Energetic design of grain boundary networks for toughening of nanocrystalline oxides
Energetic design of grain boundary networks for toughening of nanocrystalline oxides
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DOI：
10.1016/j.jeurceramsoc.2018.05.007
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发表时间：
2018-09-01
影响因子：
5.7
通讯作者：
Castro, Ricardo H. R.
中科院分区：
文献类型：
--
作者：
Bokov, Arseniy;Zhang, Shenli;Castro, Ricardo H. R.
提高纳米晶功能氧化物的机械性能对电池阴极的稳定性和弹性、可靠的核氧化物燃料的开发以及坚固耐用的催化载体具有重大影响。通过结合蒙特卡罗模拟、实验热力学和原位透射电子显微镜，我们展示了一种基于晶界热化学和裂纹扩展之间相互作用的新型增韧机制。通过使用氧化锆作为模型材料，镧在晶界偏析可提高各个晶界的韧性，同时促进更平滑的能量景观，其中裂纹通过晶界网络经历多次偏转，最终提高断裂韧性。
Improving the mechanical performance of nanocrystalline functional oxides can have major implications for stability and resilience of battery cathodes, development of reliable nuclear oxide fuels, strong and durable catalytic supports. By combining Monte Carlo simulations, experimental thermodynamics, and in-situ transmission electron microscopy, we demonstrate a novel toughening mechanism based on interplay between the thermo-chemistry of the grain boundaries and crack propagation. By using zirconia as a model material, lanthanum segregation to the grain boundaries was used to increase the toughness of individual boundaries and simultaneously promote a smoother energy landscape in which cracks experience multiple deflections through the grain boundary network, ultimately improving fracture toughness.