A multiphase flow model simulation of water jet-guided laser drilling in 304 stainless steel

Water jet-guided laser (WJGL) machining is extensively employed for high-precision and low-damage ablation. However, the erosion mechanism of WJGL processing is still being continuously explored. This study proposes a theoretical model to describe the interaction between WJGL and 304 stainless steel. A three-dimensional (3D) transient model is developed to simulate the WJGL drilling process on 304 stainless steel. The model achieves the first combined effect of the laser and water jet on the substrate. It accounts for the melting and vaporization processes of the material, employing a multiphase flow model to simulate heat transfer, phase transition, and fluid flow during the drilling process. Using this model, this paper numerically investigates the effects of laser power, pulse frequency, water pressure, the number of pulses on the WJGL drilling process, and the evolution of hole morphology. Experimental and simulation results concerning hole size and morphology are compared to validate the model. Based on the simulation results, the formation mechanism and evolution of the recast layer on the 304 stainless steel surface are explored. These findings contribute to a deeper understanding of WJGL drilling and offer theoretical references for improving processing quality.