非晶合金结构单元的特征及其与形变和弛豫关系的模拟研究

项目名称： 非晶合金结构单元的特征及其与形变和弛豫关系的模拟研究

项目编号： No.51271197

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 一般工业技术

项目作者： 李茂枝

作者单位： 中国人民大学

项目金额： 90万元

中文摘要： 大块非晶合金材料和物理研究的快速发展使得人们越来越关注非晶合金中的基本物理问题，以便更有效地指导新材料的探索和改善。非晶合金结构无序，缺乏明显的微观结构特征，能量亚稳，宏观性能与原子结构的跨尺度等特征，使得从理论到实验上表征和建立结构与性能的相关性极其困难。在对微观结构特征没有充分认识的情况下，寻找一条进一步研究和探索非晶合金形变和弛豫微观机理的出路，对我们深入认识和理解非晶合金中的物理问题是非常迫切的。非晶合金中的弛豫和形变都是一种流变行为，是在温度或应力的激发下具有某些共同特征的微观结构单元发生不可逆原子重组，形成基本流变单元，实现结构弛豫或形变。本项目拟采用分子动力学方法研究在外界作用的激发下，非晶合金中微观结构单元的不同响应，从而表征基本流变单元的性质和特征，研究基本流变单元的激发、演化以及与宏观性能的相关性，发展非晶合金流变单元模型，进一步认识非晶合金形变机制和玻璃转变的本质。

中文关键词： 金属玻璃；流变单元；分子动力学；弛豫；形变

英文摘要： With the development of bulk metallic glasses (MGs), the fundamental issues in MGs have been paid more and more attention for exploring new materials. MGs are structually disordered and metastable. There are several order between macroscopic properties and atomic structures. All these make it difficult to characterize the relationship between structures and properties. Therefore, it is crucial to find a new way to inevstigate the deformation and relaxation mechanisms for better understanding the fundamental issues in MGs. In MGs relaxation and deformation are both flow behavior, which are stimulated by temperature or external stress and realized in terms of local atomic rearrangements, the so-called flow units. In relaxation or deformation in MGs, the characteristics of flow units are key to the understanding of deformation mechamisms and glass transition. In this proposal, we will perform molecular dynamics studies for the various response of the atomic structures in MGs under temperature or external stress. Then we may characterize the properties and features of flow units, investigate the excitation and evolution of the flow units as well as its relationship with properties. Based on the above research, we will try to devlop theoretical model of flow units in MGs and get deeper insight into the deformation me

英文关键词： metallic glasses；flow unit；molecular dynamics simulation；relaxation；deformation