分子动力学研究两种准晶中的辐照级联过程

项目名称： 分子动力学研究两种准晶中的辐照级联过程

项目编号： No.11305147

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 陈丕恒

作者单位： 中国工程物理研究院

项目金额： 30万元

中文摘要： 对称性对材料的辐照损伤行为有重要影响，弄清对称性与辐照效应之间的关联对抗辐照材料设计、辐照改性工艺设计等具有重要意义。过去的研究主要集中在晶体中的辐照效应，有关准晶辐照效应的研究鲜见报道。准晶与晶体之间对称性的区别远大于晶体之间的区别，通过准晶和晶体之间的对比研究更有助于深入理解对称性与辐照效应之间的关联。本项目拟以CaCd二元准晶和AlCoNi三元准晶为例，采用分子动力学方法研究准晶及其近似体中的辐照级联过程。重点研究对称性对离位阈能、次级级联阈能的影响；获得温度、初始动能对级联过程的影响规律；并将其结果与Ca、Cd、Al、Co、Ni纯元素晶体中的辐照损伤行为进行对比，讨论对称性对级联过程的影响。研究结果有助于深入理解材料结构与辐照效应之间的关联，并有可能揭示若干新的物理机制。

中文关键词： 分子动力学；准晶；辐照损伤；对称性；

英文摘要： Symmetry of crystal structure has a strong influence on many aspects of damage production,while other material characteristics are of lesser overall importance. The defects created in cascade damages and their subsequent evolution gives rise to important changes in the engineering properties of materials, so it is crucial to understanding and predicting these for assessing lifetime of material in irradiation environments. Until the relationship between structures and radiation damages is clarified, the goal of predicting the evolution of damage in materials used in such technologies as nuclear power generation and surface modification will remain largely unrealized. In the past years, many works have been done on cascade simulation in crystallines, while little work has been done in quasicrystals due to their complex structures. Comparison between displacement cascade in crystallines and quasicrystals may help to understand the relationship between structures and radiation damages for their big difference in symmetries. In this project, molecular dynamics simulations of collision cascades in CaCd and AlCoNi quasicrystals and their approximants will be performed . Effect of local order structures on displacement threshold energy surfaces and energy dependence of defect production will be studied and compared

英文关键词： Molecular dynamics；Quasicrystal；Radiation damage；Symmetry；