Molecular dynamics analysis of the effect of temperature on the internal structure transformation of polycrystalline 3 C-SiC nanoindentation

Abstract

To investigate the structure changes of polycrystalline 3 C-SiC nanoindentation process and the influence of temperature effect on its changes, the nanoindentation experiments of polycrystalline 3 C-SiC are constructed by molecular dynamics method. The initial nanoindentation model of polycrystalline 3 C-SiC and diamond indenter is constructed based on the characteristics of Voronoi method in constructing close-packed spatial lattice. The temperature conditions of 300 K, 500 K, 800 K and 1000 K are selected to analyze the dislocation structure, number and length, internal atomic structure, grain boundary structure and deformation degree of polycrystalline 3 C-SiC during nano-indentation process. The stress and deformation of diamond indenter are analyzed. The results show that the higher the temperature, the higher the degree of dislocation stacking. Temperature has an effect on the internal variation of polycrystalline silicon carbide, particularly on the transverse size of the structure. The central force of the diamond becomes weaker and the force on either side becomes stronger. The temperature effect can change the stacking degree of dislocations, reduce the internal structure transformation rate of polycrystalline 3 C-SiC, and transform fewer discrete atoms and increase the number of cubic lattice atoms.