文章基本信息

标题：Unusual activated processes controlling dislocation motion in body-centered-cubic high-entropy alloys
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作者：Bing Chen ; Suzhi Li ; Hongxiang Zong 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2020
卷号：117
期号：28
页码：16199-16206
DOI：10.1073/pnas.1919136117
出版社：The National Academy of Sciences of the United States of America
摘要：Atomistic simulations of dislocation mobility reveal that body-centered cubic (BCC) high-entropy alloys (HEAs) are distinctly different from traditional BCC metals. HEAs are concentrated solutions in which composition fluctuation is almost inevitable. The resultant inhomogeneities, while locally promoting kink nucleation on screw dislocations, trap them against propagation with an appreciable energy barrier, replacing kink nucleation as the rate-limiting mechanism. Edge dislocations encounter a similar activated process of nanoscale segment detrapping, with comparable activation barrier. As a result, the mobility of edge dislocations, and hence their contribution to strength, becomes comparable to screw dislocations.
关键词：BCC high-entropy alloys ; dislocation mobility ; local composition ; solid-solution trapping