论文部分内容阅读
对压入深度为亚微米量级的微压痕实验来说 ,硬度与压入深度的关系将表现出强烈的尺度效应 ,然而 ,由传统的弹塑性理论无法预测 .采用塑性应变梯度理论对微压痕实验中的尺度效应进行预测 ;同时对单晶铜和单晶铝进行微压痕实验研究 .通过将理论预测结果应用于实验 ,获得塑性应变梯度理论中的微尺度参量值 ,该值对于常规金属材料 (如铜、铝、银等 )来说 ,取值范围为 0 .8～ 1 .5 μm .另外 ,对微压痕边界附近所出现的挤出现象 (pile up)和沉陷现象 (sink in)进行了预测和详细分析 .
For the indentation depth of submicrometer microindentation experiments, the relationship between hardness and press-in depth will show a strong scale effect, however, it can not be predicted by the traditional elasto-plastic theory.Using the theory of plastic strain gradient Scale effect in the indentation experiment is predicted.At the same time, micro-indentation experiments of single crystal copper and single crystal aluminum are carried out.Applying the theoretical prediction results to the experiment, the microscale parameter values in the plastic strain gradient theory are obtained, Conventional metallic materials (such as copper, aluminum, silver, etc.) range from 0.8 to 1.5 μm. In addition, pile up and sinking phenomena near the microindentation boundaries ( sink in) were predicted and analyzed in detail.