Xu Haiyue, Ji Wei, Jiang Jiawei, Liu Junliang, Wang Hao, Zhang Fan, Yu Ruohan, Tu Bingtian, Zhang Jinyong, Zou Ji, Wang Weimin, Wu Jinsong, Fu Zhengyi
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, China.
Department of Materials, University of Oxford, Oxford, OX1 3PH, UK.
Nat Commun. 2023 Aug 21;14(1):4889. doi: 10.1038/s41467-023-40581-7.
The improvement of non-oxide ceramic plasticity while maintaining the high-temperature strength is a great challenge through the classical strategy, which generally includes decreasing grain size to several nanometers or adding ductile binder phase. Here, we report that the plasticity of fully dense boron carbide (BC) is greatly enhanced due to the boundary non-stoichiometry induced by high-pressure sintering technology. The effect decreases the plastic deformation temperature of BC by 200 °C compared to that of conventionally-sintered specimens. Promoted grain boundary diffusion is found to enhance grain boundary sliding, which dominate the lower-temperature plasticity. In addition, the as-produced specimen maintains extraordinary strength before the occurrence of plasticity. The study provides an efficient strategy by boundary chemical change to facilitate the plasticity of ceramic materials.
在保持高温强度的同时提高非氧化物陶瓷的可塑性是一个巨大的挑战，传统策略通常包括将晶粒尺寸减小到几纳米或添加韧性粘结相。在此，我们报道了由于高压烧结技术引起的边界非化学计量比，完全致密的碳化硼（BC）的可塑性得到了极大增强。与传统烧结试样相比，这种效应使BC的塑性变形温度降低了200°C。促进的晶界扩散被发现可增强晶界滑动，这主导了低温可塑性。此外，所制备的试样在发生塑性之前保持了非凡的强度。该研究提供了一种通过边界化学变化来促进陶瓷材料可塑性的有效策略。
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