, Hyoung Seop
N1 - Funding Information:
We are most grateful to the Editor and Reviewers for their excellent comments. The present work was supported by the Korea-Ukraine Bilateral Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and Information and Communication Technology (ICT) [NRF- 2018K1A3A1A13087775 ]. The research was also supported by (1) the Future Materials Discovery Program through the NRF funded by the Ministry of Science and ICT [ NRF-2016M3D1A1023384 ], and (2) the NRF grant funded by the Korea government (MSIP) [ NRF-2021R1A2C3006662 ]. P. K. L. acknowledges the support from (1) the U.S. Army Office Project [W911NF-13-1-0438 and W911NF-19-2-0049] with the program managers, Drs. Michael P. Bakas, David M. Stepp, and S. Mathaudhu, and (2) the National Science Foundation [DMR-1611180 and 1809640] with the program directors, Drs. Judith Yang, Gary Shiflet, and Diana Farkas.
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2021/11
Y1 - 2021/11
N2 - We report the mechanical and microstructural characteristics of a medium-entropy alloy, Co17.5Cr12.5Fe55Ni10Mo5 (atomic percent, at%) at cryogenic temperatures, down to a record low temperature of 0.5 K. The alloy exhibits excellent strength and ductility combined with a high strain-hardening rate in the entire temperature range investigated. Its property profile, including the yield strength, ultimate tensile strength, strain hardening capability, and absorbed mechanical energy, is better than those of most alloys and HEAs used in cryogenics. Within the interval of extremely low temperatures considered (0.5–4.2 K), the alloy exhibits several unusual features, including anomalies of the temperature dependence of the yield strength and tensile ductility, discontinuous plastic deformation (DPF), and a change in the propensity for the deformation-induced martensitic transformation. While the occurrence of these effects in the same temperature interval may be fortuitous, we hypothesize that they are interrelated and provide a tentative explanation of the observed phenomena on this basis.
AB - We report the mechanical and microstructural characteristics of a medium-entropy alloy, Co17.5Cr12.5Fe55Ni10Mo5 (atomic percent, at%) at cryogenic temperatures, down to a record low temperature of 0.5 K. The alloy exhibits excellent strength and ductility combined with a high strain-hardening rate in the entire temperature range investigated. Its property profile, including the yield strength, ultimate tensile strength, strain hardening capability, and absorbed mechanical energy, is better than those of most alloys and HEAs used in cryogenics. Within the interval of extremely low temperatures considered (0.5–4.2 K), the alloy exhibits several unusual features, including anomalies of the temperature dependence of the yield strength and tensile ductility, discontinuous plastic deformation (DPF), and a change in the propensity for the deformation-induced martensitic transformation. While the occurrence of these effects in the same temperature interval may be fortuitous, we hypothesize that they are interrelated and provide a tentative explanation of the observed phenomena on this basis.
KW - Cryogenic temperatures
KW - Discontinuous plastic deformation
KW - Dislocation
KW - Martensitic phase transformation
KW - Medium-entropy alloy
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U2 - 10.1016/j.mattod.2021.08.001
DO - 10.1016/j.mattod.2021.08.001
M3 - Article
AN - SCOPUS:85116309579
SN - 1369-7021
VL - 50
SP - 55
EP - 68
JO - Materials Today
JF - Materials Today
ER -