Intrusion Simulation of a C60 Ball into Sliding Contact Space with Graphene Layered Surfaces

The intrusion process of a C60 molecular ball into a sliding contact space with garaphene layered surfaces was simulated using the Molecular Dynamic approach.The contact space was made up by two silicon substrates with graphene layered on the surface of the upper substrate forming an included angle which was defined as initial entry angle changing from 20°to 90°.Then a linear velocity of 30/ps was applied to the lower substrate along horizontal direction.The simulation was carried out using Tesoff potential of C and Si atoms at room temperature 300K.The simulation results showed that when the intrusion angle exceeded a critical angle of 80°,the C60 ball could not intrude the contact space,and the number of the sticking atoms sharply increased.Also,the dependence of maximum pull-off force acting on the upper substrate on the initial entry angle during the C60 intrusion process was calculated in which the critical force for C60 intrusion is found.All the results showed that the upper silicon substrate was well protected by the mono graphene layer.