Evolution of Mechanical Properties of Single-Crystal Silicon Carbide under Atomic Oxygen Erosion

Reactive molecular dynamics (RMD) method is employed to investigate the evolution of transverse and surface mechanical properties of single-crystal silicon carbide (SiC) materials under atomic oxygen (AO) oxidation erosion. Transverse tensile simulations reveal that AO erosion degrades the crystal structure, altering the crack propagation mechanism. Transverse compression simulations indicate that AO erosion weakens compressive properties, modifying the stress pattern and degrading mechanical properties following amorphization. Nanoindentation analysis shows that AO erosion diminishes the anisotropic characteristics of the single-crystal surface structure. Simultaneously, the amorphization process enhances the surface’s recovery capacity. Comparative analysis illustrates that the rapid formation of an amorphous oxide layer on the Si-surface material effectively protects its internal crystal structure, resulting in better uniaxial tensile, compressive, and surface mechanical properties compared to the C-surface material after AO erosion.