| Unprecedented plastic flow channel in gamma-B-28 through ultrasoft bonds: A challenge to superhardness | |
| Zhang, S. H.1,2; Zheng, X.3; Jin, Q. Q.4; Zheng, S. J.4; Legut, D.5; Yu, X. H.3; Gou, H. Y.6; Fu, Z. H.1,2; Guo, Y. Q.1,2; Yan, B. M.6; Peng, C.6; Jin, C. Q.3; Germann, T. C.7; Zhang, R. F.1,2 | |
| Corresponding Author | Yu, X. H.(yuxh@iphy.ac.cn) ; Gou, H. Y.(huiyang.gou@hpstar.ac.cn) ; Zhang, R. F.(zrf@buaa.edu.cn) |
| 2018-12-13 | |
| Source Publication | PHYSICAL REVIEW MATERIALS
 |
| ISSN | 2475-9953 |
| Volume | 2Issue:12Pages:6 |
| Abstract | 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. |
| Funding Organization | 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 |
| DOI | 10.1103/PhysRevMaterials.2.123602 |
| Indexed By | SCI |
| Language | 英语 |
| Funding Project | 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 Research Area | Materials Science |
| WOS Subject | Materials Science, Multidisciplinary |
| WOS ID | WOS:000452971600001 |
| Publisher | AMER PHYSICAL SOC |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.imr.ac.cn/handle/321006/130803 |
| Collection | 中国科学院金属研究所 |
| Corresponding Author | Yu, X. H.; Gou, H. Y.; Zhang, R. F. |
| Affiliation | 1.Beihang Univ, Sch Mat Sci & Engn, Beijing 100191, Peoples R China 2.Beihang Univ, Int Res Inst Multidisciplinary Sci, Ctr Integrated Computat Mat Engn, Beijing 100191, Peoples R China 3.Chinese Acad Sci, Inst Phys, Beijing Natl Lab Condensed Matter, Beijing 100190, Peoples R China 4.Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Liaoning, Peoples R China 5.VSB Tech Univ Ostrava, TT4Innovat Ctr, CZ-70833 Ostrava, Czech Republic 6.Ctr High Pressure Sci & Technol Adv Res, Room C208,10 Dongbeiwang West Rd, Beijing 100094, Peoples R China 7.Los Alamos Natl Lab, Theoret Div, Los Alamos, NM 87545 USA |
| Recommended Citation 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. |
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