Effect of graphene on the surface nanomechanical behavior and subsurface layer of GaN damage during nanogrinding using molecular dynamics simulation

Molecular dynamics simulations were used to investigate the surface nanomechanical behavior and subsurface layer damage of gallium nitride (GaN)/graphene composites when subjected to nanogrinding with diamond abrasive. The effects of graphene on GaN were analyzed based on parameters such as atomic displacement, forces, crystal structure, subsurface damage, atomic stress, and temperature. The simulation results indicate that graphene has a noteworthy impact on the surface morphology, such as the pile-up atoms on the workpiece surface and the elastic recovery on the machined surface. In addition, the addition of graphene can reduce the atomic temperature, stress, and normal and tangential forces. In terms of subsurface damage formation, graphene can suppress lattice damage and amorphization of GaN during nanogrinding. The addition of graphene can significantly reduce the dislocation length and the phase transition from wurtzite to a five-fold coordination hexagonal structure. Overall, the addition of graphene can improve the deformation mechanism on the GaN surfaces. This study provides technical references for the design of GaN with improved friction and wear resistance.