Experimental investigation on high-efficiency milling of silicon carbide ceramics by high-energy rotary coupled nanosecond laser

Reaction-bonded silicon carbide (SiC) ceramics are widely employed in advanced industrial applications due to their exceptional mechanical and physicochemical properties. However, conventional nanosecond laser processing of SiC ceramics often suffers from non-uniform energy distribution, unstable ablation behavior, and severe thermal accumulation under high-energy conditions, making it difficult to simultaneously achieve high material removal efficiency and acceptable surface quality. In this work, high-speed milling of SiC ceramics was carried out using an innovative high-energy rotary coupled nanosecond laser processing method to address this challenge. The evolution of laser energy density before and after coupling was simulated to clarify the beam homogenization mechanism. The effects of single-pulse energy (E p ) and X-direction overlap rate ( X ov ) on the surface morphology and processing efficiency were systematically investigated. The results show that rotary coupling effectively homogenizes the laser energy distribution, leading to stable material removal and uniform surface formation. The material removal rate ( MRR ) increases nonlinearly with E p , reaching up to 13.14 mm 3 /min, while the optimal surface quality improvement rate reaches 25.17%. Scanning electron microscopy revealed a uniform and dense nanoparticle re-solidified layer that suppresses micro-pits, cracks, and slag accumulation. Energy-dispersive spectroscopy and Raman analyses confirmed carbon volatilization, oxygen enrichment forming an amorphous Si-O layer, and reduced residual stress through optimized Si-C bonding. Overall, this study demonstrates the feasibility of achieving efficient material removal and surface reconstruction of SiC ceramics via photothermal-chemical interactions, providing a promising and controllable strategy for extreme laser processing of brittle and hard materials.