Controlling the laser-induced textures for high-quality micro-grinding of monocrystalline silicon

The high-quality and low-damage processing of hard, brittle and difficult-to-cut materials is a well-recognized technical challenge. Herein, a hybrid machining method, laser-induced texturing assisted micro-grinding (LIT-MG), is introduced to process monocrystalline silicon (Mono-Si). The influences of laser parameters on ablation behavior, surface morphology, and grinding quality of Mono-Si are revealed through finite element simulation (FEM) and comparative experiments. A thermal–mechanical coupling model for nanosecond laser ablation is established to analyze the evolution characteristics of temperature, stress, and ablation depth. The surface forming differences between LIT in air (LIT-A) and NaOH liquid solution (LIT-L) are compared. It was found that the laser power and scanning speed greatly affect texture morphology and thermal damage distribution. The NaOH solutions could effectively promote the oxidation modification of the substrate, thereby softening it and facilitating subsequent MG process. The surface roughness of LIT-L-MG ( R a 0.16 ± 0.03 μm) is reduced by 50.00% and 56.76% compared with MG ( R a 0.32 ± 0.02 μm) and LIT-A-MG ( R a 0.37 ± 0.05 μm), respectively. The machined surface of LIT-L-MG shows no obvious edge chipping, debris or brittle spalling. Transverse and longitudinal microcracks are controlled within the modified layer, and no penetrating cracks propagate into the substrate. The LIT can also reduce the amount of material removed by MG. By prefabricating controllable microstructures and surface modification, LIT could greatly improve the grinding removal behavior of Mono-Si, thus providing a feasible approach for high-quality and low-damage machining of hard and brittle materials.