Disentangling diffusion heterogeneity in high-entropy alloys

doi:10.1016/j.actamat.2021.117527

CORC > 力学研究所 > 中国科学院力学研究所 > 非线性力学国家重点实验室

	Disentangling diffusion heterogeneity in high-entropy alloys
	Wang, Yi-Zhou 1,2; Wang, Yun-Jiang 1,2
刊名	ACTA MATERIALIA
	2022-02-01
卷号	224 页码:9
关键词	Diffusion Dynamic heterogeneity High-entropy alloy Molecular dynamics
ISSN号	1359-6454
DOI	10.1016/j.actamat.2021.117527
通讯作者	Wang, Yun-Jiang(yjwang@imech.ac.cn)
英文摘要	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.
资助项目	National Natural Sci-ence Foundation of China[12072344] ; Youth Innovation Promotion Association of the Chinese Academy of Sciences[2017025]
WOS关键词	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
语种	英语
WOS记录号	WOS:000789151600007
资助机构	National Natural Sci-ence Foundation of China ; Youth Innovation Promotion Association of the Chinese Academy of Sciences
内容类型	期刊论文
源URL	[http://dspace.imech.ac.cn/handle/311007/89102]
专题	力学研究所_非线性力学国家重点实验室
通讯作者	Wang, Yun-Jiang
作者单位	1.Univ Chinese Acad Sci, Sch Engn Sci, Beijing 101408, Peoples R China 2.Chinese Acad Sci, Inst Mech, State Key Lab Nonlinear Mech, Beijing 100190, Peoples R China
推荐引用方式 GB/T 7714	Wang, Yi-Zhou,Wang, Yun-Jiang. Disentangling diffusion heterogeneity in high-entropy alloys[J]. ACTA MATERIALIA,2022,224:9.
APA	Wang, Yi-Zhou,&Wang, Yun-Jiang.(2022).Disentangling diffusion heterogeneity in high-entropy alloys.ACTA MATERIALIA,224,9.
MLA	Wang, Yi-Zhou,et al."Disentangling diffusion heterogeneity in high-entropy alloys".ACTA MATERIALIA 224(2022):9.