Numerical and experimental analysis of nanosecond laser ablation of SiC

This work presents a fundamental study on the melting threshold, ablation morphology and removal mechanism of single-crystal SiC during nanosecond laser processing. A thermal model was established to investigate the thermal behavior of single-crystal SiC at different wavelengths and pulse durations, and to predict the size and cross-sectional profile of ablation hole. The phase transitions and thermophysical parameters variation of silicon carbide with temperature were considered in the numerical analysis. To verify the reliability of the established model, the simulation data were compared with experimentally measured ablation depth under the same operating parameters. The investigation results indicated that the melting threshold of crystalline material increased with the increase of wavelength under the studied condition and was approximately linear distribution. Surface evaporation should be the dominant removal mechanism for nanosecond laser pulse ablation of SiC. By comparing the diameter and depth of ablated hole obtained from experiment and simulation calculation, it is found that the experimental/modeling coupling method had good consistency. Therefore, the established model can accurately simulate the interaction process between nanosecond laser pulse and silicon carbide.