Disentangling diffusion heterogeneity in high-entropy alloys

doi:10.1016/j.actamat.2021.117527

IMECH-IR > 非线性力学国家重点实验室

	Disentangling diffusion heterogeneity in high-entropy alloys
	Wang YZ(王一舟)1,2; Wang YJ(王云江)1,2
通讯作者	Wang, Yun-Jiang(yjwang@imech.ac.cn)
发表期刊	ACTA MATERIALIA
	2022-02-01
卷号	224 页码:9
ISSN	1359-6454
摘要	Diffusion in the traditional single-crystalline solids is usually dynamically homogeneous characterized by a single-value or two characteristic activation energies. However, such a scenario breaks down at atomicscale in the recently advanced high-entropy alloys, which are of unique structural features with multiprincipal elements randomly occupying on lattice sites that induces strikingly local chemical heterogeneity. Here we uncover and decouple the possible dynamic heterogeneity accommodating the lattice diffusion in an archetypical high-entropy Cantor alloy CoCrFeMnNi via combined molecular statics, molecular dynamics, and a saddle-point sampling method. Wide distribution of vacancy formation energies and migration energies are revealed. We propose a single-vacancy and a vacancy-saturated model, respectively, to set up possible lower bound and upper bound of diffusivities. The models define a possible range of activation energies for the lattice diffusion in high-entropy alloys, which are comparable to experimental data. Finally, we argue that the conventional hypothesis of diffusion activation energy estimated from Arrhenius equation as the sum of the vacancy formation energy and migration energy becomes intractable in high-entropy alloys. These atomic-scale insights into diffusion heterogeneity, in contrast to the classical theory of homogeneous diffusion in conventional solid solutions, highlight the complexity of diffusion pathways and the intimate correlation between chemical, topological disorder and dynamic heterogeneity in the generic complex concentrated alloys.(c) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
关键词	Diffusion Dynamic heterogeneity High-entropy alloy Molecular dynamics
DOI	10.1016/j.actamat.2021.117527
收录类别	SCI ; EI
语种	英语
WOS记录号	WOS:000789151600007
关键词[WOS]	SHORT-RANGE ORDER ; TRACER DIFFUSION ; SLUGGISH DIFFUSION ; MOLECULAR-DYNAMICS ; SELF-DIFFUSION ; MECHANISM ; COMPLEX ; CO ; RELAXATION ; COCRFENI
WOS研究方向	Materials Science ; Metallurgy & Metallurgical Engineering
WOS类目	Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering
资助项目	National Natural Sci-ence Foundation of China[12072344] ; Youth Innovation Promotion Association of the Chinese Academy of Sciences[2017025]
项目资助者	National Natural Sci-ence Foundation of China ; Youth Innovation Promotion Association of the Chinese Academy of Sciences
论文分区	一类
力学所作者排名	1
RpAuthor	Wang, Yun-Jiang
引用统计	被引频次：27[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://dspace.imech.ac.cn/handle/311007/89103
专题	非线性力学国家重点实验室
作者单位	1.Chinese Acad Sci, Inst Mech, State Key Lab Nonlinear Mech, Beijing 100190, Peoples R China; 2.Univ Chinese Acad Sci, Sch Engn Sci, Beijing 101408, Peoples R China
推荐引用方式 GB/T 7714	Wang YZ,Wang YJ. Disentangling diffusion heterogeneity in high-entropy alloys[J]. ACTA MATERIALIA,2022,224:9.
APA	王一舟,&王云江.(2022).Disentangling diffusion heterogeneity in high-entropy alloys.ACTA MATERIALIA,224,9.
MLA	王一舟,et al."Disentangling diffusion heterogeneity in high-entropy alloys".ACTA MATERIALIA 224(2022):9.

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