纳米金属微观结构不稳定性机理的三维研究

项目名称： 纳米金属微观结构不稳定性机理的三维研究

项目编号： No.51471039

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 一般工业技术

项目作者： 吴桂林

作者单位： 重庆大学

项目金额： 80万元

中文摘要： 纳米金属具有高强度、高疲劳性能和良好导电性，使其作为结构材料和在微纳电子行业都具有良好的应用前景，但是对于纳米金属的一些核心问题，如其微观结构稳定性(在受热或应力作用下的晶粒长大行为)还有待深入研究，这就要求对纳米金属微观结构参数（晶粒的形状、大小、位置和晶体学取向、晶粒间的位向关系和拓扑连接关系、晶界的曲率和法线及分布、杂质元素或合金元素的分布）及其演变的三维精确定量表征。本研究将以最新的基于透射电子显微镜的三维晶粒取向重构技术(3D-OMiTEM)和三维原子探针（3D-APT）为主要研究手段，以纳米金属Ni和Ni-W合金为研究对象，对纳米金属的微观结构不稳定性机理以及固溶元素的影响进行深入的研究，探讨实现微观结构稳定化的途径。

中文关键词： 微观结构不稳定性；纳米金属；三维透射电子显微镜；热稳定性；力学稳定性

英文摘要： Nanometals (defined as metals with grain sizes less than 100 nm) have a wide range of potential applications as structural materials in the fields of MEMS and NEMS. The microstructural instabilities under thermal and mechanical conditions (the grain grwoth phonomena under heat and stress) has been the central issues of nanometals. A complete understanding of the underlying mechanisms responsible for the microstructural stabilities requires a full characterization of 3D structural parameters (grain size, shape, location, crystallographic orientation, grain boundary curvature, boundary normal and their 3D distribution, and 3D topological connectivity between grains; 3D distribution of solute elements/segregation) and their evolutions as a function of time, temperature or strain. This project will based on 3D characterizations of structural parameters and chemistry by means of 3D-OMiTEM (a newly developed TEM based technique with a spatial resolution of 1 nm) and 3D-APT (a well established 3D chemical mapping technique with atom resolution). The aims of the present study are to achieve new understanding of the underlying mechanisms for the microstructural stabilities of nanometals, and to explore approaches to stabilize the microstructure of nanometals.

英文关键词： microstructrue instability;Nanometals;3D-TEM;thermal stability;mechcnical stability