Thermal analysis of in-situ laser assisted diamond cutting of fused silica and process optimization

Fused silica is typically a difficult material to machine using conventional methods due to its high brittleness and hardness, despite its significance in optical systems such as high-power lasers and astronomical telescopes. Laser assisted diamond cutting has emerged as a promising and cost-effective alternative for machining fused silica. This study investigated the machinability and thermal response of fused silica during in-situ laser assisted diamond cutting through finite element analysis and cutting experiments. The temperature dependence of thermal parameters, identified by Beetle Antennae Search, was taken into consideration in the thermal model. To minimize surface roughness and determine the optimal machining parameters, various methods were employed, including analysis of variance, signal-to-noise ratio, and Particle Swarm Optimization coupled with Artificial Neural Network. The results indicated that various factors involved in in-situ laser assisted diamond cutting had a significant impact on the thermal response of fused silica, resulting in different surface roughness. Among these factors, spindle speed, feed speed, cutting depth, and laser power contributed to surface roughness by 17.34 %, 12.28 %, 12.03 %, and 48.31 %, respectively. By utilizing the optimal combination of parameters, which comprised a spindle speed of 2700 rpm, feed speed of 1.7 mm/min, cutting depth of 2.7 mu m, and laser power of 12.5 W, a smooth surface finish of Sa 12.9 nm could be obtained.