Investigation on system design methodology and cutting force optimization in laser-assisted diamond machining of single-crystal silicon

Laser -assisted diamond machining provides a cost-effective approach for cutting hard and brittle materials. To expand its practical application, a comprehensive understanding of the design methodology of the laser -assisted diamond machining system and optimization of process parameters for machining single crystal silicon is crucial. This study presents, for the first time, an optical design methodology, with a particular emphasis on the design method for diamond cutting tools. The adequacy of the proposed method is verified through optical simulation. The numerical analysis indicates that the incident surface of the diamond cutting tool should be positioned within the Rayleigh range of the laser beam, and the optimal laser incident height is determined to be 0.7 mm. Furthermore, high -temperature nanoindentation tests reveal a significant reduction in the hardness of single crystal silicon by 72.04 % and a reduction in Young's modulus by 30.70 % at a temperature of 600 degree celsius due to increased dislocation activity. Orthogonal experiments based on the Taguchi method reveal that the feed speed has the most significant impact on the resultant force during laser -assisted diamond machining of single crystal silicon. The contribution rates of spindle speed, feed speed, cutting depth, and laser power to the resultant force are determined to be 31.47 %, 35.82 %, 22.02 %, and 8.04 % respectively. A regression model is established through multiple nonlinear regression analysis to quantify the correlation between the input parameters and the resultant force. The optimal parametric combination is determined using nonlinear programming optimization, resulting in a spindle speed of 3061.45 rpm, a feed speed of 4 mm/min, a cutting depth of 4 mu m, and a laser power of 1.5 W. Validation experiments demonstrate that the established mathematical regression model accurately forecasts the resultant force.