Molecular dynamics analysis of effects of velocity and loading on the nanoindentation

Three-dimensional molecular dynamics (MD) simulation is used to investigate the atomistic mechanism of nanoindentation process under various indentation loads and velocities that occur when a diamond tip interacts with the copper thin film. In this study, the model utilizes the Morse potential function to simulate interatomic forces between the specimen and tip. The results show that both Young's modulus and hardness increase up to a critical value and decrease there after for the indentation velocities, but decrease as the indentation loads increase. In additional, the contact stress-strain relationship is shown to be important.