碳微球的纳米压痕弹塑性行为的研究

Research on nano-indentation elastic-plastic behavior of carbon microspheres

通过光学显微镜和原子力显微镜观察到碳微球的结构,采用纳米压痕法研究碳微球的压痕弹塑性行为以及基体效应,分析了载荷作用下最大压痕深度、弹性回弹量、弹性能和弹性回复率等弹性性能。研究表明:碳微球在最大压痕深度与微球半径的比值(h_m/R)超过0.1时,其压痕行为受到基体的影响,在载荷为75μN下,h_m/R为0.16~0.17时,所测得的接触弹性模量值误差将接近50%,并随着载荷的增加,h_m/R增加,误差也随之增加;碳球的回弹率和弹性回复能力随着载荷的增加而下降,说明在较高载荷下产生了较大的不可回复的塑性变形和储存了较大的弹塑性能。

The micrographs of carbon microspheres(CMSs)were observed under an optical microscope and atomic force microscopy.The indentation elastic-plastic behavior and the effect of the substrate on it were studied by the nano-indentation method.The elastic properties of the maximum indentation depth,the elastic recovery,the elastic energy and the ratio of the elastic energy to the total energy were analyzed.The experimental results show that the indentation behavior is influenced by the substrate when the ratio of the maximum indentation depth to the radius(hm/R)of CMSs is more than 0.1.The error of the measured contact modulus will reach at 50%while hm/R arrives 0.16~0.17 under the load 75 N.The error will continue to increase with the increasing of the h_m/R and the load.The ratio of the recovery to the maximum and the ratio of the elastic energy to the total energy decrease with the increasing of the load,suggesting that the CMSs produce higher plastic deformation and store more plastic energy.