Quantitative study of melt flow dynamics inside laser cutting kerfs by in-situ high-speed video-diagnostics

Within this paper the melt flow dynamics of the laser cutting process during laser cutting of 6 mm thick stainless-steel using a disk laser with a laser power of 5 kW and nitrogen assist gas with a pressure up to 20 bar, is analyzed by in-situ high-speed video-diagnostics (>100,000 fps). An advanced algorithm is used to determine spatially resolved the melt flow dynamics on the laser cutting front. The results reveal a link between the fluid dynamics, the cutting velocity, the assist gas pressure and the average roughness of the cut flank.