纳米颗粒和纳米柱体的力学行为研究

项目名称： 纳米颗粒和纳米柱体的力学行为研究

项目编号： No.11272249

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 王刚锋

作者单位： 西安交通大学

项目金额： 78万元

中文摘要： 纳米颗粒和纳米柱体是组装纳米器件和合成纳米材料的基本单元。由于表面所占比例显著增加，纳米颗粒和纳米柱体的弹性模量、屈服应力和塑性变形机制等明显不同于宏观块体材料，表现出显著的尺度相关性。本项目将采用理论分析、分子动力学模拟和微纳米尺度实验相结合的方法来研究纳米颗粒和纳米柱体的弹塑性力学行为。我们将基于表面弹性和晶体各向异性来研究单晶纳米颗粒和纳米柱体的弹性变形。建立纳米颗粒和纳米柱体的屈服应力与晶体结构、外在尺寸和加载方向的定量关系。采用分子动力学模拟方法揭示纳米颗粒和纳米柱体的塑性变形机制。研究周期载荷作用下纳米颗粒和纳米柱体的疲劳特性。利用AFM和STM等开展纳米尺度实验，测试纳米颗粒和纳米柱体的压缩变形过程和疲劳曲线。本项目的开展将能够用于纳米颗粒和纳米柱体力学性能的测试和评估、及其弹塑性力学响应的描述，对纳米器件和系统的设计与制备提供重要的指导意义。

中文关键词： 纳米颗粒；弹性；塑形；接触力学；

英文摘要： Nanoparticles and nanopillars are the fundamental building blocks of advanced nanosystems and nanocomposites. Owing to the greately increased ratio of surface area to volume, their mechanical properties like elastic modulus, yield stress and plastic deformation mechanism display evident size dependence, which are clearly distinct from their macroscopic counterparts. In this porject, theoretical analysis,atomic simulation and nanoscale elaborate experiment will be performed to investigate the elastic and plastic deformation of nanoparticles and nanopillars. Based on the surface elasticity and crystal anisotropicity, we will analyze the elastic response of nanoparticles and nanopillars. It is expected to found the dependence of the yield stress on the intrinsic cystalline structure, extrinsic geometry and loading direction. Atomic simulations will be employed to explore the micro-mechanism of plasticity of nanoparticles and nanopillars. We will also investigate the fatigure characteristics of nanoparticles and nanopillars under cycle loading. Based on AFM and STM, the compression of nanoparticles and nanopillars, as well as the fatigure curve, will be measured. These works will be helpful to measure and evaluate the mechanical properties of nanoparticles and nanopillars, and describe their elasti and plastic defor

英文关键词： nanoparticle；elasticity；plasticity；contact mechanics；