Suppression of melt flow instabilities by amplifying high-frequency melt waves in laser fusion cutting

High-frequency resonant melt waves locally increase the stability of melt flow and enhance cut flank quality. To amplify these waves along the melt flow, an acoustically tuned cutting nozzle, termed the cutting whistle, generates gas flow oscillations based on a resonant cavity. The nozzle cavity is designed for 6 mm thick sheets, causing the gas flow to oscillate at 15 kHz within the kerf, creating a uniform melt flow with synchronized oscillating melt waves. Performance evaluations on stainless steel sheets show that, compared to a standard conical nozzle, the cutting whistle reduces surface roughness across the entire cutting depth and prevents coarse structures near the upper sheet surface and at the bottom in burr-free cuts.