Breakdown of the Hall-Petch relationship in extremely fine nanograined body-centered cubic Mo alloys

doi:10.1016/j.actamat.2021.116950

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	Breakdown of the Hall-Petch relationship in extremely fine nanograined body-centered cubic Mo alloys
	Duan, F. H.1; Naunheim, Y.2; Schuh, C. A.2; Li, Y.1
刊名	ACTA MATERIALIA
	2021-07-01
卷号	213 页码:9
关键词	Nanocrystalline materials Hall-Petch breakdown Refractory bcc alloys Grain boundary Deformation behavior
ISSN号	1359-6454
DOI	10.1016/j.actamat.2021.116950
通讯作者	Schuh, C. A.(schuh@mit.edu) ; Li, Y.(liyi@imr.ac.cn)
英文摘要	Mechanical properties and deformation behavior have been studied in face-centered cubic (fcc) metals with extremely fine grain sizes, even below about 20 nm, but this range is rarely studied in the body centered cubic (bcc) metals. Here, we study the hardness and deformation behavior of bcc Mo(O) alloys with grain sizes from 120 to 4 nm, covering the range of classical Hall-Petch behavior as well as the regime where that scaling law breaks down, between about 11 and 4 nm. A hardness as high as 17.3 GPa was achieved at the strongest grain size of 11 nm, and the breakdown at smaller grain sizes is associated with a number of changes in behavior: an inflection in activation volume (associated with a change in rate dependence of deformation) and increasing shear localization. At coarser grain sizes this is associated with shear offsets at grain boundaries, pointing to an increasing prevalence of intergranular deformation (by sliding or grain rotation). At finer grain sizes localization is associated with the formation of large shear bands at scales far greater than the grain size. These behaviors are suggestive of a crossover from crystal-like to glass-like deformation behaviors at the finest grain sizes, consistent with the increasing fraction of disordered regions in the structure. (c) 2021 Published by Elsevier Ltd on behalf of Acta Materialia Inc.
资助项目	Shenyang National Laboratory for Materials Science[E01SL102] ; US National Science Foundation[DMR-2002860] ; NASA[80MSFC19C0050]
WOS研究方向	Materials Science ; Metallurgy & Metallurgical Engineering
语种	英语
出版者	PERGAMON-ELSEVIER SCIENCE LTD
WOS记录号	WOS:000670106400003
资助机构	Shenyang National Laboratory for Materials Science ; US National Science Foundation ; NASA
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/159922]
专题	金属研究所_中国科学院金属研究所
通讯作者	Schuh, C. A.; Li, Y.
作者单位	1.Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang, Peoples R China 2.MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA
推荐引用方式 GB/T 7714	Duan, F. H.,Naunheim, Y.,Schuh, C. A.,et al. Breakdown of the Hall-Petch relationship in extremely fine nanograined body-centered cubic Mo alloys[J]. ACTA MATERIALIA,2021,213:9.
APA	Duan, F. H.,Naunheim, Y.,Schuh, C. A.,&Li, Y..(2021).Breakdown of the Hall-Petch relationship in extremely fine nanograined body-centered cubic Mo alloys.ACTA MATERIALIA,213,9.
MLA	Duan, F. H.,et al."Breakdown of the Hall-Petch relationship in extremely fine nanograined body-centered cubic Mo alloys".ACTA MATERIALIA 213(2021):9.