Molecular Dynamics Investigation of β-SiC Behavior Under Three-Axial Tensile Loading

Molecular dynamics (MD) simulations were used to study the mechanical behaviour of beta-SiC at nano-scale under tensile loading. Effects of loading rate and tensile temperature on the mechanical properties and failure were studied. Modified embedded-atom method (MEAM) potential and Berendsen thermostat were utilized for modelling. Periodic boundary conditions were employed and the behaviour of material was analyzed under three-axial loading condition at which the stress-strain relation was acceptably size independent. It is shown that with increasing the loading rate from 5 m/s to 70 m/s, the failure strain increases without a remarkable change in the stress-strain relationship. The MD simulation plots at different temperatures reveal that beta-SiC exhibits highly brittle behaviour at low and moderate temperatures (< 1000 K) and more ductile behaviour with considerable structural transformations at the higher temperatures. According to the Hooke's law, the modulus of elasticity and poisson's ratio for beta-SiC at different temperatures are reported. Extrapolating of the acquired data to low loading rates, i.e., between 5 to 70 m/s to predict the behaviour of the material in more practical condition, revealed a convincing agreement with reported theoretical and experimental results.