多晶体材料微构件尺度效应的实验和模型研究

Research on the Scale Effect of Micro-Components of Polycrystalline Materials Based on Experiments and Theoretical Models

归纳了微电子机械系统中多晶体材料微构件在微塑性加工和应用中其力学性能所表现出来的尺度效应及其多种尺寸关联的主要特征,介绍了微构件外形几何尺寸和材料内部微结构尺寸对其弹、塑性力学性能尺度效应耦合影响的实验和模型研究的主要进展。重点总结并分析了多晶体材料微构件越小越强和越小越弱两种类型尺度效应的研究方法以及测试、影响因素及微观机理初步分析的结果。结论是:微构件内、外尺寸的耦合关联影响控制了尺度效应和与其相对应的材料内在特征长度,今后如能进一步探明微构件外形结构尺寸、晶粒尺寸和材料内在特征长度与其性能异变之间的制约关系,基于晶体学和高阶理论建立较全面、系统的力学分析模型,将有可能揭示微构件多晶材料内在特征长度的微结构控制的机理,进而实现通过调控材料的微结构控制微构件的宏观力学性能。

The scale effect, as well as its relevant characteristics of many sizes of mechanical properties of the polycrystalline material micro-components in micro-electro-mechanical systems are summarized. The coupled influence of geometric shape and the size of internal microstructure of the micro-components on their elastic and plastic properties researched through experiments and theoretical models are also introduced. The main research methods, test results, influencing factors and the micro-mechanism of two types of scale effects, namely, ＂smaller is stronger＂ and ＂the smaller the more weak＂, occurred in micro-components of polycrystalline materials are particularly summarized. The conclusions can be described as follows： the coupling effects of the inner and outer dimensions of micro-components may directly control scale effects and their corresponding material intrinsic characteristic length. In the future, the quantitative relationships of the size of geometry structure, grain size, as well as intrinsic characteristic length of micro-component and the changes of mechanical properties will be explored further. Based on crystallography and higher-order theory, the completed and systemic mechanics analysis model is built, it would be possible to reveal the mechanism that micro-structure controls intrinsic characteristic length of micro-component materials. Accordingly, the macro-mechanical properties of microcomponent can be controlled by changing the material micro-structure.