Effect of Nanoindentation Temperature on Plastic Deformation of 3C‐SiC Based on the Molecular Dynamics Method

Abstract

To explore the effect of nanoindentation temperature on the plastic deformation of 3C‐SiC, it is possible to analyze the 3C‐SiC load‐displacement changes at different temperatures and the dislocation propagation in the plastic deformation stage. The 3C‐SiC nanoindentation model is established on the basis of molecular dynamics interatomic interaction potential. The model combines the 3C‐SiC crystal structure to optimize the Vashishta potential function and modifies the relaxation system, system boundary, and other simulated environmental factors. The plastic deformation process of 3C‐SiC at different temperatures is analyzed from multiple angles such as the load‐displacement curve, the stress distribution during the plastic deformation stage of the matrix, and the formation and growth of specimen dislocations. During the pressing process, intermolecular dislocations and stress are concentrated in the elastic‐plastic deformation zone. The load value of the elastic‐plastic deformation zone under high temperature environment is generally higher, and the energy of the dislocation loop will be released. In the plastic deformation zone, the dislocation loop will break under the action of high temperature environmental load. The premature release of energy will cause the load value to drop. During the pressing process, the bearing capacity of 3C‐SiC polycrystalline will decrease as the temperature rises. Plastic deformation occurs inside the material, and dislocations nucleate and expand from the grain boundary to the crystal and finally form a U‐shaped dislocation ring.