论文标题
多尺度和多物理框架，用于模拟纳米晶体材料中的辐射损伤
A multiscale and multiphysics framework to simulate radiation damage in nano-crystalline materials
论文作者
论文摘要
这项工作提出了一个多尺度和多物理框架，以研究纳米晶体材料中辐射诱导的损伤。该框架结合了两种方法，包括分子动力学模拟，具有电子效应和纳米晶体材料中的长期原子扩散模拟。使用此框架，我们研究了辐射事件下的纳米结晶材料的自我修复行为。我们发现，在级联模拟过程中，在纳米晶体中产生的缺陷数量小于单晶。这种行为是由于级联模拟过程中晶界网络中间质原子的快速吸收，而空位比间隙原子更长的时间尺度迁移到边界。因此，纳米结晶材料显示出一种自我修复行为，其中缺陷的数量和大小随时间而大大减少。我们发现，纳米晶体材料的自我修复行为受到限制，约有50％的空缺生存。这种效果是由于空缺的集体行为群而产生的，这些行为比单个空缺要稳定得多。
This work presents a multiscale and multiphysics framework to investigate the radiation-induced damage in nano-crystalline materials. The framework combines two methodologies, including molecular dynamics simulations with electronic effects and long-term atomistic diffusion simulations in nano-crystalline materials. Using this framework, we investigated nano-crystalline materials' self-healing behavior under radiation events. We found that the number of defects generated in nano-crystals during the cascade simulations was less than in single crystals. This behavior was due to the fast absorption of interstitial atoms in the grain boundary network during the cascade simulations, while vacancies migrated to the boundaries in a much longer time scale than interstitial atoms. Thus, nano-crystalline materials showed a self-healing behavior where the number and size of the defects are drastically reduced with time. We found that the self-healing behavior of nano-crystalline materials is limited, and about 50% of vacancies survived. This effect resulted from clusters of vacancies' collective behavior, which are much more stable than individual vacancies.
