Study on the deformation mechanism of spherical diamond indenter and its influence on 3C-SiC sample during nanoindentation process via molecular dynamics simulation

Abstract

Diamond indenters are usually regarded undeformable during nanoindentation process. However, when the sample to be indented is very hard material, the deformation of indenters should not be neglected. In order to study the effect of deformation of indenters, a study through molecular dynamics (MD) method is conducted. Deformable and rigid spherical diamond indenters are applied to indent on 3C-SiC sample. According to the simulation results, spherical indenter shows complicated deformation. The indenter is compressed during the early stage of loading process, and has a little recovery latterly. This kind of deformation largely influences the onset and development of dislocations of 3C-SiC sample during nanoindentation process. The deformation of indenter can also result in the inaccuracy measurement of actual indentation depth and hardness. In addition, load-indentation depth curves and hardness-indentation depth curves show that both of the calculated indentation force and hardness are smaller when the indenter deforms. Moreover, a correction method is put forward in this paper to eliminate the influence of deformation of spherical indenter. This research provides new insights to perfect theoretical system of nanoindentation.