Micromechanics of surface deformation by Nanoindentation

压痕测试是通过使用安装在常规维氏压头或伯科维奇压头上的连续载荷深度传感系统进行的。使用载荷和位移传感压痕实验确定硬度的程序的合理性可能不能从基于弹性球腔模型的解析解中获得。在本研究中，我们假设压痕塑性为柱状位错环，在垂直于接触面的方向上具有Burgers矢量。根据卸载过程中的载荷-位移曲线和残余接触印痕的地形数据，我们通过求解反问题来估计诱发塑性核心区的形状和材料的屈服应力。对屈服应力和塑性核心区进行了预测。分析还确定了几何参数。

Indentation tests are conducted by using a continuous load-depth sensing system which is installed on a conventional Vickers indent or Bercovich indent. The justification of the procedure for determining hardness using load and displacement sensing indentation experiments may not be obtained from the analytical solutions based on the elastic spherical cavity model. In this study, we assume the indentation plasticity as prismatic dislocation loops with Burgers vectors in the direction normal to the contact surface. we estimate the configuration of the induced plastic core zone and the yield stress of the material by solving an inverse problem in terms of both the load-displacement curves during unloading and topographic data of the residual contact impression. We predicted the yield stress and plastic core zone. The analysis also determined the geometrical parameters.