Numerical study of three-body diamond abrasive nanoindentation of single-crystal Si by molecular dynamics simulation

摘要

Exploring the accuracy of nanoindentation testing is especially important for determining the hardness and Young's modulus values of materials. In this paper, molecular dynamics simulation was used to study the nanoindentation mechanism of three-body diamond abrasive grains rotating at various speeds on single-crystal silicon materials. An in-depth study of the three-body diamond abrasive nanoindentation single-crystal Si process, indentation stress, dislocation, crack propagation, coordination number, defect atoms, load, nanoindentation zone temperature, and potential energy changes is made. The results mean that the smaller the speed of rotation of the three-body abrasive grains, the greater the stress in all directions, and the more the dislocations that can be easily observed inside the workpiece. Moreover, the greater the rotational speed of the abrasive grains, the smaller the number of Si-II phase transitions in the workpiece; the number of defective atoms inside the workpiece after the three-body abrasive nanoindentation is greater than that in the case of two-body abrasive nanoindentation. In addition, the faster the abrasive grain rotation, the higher the temperature of the workpiece nanoindentation zone, the larger the potential energy, the more obvious the atomic motion inside the workpiece, and the greater the atomic motion inside the workpiece is biased toward the direction of rotation. In addition, the faster the grain rotation in three-body nanoindentation, the smaller the average load on the workpiece.