Hierarchically structured diamond composite with exceptional toughness
Hierarchically structured diamond composite with exceptional toughness
复制标题
具有卓越韧性的分级结构金刚石复合材料
DOI：
10.1038/s41586-020-2361-2
复制
发表时间：
2020-06
期刊：
影响因子：
64.8
通讯作者：
Yongjun Tian
中科院分区：
文献类型：
--
作者：
Bo Xu;Wentao Hu;Yufei Gao;Yonghai Yue;Jing Wang;Xuejiao Zhang;Qi Zhang;Yanbin Wang;Binghui Ge;Zhenyu Yang;Zihe Li;Pan Ying;Xiaoxiao Liu;Dongli Yu;Bin Wei;Zhongchang Wang;Xiang-Feng Zhou;Lin Guo;Yongjun Tian
众所周知，硬度和韧性（抗断裂性）之间的权衡使得同时提高这两种性能具有挑战性，特别是在金刚石中。金刚石的硬度可以通过纳米结构策略来提高，其中高密度纳米孪晶的形成——由对称相关的晶体区域——也可以使金刚石增韧。在金刚石以外的材料中，除了纳米孪晶之外，还有其他几种有前途的增强韧性的方法，如仿生层合复合增韧、相变增韧和双相增韧，但在金刚石中对这些方法的研究很少。在这里，我们报告了一种金刚石复合材料的结构特征，该复合材料由连贯界面的金刚石多型（不同的堆叠顺序）、交织的纳米孪晶和互锁的纳米颗粒分层组装而成。复合材料的结构比单独的纳米孪晶更能提高韧性，而不会牺牲硬度。单刃缺口光束测试的韧性是人造金刚石的5倍，甚至超过镁合金。当断裂发生时，裂纹沿{111}面沿之字形路径在3C（立方）多型金刚石纳米孪晶中扩展。当裂纹遇到非3C多型区域时，其扩展扩展为弯曲断裂，并在断口附近局部转化为3C金刚石。这两种过程都能消散应变能，从而提高韧性。这项工作在制造超硬材料和工程陶瓷方面可能是有用的。通过采用具有硬化和增韧协同作用的结构结构，最终可以克服硬度和韧性之间的权衡。
The well known trade-off between hardness and toughness (resistance to fracture) makes simultaneous improvement of both properties challenging, especially in diamond. The hardness of diamond can be increased through nanostructuring strategies,, among which the formation of high-density nanoscale twins — crystalline regions related by symmetry — also toughens diamond. In materials other than diamond, there are several other promising approaches to enhancing toughness in addition to nanotwinning, such as bio-inspired laminated composite toughening, , –, transformation toughening and dual-phase toughening, but there has been little research into such approaches in diamond. Here we report the structural characterization of a diamond composite hierarchically assembled with coherently interfaced diamond polytypes (different stacking sequences), interwoven nanotwins and interlocked nanograins. The architecture of the composite enhances toughness more than nanotwinning alone, without sacrificing hardness. Single-edge notched beam tests yield a toughness up to five times that of synthetic diamond, even greater than that of magnesium alloys. When fracture occurs, a crack propagates through diamond nanotwins of the 3C (cubic) polytype along {111} planes, via a zigzag path. As the crack encounters regions of non-3C polytypes, its propagation is diffused into sinuous fractures, with local transformation into 3C diamond near the fracture surfaces. Both processes dissipate strain energy, thereby enhancing toughness. This work could prove useful in making superhard materials and engineering ceramics. By using structural architecture with synergetic effects of hardening and toughening, the trade-off between hardness and toughness may eventually be surmounted.
登录
查看更多内容
分级结构生物材料中纳米孪晶控制的增韧机制
影响因子：
16.6
作者：
Shin YA;Yin S;Li X;Lee S;Moon S;Jeong J;Kwon M;Yoo SJ;Kim YM;Zhang T;Gao H;Oh SH
通讯作者：
Oh SH
影响因子：
19
作者：
Y. Zhang;X. Han;K. Zheng;Z. Zhang;X. Zhang;J. Fu;Y. Ji;Y. Hao;X. Guo;Z. Wang
通讯作者：
Y. Zhang;X. Han;K. Zheng;Z. Zhang;X. Zhang;J. Fu;Y. Ji;Y. Hao;X. Guo;Z. Wang
影响因子：
3.7
作者：
Kresse, G;Furthmuller, J
通讯作者：
Furthmuller, J
DOI：
10.1073/pnas.1214976109
发表时间：
2012-11-20
影响因子：
11.1
作者：
Ji, Cheng;Levitas, Valery I.;Ma, Yanzhang
通讯作者：
Ma, Yanzhang
影响因子：
41.2
作者：
Koester, K. J.;Ager, J. W., III;Ritchie, R. O.
通讯作者：
Ritchie, R. O.