辐照环境空位流导致的非平衡态晶界力学行为研究

项目名称： 辐照环境空位流导致的非平衡态晶界力学行为研究

项目编号： No.11502191

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 郁汶山

作者单位： 西安交通大学

项目金额： 25万元

中文摘要： 提高辐照环境(如太空和核动力装备等)中材料的耐辐射性能，关键在于考虑如何降低材料内部受辐照产生的缺陷浓度。本项目拟以<110> 和<100>倾斜轴倾斜Cu晶界为研究对象，借助分子动力学模拟手段，系统地分析空位流作用下晶界的特征参量，包括晶界能量、体积、结构演化和空位形成能等，并揭示参量彼此间的关联性。进一步探究空位流加载中生成的一系列平衡态与非平衡态晶界，在室温下受拉伸和简单剪切载荷作用下的力学响应。阐明不同状态晶界的初始屈服应力、变形机理和耦合剪切迁移模式等的变化趋势，分析这些变化趋势与晶界特征参量之间的关系，探求其中的规律性和特殊性。本项目通过揭示Cu倾斜晶界对空位的吸收效率和机理，对耐辐照材料的设计和改性具有良好的工程意义，此外，平衡态和非平衡态晶界力学行为分析对剧烈塑性变形材料中晶界性质的研究也具有指导意义。

中文关键词： 空位；吸收效率；平衡态晶界；非平衡态晶界；力学行为

英文摘要： To enhance the ability of irradiation resistance of the materials in the aerospace and nuclear power equipment, it is vital to reduce the concentration of point defects produced from irradiations. The current proposed project will target the Cu GBs with <110> and <100> tilt axis. Using the molecular dynamics (MD) simulation approach, the characteristic properties of GBs upon a continuous vacancy flux loading, such as GB energy, GB excess volume, evolvement of structure and minimum vacancy formation energy in GB, will be systematically analyzed to reveal the correlation between these characteristic properties .Furthermore, the tensile and shearing mechanical properties of a series of equilibrated and non-equilibrated GBs produced from the vacancy flux loading history will be thoroughly studied at the room temperature. The analysis will be focused on not only the variation trend of the initial yield stresses, deformation mechanisms and changes of shear-coupling mode for a GB at different states, but the their correlations with GB characteristics. The research not only possesses high academic significance for the deep analysis of vacancy sink efficiency of <110> and <100> tilt Cu GBs, but also has an engineering significance for designing and improving preformation of the material with irradiation resistance. Moreover, the mechanical behavior analysis of equilibrated and non-equilibrated GBs is significant and instructive for investigating the properties of GBs in the materials suffering from severe plastic deformation (SPD).

英文关键词： Vacancy;Sink efficiency;Equilibrated grain boundary;Non-equilibrated grain boundary;Mechanical behavior