【摘要】 针对微纳米尺度下材料硬度测试中出现的压痕尺寸效应(ISE),指出目前用于解释压痕尺寸效应较为常用理论方法;介绍了应变梯度塑性理论的发展过程,引入了几何必需位错密度的概念,详细地描述了Nix-Gao模型及其修正模型的产生,对于预测硬度随压痕深度的变化趋势提供了很好的预测;介绍了能量平衡方法的形成过程,通过描述Meyer方程、Hays-Kendall方法和比例试样阻力模型,推导出能量平衡方程,为分析试验结果提供了理论模型;通过理论公式推导,分析两种理论分析方法对于压痕尺寸效应分析的一致性.更多还原

【Abstract】 The theories generally used to interpret the indentation size effect(ISE) observed in hardness measurement at micro/nano scale are presented.The progress of micro-mechanism based strain gradient plasticity theory is introduced and a new concept of geometrically necessary dislocations density is brought forward.The Nix-Gao model and its modification,which can predict the trend of hardness with indentation depth’s change,are described in detail. The progress of energy balance approach which gives a theoretical model for the analysis of experiments results is introduced too.The energy balance equation is deduced by analyzing Meyer’s law,Hays-Kendall approach and proportional specimen resistance model.After reasoning,consistency between these two theories is pointed out.更多还原