Velocity-dependent Nanoscratching of Amorphous Polystyrene

In current work, we perform molecular dynamics simulations to investigate the effect of machining velocity on the nanoscratching of amorphous polystyrene. In particular, the deformation mechanisms of the material are analyzed and are related to its frictional response. Simulation results reveal that inter-chain sliding and intra-chain change are two competing deformation mechanisms governing the permanent deformation of polystyrene specimen. Furthermore, quantitative characterization of dihedral angle evolution indicates that intra-chain change is more energetically stable than inter-chain sliding. It is found that the deformation behavior of polystyrene specimen under nanoscratching strongly depends on machining velocity, which subsequently affects scratching results.