Surface modification mechanism of silicon nitride by LAG

Silicon nitride (Si₃N₄) is widely used in multiple fields due to excellent properties. However, the improvement of the mechanical properties by the existing processing is limited, and the surface modification mechanism of the material is not enough. Therefore, laser-assisted grinding (LAG), combing laser heating with grinding, is proposed. The LAG process is simulated by molecular dynamics (MD) simulation, and the Si₃N₄ grinding force, atom removal, damage mechanism, and residual stress are investigated. The machining surface hardness arrives at 1862.6 HV, higher than traditional grinding (TG). The grinding force and surface roughness are reduced by 53% and 25.6%, respectively. The study results promote high-performance fabrication of substrate surfaces while filling up the study of Si₃N₄ matrix removal and damage.