Twisted-layer boron nitride ceramic with high deformability and strength

• 成果类型: Article
• 署名作者: Wu, Yingju; Zhang, Yang; Wang, Xiaoyu; Hu, Wentao; Zhao, Song; Officer, Timothy; Luo, Kun; Tong, Ke; Du, Congcong; Zhang, Liqiang; Li, Baozhong; Zhuge, Zewen; Liang, Zitai; Ma, Mengdong; Nie, Anmin; Yu, Dongli; He, Julong; Liu, Zhongyuan; Xu, Bo; Wang, Yanbin; Zhao, Zhisheng; Tian, Yongjun
• 署名单位: Yanshan University; Tsinghua University; Shaanxi University of Technology; University of Chicago; Yanshan University
• 刊物名称: Nature
• ISSN/ISSBN: 0028-4198
• DOI: 10.1038/s41586-024-07036-5
• 发表日期: 2024-02-22
• 关键词: plastic-deformation; kink bands; pseudopotentials; ductile

摘要

Moire superlattices formed by twisted stacking in van der Waals materials have emerged as a new platform for exploring the physics of strongly correlated materials and other emergent phenomena1-5. However, there remains a lack of research on the mechanical properties of twisted-layer van der Waals materials, owing to a lack of suitable strategies for making three-dimensional bulk materials. Here we report the successful synthesis of a polycrystalline boron nitride bulk ceramic with high room-temperature deformability and strength. This ceramic, synthesized from an onion-like boron nitride nanoprecursor with conventional spark plasma sintering and hot-pressing sintering, consists of interlocked laminated nanoplates in which parallel laminae are stacked with varying twist angles. The compressive strain of this bulk ceramic can reach 14% before fracture, about one order of magnitude higher compared with traditional ceramics (less than 1% in general), whereas the compressive strength is about six times that of ordinary hexagonal boron nitride layered ceramics. The exceptional mechanical properties are due to a combination of the elevated intrinsic deformability of the twisted layering in the nanoplates and the three-dimensional interlocked architecture that restricts deformation from propagating across individual nanoplates. The advent of this twisted-layer boron nitride bulk ceramic opens a gate to the fabrication of highly deformable bulk ceramics. A bulk ceramic composed of interlocked boron nitride nanoplates with a laminated structure of twist-stacked nanoslices is created using hot-pressing and spark plasma sintering, which exhibits large elastic and plastic deformability and high strength at room temperature.