Abstract Yttria-stabilized zirconia (YSZ) used as the electrolyte in solid oxide fuel cells usually relies on the complicated chemical reactions at an extremely high temperature. In this paper, the impact of the reaction on the mechanical properties of YSZ is investigated with the aid of reactive force-field (ReaxFF) molecular dynamics simulations. The obtained results show that before the reaction, the intrinsic Young's modulus of YSZ is almost independent of the crystal orientation, while different Poisson's ratios are detected in different crystal orientations. After the reaction, both Young's modulus and Poisson's ratio of YSZ are greatly reduced, since the oxygen in the surface can be deboned and thus escapes from YSZ. Specifically, the largest difference of the mechanical properties before and after the reaction is observed in [111]-oriented YSZ, since it has a unique zigzag surface structure. A decrease of Young's modulus and Poisson's ratio is also observed in YSZ with increasing the temperature and the doping concentration, though the reduction in the mechanical properties is different in different crystal orientations. Based on the obtained simulation results, predictive equations were proposed for quickly predicting the Young's modulus and the Poisson's ratio of YSZ at different temperatures and with different doping concentrations.

中文翻译：

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氧化钇稳定氧化锆的机械性能：ReaxFF 分子动力学模拟研究

摘要 在固体氧化物燃料电池中用作电解质的氧化钇稳定氧化锆（YSZ）通常依赖于在极高温度下的复杂化学反应。在本文中，借助反应力场 (ReaxFF) 分子动力学模拟研究了反应对 YSZ 机械性能的影响。得到的结果表明，在反应前，YSZ 的固有杨氏模量几乎与晶体取向无关，而在不同的晶体取向上检测到不同的泊松比。反应后，YSZ 的杨氏模量和泊松比都大大降低，因为表面的氧可以脱骨，从而从 YSZ 中逸出。具体来说，在[111]取向的YSZ中观察到反应前后机械性能的最大差异，因为它具有独特的锯齿形表面结构。随着温度和掺杂浓度的增加，在 YSZ 中也观察到杨氏模量和泊松比的降低，尽管不同晶体取向的机械性能降低不同。根据获得的仿真结果，提出了快速预测不同温度和不同掺杂浓度下YSZ的杨氏模量和泊松比的预测方程。尽管在不同的晶体取向下机械性能的降低是不同的。根据获得的仿真结果，提出了快速预测不同温度和不同掺杂浓度下YSZ的杨氏模量和泊松比的预测方程。尽管在不同的晶体取向下机械性能的降低是不同的。根据获得的仿真结果，提出了快速预测不同温度和不同掺杂浓度下YSZ的杨氏模量和泊松比的预测方程。