Nanotwins soften boron-rich boron carbide (B13C2)
Nanotwins soften boron-rich boron carbide (B13C2)
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DOI：
10.1063/1.4978644
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发表时间：
2017-03-13
影响因子：
4
通讯作者：
Goddard, William A., III
中科院分区：
文献类型：
--
作者：
An, Qi;Goddard, William A., III
对金属和合金的广泛研究发现，纳米孪晶可以增强强度，但纳米孪晶在陶瓷中的作用尚未明确。我们在这里比较了纳米孪晶富硼碳化硼（B13C2）与完美晶体在纯剪切和双轴剪切变形下的剪切强度和变形机制。我们发现晶体 B13C2 的固有剪切强度高于晶体碳化硼 (B4C)。但 B13C2 中的纳米孪晶降低了强度，使其比结晶 B4C 更软。纳米孪晶 B13C2 强度的降低是由于孪晶边界与连接 B-12 二十面体的 C-B-C 链的相互作用所致。由 AIP 出版社出版。
Extensive studies of metals and alloys have observed that nanotwins lead to strengthening, but the role of nanotwins in ceramics is not well established. We compare here the shear strength and the deformation mechanism of nanotwinned boron-rich boron carbide (B13C2) with the perfect crystal under both pure shear and biaxial shear deformations. We find that the intrinsic shear strength of crystalline B13C2 is higher than that of crystalline boron carbide (B4C). But nanotwins in B13C2 lower the strength, making it softer than crystalline B4C. This reduction in strength of nanotwinned B13C2 arises from the interaction of the twin boundary with the C-B-C chains that connect the B-12 icosahedra. Published by AIP Publishing.