Frictional behaviour of silicon carbide (SiC) at the nanoscale using molecular dynamics (MD) simulations

Silicon carbide (SiC) is widely employed as a friction-pair material in high-load and extreme-service environments due to its superior wear resistance and high-temperature stability. However, continuum-based tribological models have limited capability in capturing interfacial deformation and material removal mechanisms at the atomic scale. In this work, molecular dynamics simulations were performed using LAMMPS and analysed/visualised with OVITO to investigate how temperature (300, 700, and 1100 K), penetration depth (10, 12, and 14 Å), and sliding velocity (0.2, 0.5, and 0.8 Å/ps) influence the tribological response of SiC. The results indicate that increasing temperature generally reduces both friction and normal forces, consistent with thermal softening and enhanced atomic mobility, while the friction coefficient shows only a weak and slightly non-monotonic dependence across the studied range. Penetration depth plays a dominant role: deeper indentation markedly increases tangential resistance and the friction coefficient, which is associated with an expanded plastic deformation zone and a thicker third-body debris layer. By contrast, under a fixed penetration depth of 10 Å, the average friction coefficient is largely insensitive to sliding velocity within 0.2–0.8 Å/ps, although higher velocity intensifies force fluctuations. These findings provide atomic-scale insights into the governing mechanisms of SiC friction and wear and offer guidance for performance optimisation under extreme operating conditions.