A novel sequential micromanufacturing strategy for efficient grinding of 2.5D SiC_f/SiC ceramic matrix composites

As a key material for hot-section components in aero-engines, SiC_f/SiC ceramic matrix composites are difficult to machine due to their high hardness and brittleness, significantly limiting their engineering application. Although laser ablation machining can effectively improve the machinability of SiC_f/SiC, conventional single-wavelength lasers struggle to simultaneously achieve sufficient modification depth and a controlled heat-affected zone (HAZ). Moreover, the synergistic mechanisms and sequential control of multi-laser processing lack systematic investigation. This bottleneck hinders the further application of laser ablation technology in composites. Therefore, there is an urgent need to explore the synergistic mechanisms of multi-wavelength lasers and develop novel processing techniques. This study proposes a novel sequential micromanufacturing strategy based on combining laser techniques ‘circular oscillation infrared (COIR) laser pretreatment and defocused ultraviolet (DLUV) laser layer-by-layer oxidation’. The synergistic interaction of COIR laser and DLUV laser enables fabrication of a uniform, loosely structured oxide-modified layer with a greater modified depth than an ordinary combination of two lasers besides substantially reducing the subsurface HAZ. Experimental results demonstrated that this hybrid laser-assisted grinding process significantly reduces the grinding force by approximately 33% compared to single laser-assisted, suggesting a new pathway to green manufacturing. In conclusion, the work reports new pathways to energy-efficient and improved machining quality of ceramic matrix composites, hitherto unreported.