Molecular dynamics simulation of tension deformation in monocrystalline β-SiC bulk

Tension simulations of [001] monocrystalline face-centered cubic SiC (β-SiC) and C-doped β-SiC bulks are performed with molecular dynamics method to investigate intrinsic deformation mechanisms and mechanical behaviors of β-SiC under strain rates of 5 × 108/s, 1 × 109/s, 1 × 1010/s. It is found that Si-C sp3 and C-C sp3 bonds respectively transform to Si-C sp2 and C-C sp2 bonds as soon as the strains reach certain critical values. As certain amounts of sp2 bonds are formed, instable fractures emerge in β-SiC. Since C-C sp2 bonds are formed earlier than Si-C sp2 bonds, the doping of C elements leads to the decrease of strength, Young's modulus and tension fracture strain of β-SiC. In addition, it is found that the strain rates have effects on tensile-strength, but not on Young's modulus.