Molecular dynamics simulation of ion-implanted single-crystal 3C-SiC nano-indentation

Abstract

To improve the machinability of the brittle material 3C-SiC, a new method of ion implantation surface modification is proposed. Molecular dynamics simulations were employed to investigate the mechanical properties and defect evolution of ion-implanted single-crystal 3C-SiC under nano-indentation. The effects of implantation dose, implantation energy, and implantation angle on the force, dislocation, hardness, and elastic modulus were discussed. The results revealed that ion implantation can reduce the hardness and elastic modulus, and improve the plasticity. Besides, the nucleation of dislocation is suppressed by ion implantation. It showed that the higher the implantation dose, the lower the force, the lower the hardness and elastic modulus, whereas those of implantation energy were the opposite. Therefore, the optimum implantation dose and energy can be obtained by comparing the above characteristics. Moreover, the channel effect was revealed under different implantation angles. Finally, through theoretical model analysis, it demonstrated that ion implantation affects the direction and size of normal stress. Thus, this method is favorable to material advanced manufacturing processes for enhancing the plasticity of the brittle single-crystal SiC.