Effect of the point defect of silicon carbide cladding on mechanical properties: a molecular-dynamics study

We performed first principles calculations to study silicon carbide (SiC) crystal structure of mechanical with five interatomic potentials. We calculate elastic constants, bulk, shear, Young’s moduli, hardness, and Poisson’s ratio for polytypes of SiC. For each property, we report perfect and deformity crystal structures. In perfect condition, we appear the cubic structure (3C) is the most steady than hexagonal structures (4H, 6H). We compare interatomic potentials for structural parameters, formation energy, and elastic constants. Among potentials Edip, Meam, Tersoff 2005, and Vashishta are the most excellent results in lattice parameters, cohesive energy, density, and cell volume. Additionally, Tersoff 2005 is a better potential for elastic properties and formation energy calculation. We follow our calculations by investigating the brittleness/ductility of SiC by calculating Stability conditions, Cauchy’s pressure, Pugh’s ratio, and hardness. Among mechanical properties, we find out less stability in the point defect effect on hexagonal structures. The calculated results indicate that silicon vacancy has more rate in the mechanical properties; however, the C 44 , bulk shear, and Young’s modulus are comparable to higher changing within the three types of SiC structures. In the random vacancy of SiC, C 11 , and C 12 have a swing than carbon and silicon vacancies. Moreover, we demonstrate that carbon vacancy has a higher range than other vacancies.