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창의적인 신지식 창출과 산업계와의 협력적 네트워크 구축

금주의 우수논문

SCI-E Article
Temperature-dependent universal dislocation structures and transition of plasticity enhancing mechanisms of the Fe40Mn40Co10Cr10 high entropy alloy
김진경
  1. 성명
    김진경
  2. 소속
    공학대학 재료화학공학과
  3. 캠퍼스
  4. 우수선정주
    2022년 05월 2째주
Author
김진경 (Dept Mat Sci & Chem Engn) corresponding author; Park, Hyojin (Dept Mat Sci & Chem Engn); Kim, Jin-Seob (Dept Mat Sci & Chem Engn); Yang, Guanghui (Dept Mat Sci & Chem Engn); Kim, Rosa (Dept Mat Sci & Chem Engn); Kim, Jongryoul (Dept Mat Sci & Chem En
Corresponding Author Info
Kim, JK(해당 저자), Hanyang Univ, Dept Mat Sci & Chem Engn, Ansan 15588, South Korea.
E-mail
이메일jinkyungkim@hanyang.ac.kr
Document Type
Article
Source
INTERNATIONAL JOURNAL OF PLASTICITY Volume:148 Issue: Pages:- Published:2022
Times Cited
0
External Information
http://dx.doi.org/10.1016/j.ijplas.2021.103148
Abstract
The FCC Fe40Mn40Co10Cr10 (at.%) high entropy alloy exhibits deformation twinning for room temperature deformation and deformation-induced HCP transformation for subzero deformation. Since the systematic investigation of temperature-dependent dislocation structures is not available, we present an in-depth characterization of the defects involved in deformation at room temperature (298 K) and subzero temperature (223 K) of the cold-rolled and annealed Fe40Mn40Co10Cr10 alloy. The material deformed at 223 K shows a higher strain hardening rate than the material deformed at room temperature while both materials show large ductility, 48% for the 223 K deformation and 55% for the 298 K deformation. The main deformation mechanisms of the investigated HEA include the development of inhomogeneous dislocation structures and interaction between dislocations and deformation twin/mechanically induced HCP martensite. The stacking fault energy measured using TEM weak-beam dark-field imaging of dissociated dislocations is 20 +/- 9 mJ/m(2) at 298 K. The & nbsp;Fe40Mn40Co10Cr10 alloy exhibiting a positive temperature dependence of SFE leads to a decrease of SFE as deformation temperature decreases from 298 K to 223 K. The decrease of SFE results in the transition from deformation twinning to deformation-induced HCP transformation. Further, at higher strains at 223 K, kink banding of HCP and reverse transformation from HCP to FCC were observed, which could account for strain accommodation and stress relaxation, and the large ductility. The 298 K deformation leads to various types of dislocation structures: Extended dislocations, Taylor lattice of perfect dislocations, dislocation loops, highly dense dislocation walls, cell blocks, and cell structures. The observed dislocation structures at 298 K and 223 K are similar suggesting the minor effect of SFE on dislocation structures.
Web of Science Categories
Engineering, Mechanical; Materials Science, Multidisciplinary; Mechanics
Funding
Basic Science Research Program through the National Research Foundation of Korea - Ministry of Education [2018R1D1A1B07044731, NRF-2021R1F1A1046001]; Korea Institute for Advancement of Tech-nology (KIAT) - Korea Government (MOTIE) [P0002019]
Language
English
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