Bu Yeqiang, Su Zhengping, Huang Junquan, Tong Ke, Li Penghui, Wang Chong, Jin Tianye, Zhao Song, Zhao Zhisheng, Soldatov Alexander, Wang Yanbin, Xu Bo, Liu Zhongyuan, Nie Anmin, Wang Hongtao, Yang Wei, Tian Yongjun
Center for High Pressure Science, State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, China.
Center for X-mechanics, School of Aeronautics and Astronautics, Zhejiang University, Hangzhou, China.
Nat Mater. 2025 Mar;24(3):361-368. doi: 10.1038/s41563-024-02111-8. Epub 2025 Feb 12.
Deformation twinning, a phenomenon primarily documented within metallic systems, has remained essentially unexplored in covalent materials due to the formidable challenges posed by their inherent extreme hardness and brittleness. Here, by employing a five-degree-of-freedom nano-manipulation stage inside a transmission electron microscope, we reveal a loading-specific twinning criterion for cubic boron nitride and successfully activate extensive deformation twinning with substantial improvements in mechanical properties in <100>-oriented cubic boron nitride submicrometre pillars at room temperature. Beyond cubic boron nitride, this criterion is also proven widely applicable across a spectrum of covalent materials. Investigations on the twinning dynamics at the atomic level in cubic boron nitride suggest a continuous-transition-mediated pathway. These findings substantially advance our comprehension of twinning mechanisms in covalent face-centred cubic materials, and herald a promising avenue for microstructural engineering aimed at enhancing the strength and toughness of these materials in their applications.
形变孪晶是一种主要在金属体系中被记录的现象，由于共价材料固有的极高硬度和脆性带来的巨大挑战，在共价材料中基本未被探索。在此，通过在透射电子显微镜内使用五自由度纳米操纵平台，我们揭示了立方氮化硼的加载特定孪晶准则，并成功激活了广泛的形变孪晶，使<100>取向的立方氮化硼亚微米柱在室温下的力学性能有了显著改善。除了立方氮化硼，该准则还被证明广泛适用于一系列共价材料。对立方氮化硼中原子水平的孪晶动力学的研究表明了一种连续转变介导的途径。这些发现极大地推进了我们对共价面心立方材料中孪晶机制的理解，并为旨在提高这些材料在应用中的强度和韧性的微观结构工程开辟了一条有前景的途径。
