Molecular dynamics analysis of temperature effects on nanoindentation measurement

A three-dimensional molecular dynamics (MD) model is carried out to study the effects of temperature on the atomic-scale nanoindentation process. The model utilizes the Morse potential function to simulate interatomic forces between the sample and tool. The results show that both Young's modulus and hardness become smaller as temperature increases. The results also indicate that elastic recovery is smaller at higher temperatures. The softening behavior is similar to the prior experiment and the estimated elastic moduli are much higher than the prior experiment. The discrepancy may be due to simulations performed on defect-free single crystals. In addition, some defects of vacancies, atomic steps and plastic indent are observed on the surface region. (C) 2003 Elsevier Science B.V. All rights reserved.