Optimization Study of Laser-Drilling Processes in Stainless Steel Under Two Scanning Path Strategies

To optimize the quality of picosecond laser drilling in stainless steel, this study systematically investigates the key influencing factors and optimization strategies of the laser-drilling process through experimental methods. In the experimental section, a single-factor comparison experiment was conducted to evaluate two picosecond laser-drilling paths. The results show that the holes produced using the equidistant concentric circle path exhibited superior overall quality. Based on this finding, further orthogonal experiments were carried out using the equidistant concentric circle path to optimize the process parameters. The orthogonal experimental results indicate that the number of scans has the most significant effect on the inlet hole diameter and roundness; the pulse energy greatly influences the outlet hole diameter, outlet roundness, and hole taper; and the scanning speed has the second-most significant effect on all hole parameters. By applying a comprehensive balancing method to the orthogonal experimental results, the optimal process parameters were determined: pulse energy at 90% (total power 30 W), 35 scans, and a scanning speed of 20 mm/s. This combination effectively reduced the hole taper, increased the roundness, and minimized the hole diameter, significantly improving the overall hole quality.