Molecular Dynamics Simulations on the Effects of Abrasive Spacing and Water Environment on Surface Damage in SiC Nano Polishing

Silicon carbide (SiC) is widely used in power electronics, aerospace, and high-temperature applications due to its excellent thermal conductivity, mechanical strength, and radiation resistance. However, its high hardness and brittleness make achieving damage-free ultra-precision surfaces particularly challenging. Nano polishing is essential for achieving high-quality SiC surfaces. To improve surface quality in the ultra-precision machining of SiC, this study employs molecular dynamics (MD) simulations to investigate the synergistic effects of abrasive spacing and water environment during nano polishing. By adjusting abrasive radius and center-to-center distance, the abrasive density is controlled, With the increase of abrasive spacing, the abrasive particles gradually change from collective action to individual action. The results reveal that dense abrasive spacing facilitates efficient atomic removal, whereas sparse spacing tends to induce atomic stacking and microcrack formation. Water lubrication effectively reduces normal polishing forces and local substrate temperature, dissipates part of the heat generated during the polishing process and inhibits changes in the crystal structure of the surface, thereby reducing the formation of defects and dislocations. This study uncovers the material response under multi-factor coupling in nano polishing and provides theoretical guidance for optimizing SiC polishing parameters.