연구진흥

창의적인 신지식 창출과 산업계와의 협력적 네트워크 구축

금주의 우수논문

SCI-E Article
Hierarchical precipitates, sequential deformation-induced phase transformation, and enhanced back stress strengthening of the micro-alloyed high entropy alloy
김진경
  1. 성명
    김진경
  2. 소속
    공학대학 재료화학공학과
  3. 캠퍼스
  4. 우수선정주
    2022년 08월 2째주
Author
Yang, Guanghui (Dept Mat Sci & Chem Engn); 김진경 (Dept Mat Sci & Chem Engn) corresponding author;
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
ACTA MATERIALIA Volume:233 Issue: Pages:- Published:2022
Times Cited
0
External Information
http://dx.doi.org/10.1016/j.actamat.2022.117974
Abstract
We report the annealing time-dependent microstructures and deformation mechanisms of the novel face-centered cubic Fe49.5Mn30Co10Cr10C0.2Ti0.1V0.1 Mou HEA. Three types of precipitates, sigma-phase, Cr-rich MC-type carbides, and nano-scale (Ti, V, Mo)C, are present after cold-rolling and annealing at 600 degrees C. Such hierarchical precipitates could lead to sluggish recrystallization and grain growth upon annealing. The partially recrystallized microstructures and hierarchical precipitates could lead to a high yield strength even for prolonged annealing conditions. Deformation mechanisms change with annealing time. The materials annealed for short times (˂ 2 h) are deformed by dislocation glide, deformation twinning, and deformation-induced epsilon phase. A longer annealing time (˃ 10 h) triggers a multi-variant epsilon phase, reverse transformation from epsilon to gamma, and the multi-step sequential transformation, gamma -˃ epsilon -˃ reverse transformed gamma from epsilon -˃ epsilon transformed from the reverse transformed gamma. Further, materials annealed for longer times shows a higher contribution of back stress strengthening, which could be attributed to the increase in gamma/epsilon and gamma/sigma interfaces. The activation of various deformation mechanisms and high back stress strengthening could lead to a superior strain hardening capacity and strength-ductility combination (YS: 699 MPa, UTS: 1041 MPa, TE: 45%) of the material annealed for 10 h. The present work provides the novel microstructure design solution of the metastable high entropy alloys with exceptional mechanical properties, utilizing hierarchical precipitates, sequential deformation-induced phase transformation, and enhanced back stress strengthening. (C) 2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Web of Science Categories
Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering
Funding
Basic Science Research Program through the National Research Foundation of Korea - Ministry of Education [2018R1D1A1B07044731, NRF-2021R1F1A1046001]
Language
English
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