Unprecedented plastic flow channel in gamma-B-28 through ultrasoft bonds: A challenge to superhardness

doi:10.1103/PhysRevMaterials.2.123602

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	Unprecedented plastic flow channel in gamma-B-28 through ultrasoft bonds: A challenge to superhardness
	Zhang, S. H.2,3; Zheng, X.4; Jin, Q. Q.5; Zheng, S. J.5; Legut, D.6; Yu, X. H.4; Gou, H. Y.7; Fu, Z. H.2,3; Guo, Y. Q.2,3; Yan, B. M.7
刊名	PHYSICAL REVIEW MATERIALS
	2018-12-13
卷号	2 期号:12 页码:6
ISSN号	2475-9953
DOI	10.1103/PhysRevMaterials.2.123602
通讯作者	Yu, X. H.(yuxh@iphy.ac.cn) ; Gou, H. Y.(huiyang.gou@hpstar.ac.cn) ; Zhang, R. F.(zrf@buaa.edu.cn)
英文摘要	A longstanding controversy remains whether gamma-B-28 is intrinsically superhard or not, i.e., H-upsilon >= 40 GPa. Here we perform comprehensive investigations on the mechanical properties of gamma-B-28 to reveal the plasticity and failure mode of gamma-B-28 through the unique combination of microindentation experiment, the ideal strength approach, and the ab initio informed Peierls-Nabarro model. A low load-invariant hardness of similar to 30 GPa is found for both polycrystalline and monocrystalline gamma-B-28. By carefully checking the strength anisotropy and strain facilitated phonon instability, a surprising ideal strength of 23.1 GPa is revealed along the (001)[010] slip system for gamma-B-28, together with an inferior Peierls stress of 3.2 GPa, both of which are close to those of B6O and ZrB12 yet much lower than those of diamond and c-BN. These results suggest that gamma-B-28 could not be intrinsically superhard. Atomistic simulation and electronic structure analysis uncover an unprecedented plastic flow channel through the specific ultrasoft bonding, which causes a dramatic softening of gamma-B-28. These findings highlight an approach to quantifying the realistic hardness by means of two plasticity descriptors beyond the elastic limit, i.e., the ideal strength approach and the Peierls-Nabarro model.
资助项目	National Natural Science Foundation of China[51672015] ; National Natural Science Foundation of China[51201148] ; National Natural Science Foundation of China[U1530402] ; National Natural Science Foundation of China[11575288] ; National Natural Science Foundation of China[51402350] ; National Key Research and Development Program of China[2016YFC1102500] ; National Thousand Young Talents Program of China ; Fundamental Research Funds for the Central Universities ; project IT4Innovations: Path to Exascale[CZ.02.1.01/0.0/0.0/16_013/0001791] ; Czech Science Foundation[17-27790S] ; National Programme of Sustainability[LQ1602] ; National Key R&D Program of China[2016YFA0401503]
WOS研究方向	Materials Science
语种	英语
出版者	AMER PHYSICAL SOC
WOS记录号	WOS:000452971600001
资助机构	National Natural Science Foundation of China ; National Key Research and Development Program of China ; National Thousand Young Talents Program of China ; Fundamental Research Funds for the Central Universities ; project IT4Innovations: Path to Exascale ; Czech Science Foundation ; National Programme of Sustainability ; National Key R&D Program of China
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/130802]
专题	金属研究所_中国科学院金属研究所
通讯作者	Yu, X. H.; Gou, H. Y.; Zhang, R. F.
作者单位	1.Los Alamos Natl Lab, Theoret Div, Los Alamos, NM 87545 USA 2.Beihang Univ, Sch Mat Sci & Engn, Beijing 100191, Peoples R China 3.Beihang Univ, Int Res Inst Multidisciplinary Sci, Ctr Integrated Computat Mat Engn, Beijing 100191, Peoples R China 4.Chinese Acad Sci, Inst Phys, Beijing Natl Lab Condensed Matter, Beijing 100190, Peoples R China 5.Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Liaoning, Peoples R China 6.VSB Tech Univ Ostrava, TT4Innovat Ctr, CZ-70833 Ostrava, Czech Republic 7.Ctr High Pressure Sci & Technol Adv Res, Room C208,10 Dongbeiwang West Rd, Beijing 100094, Peoples R China
推荐引用方式 GB/T 7714	Zhang, S. H.,Zheng, X.,Jin, Q. Q.,et al. Unprecedented plastic flow channel in gamma-B-28 through ultrasoft bonds: A challenge to superhardness[J]. PHYSICAL REVIEW MATERIALS,2018,2(12):6.
APA	Zhang, S. H..,Zheng, X..,Jin, Q. Q..,Zheng, S. J..,Legut, D..,...&Zhang, R. F..(2018).Unprecedented plastic flow channel in gamma-B-28 through ultrasoft bonds: A challenge to superhardness.PHYSICAL REVIEW MATERIALS,2(12),6.
MLA	Zhang, S. H.,et al."Unprecedented plastic flow channel in gamma-B-28 through ultrasoft bonds: A challenge to superhardness".PHYSICAL REVIEW MATERIALS 2.12(2018):6.