Mechanically derived short-range order and its impact on the multi-principal-element alloys

Jae Bok Seol; Won-Seok Ko; Seok Su Sohn; Min Young Na; Hye Jung Chang; Yoon-Uk Heo; Jung Gi Kim; Hyokyung Sung; Zhiming Li; Elena Pereloma; Hyoung Seop Kim

doi:10.1038/s41467-022-34470-8

Mechanically derived short-range order and its impact on the multi-principal-element alloys

Nat Commun. 2022 Nov 9;13(1):6766. doi: 10.1038/s41467-022-34470-8.

Authors

Jae Bok Seol^#¹, Won-Seok Ko^#², Seok Su Sohn³, Min Young Na⁴, Hye Jung Chang⁴, Yoon-Uk Heo⁵, Jung Gi Kim⁶, Hyokyung Sung⁷, Zhiming Li⁸, Elena Pereloma⁹, Hyoung Seop Kim¹⁰

Affiliations

¹ Department of Materials Engineering and Convergence Technology, Center for K-metal & Microscopy, Gyeongsang National University, Jinju, 52828, South Korea. jb.seol@gnu.ac.kr.
² Department of Materials Science and Engineering, Inha University, Incheon, 22212, South Korea.
³ Department of Material Science and Engineering, Korea University, Seoul, 02841, South Korea.
⁴ Advanced Analysis and Data Center, Korea Institute of Science and Technology, Seoul, 25451, South Korea.
⁵ Graduate Institute of Ferrous and Energy Materials Technology, Pohang University of Science and Technology, Pohang, 37673, South Korea.
⁶ Department of Materials Engineering and Convergence Technology, Center for K-metal & Microscopy, Gyeongsang National University, Jinju, 52828, South Korea.
⁷ School of Materials Science and Engineering, Kookmin University, Seoul, 02707, South Korea.
⁸ Department of Materials Science, Central South University, Changsha, 410083, China.
⁹ School of Mechanical, Materials, Mechatronic and Biomedical Engineering & UOW Electron Microscopy Centre, University of Wollongong, Wollongong, NSW, 2522, Australia.
¹⁰ Graduate Institute of Ferrous and Energy Materials Technology, Pohang University of Science and Technology, Pohang, 37673, South Korea. hskim@postech.ac.kr.

^# Contributed equally.

Abstract

Chemical short-range order in disordered solid solutions often emerges with specific heat treatments. Unlike thermally activated ordering, mechanically derived short-range order (MSRO) in a multi-principal-element Fe₄₀Mn₄₀Cr₁₀Co₁₀ (at%) alloy originates from tensile deformation at 77 K, and its degree/extent can be tailored by adjusting the loading rates under quasistatic conditions. The mechanical response and multi-length-scale characterisation pointed to the minor contribution of MSRO formation to yield strength, mechanical twinning, and deformation-induced displacive transformation. Scanning and high-resolution transmission electron microscopy and the anlaysis of electron diffraction patterns revealed the microstructural features responsible for MSRO and the dependence of the ordering degree/extent on the applied strain rates. Here, we show that underpinned by molecular dynamics, MSRO in the alloys with low stacking-fault energies forms when loaded at 77 K, and these systems that offer different perspectives on the process of strain-induced ordering transition are driven by crystalline lattice defects (dislocations and stacking faults).

Abstract

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