Quality and performance of laser cutting with a high power SM fiber laser

The introduction of high power single mode fiber lasers allows for a beam of high power and a good beam quality factor (M2 ” 1.2), compared to the multimode fiber lasers often utilised in macro laser metal cutting. This paper describes fundamental studies of macro laser metal cutting with a single mode fiber laser to study the performance of such lasers in terms of cut quality and process performance. Linear cut experiments have been performed applying a 3kW single mode fiber laser and varying the following parameters: laser power, cutting speed, focal length, focus position, cutting gas pressure and plate thickness. Parameter studies have been performed in mild steel, stainless steel and aluminium. The cut qualities investigated are: cut width on surface and backside of workpiece, parallelism of top kerf and burr length. The results are a guideline on how the investigated parameters influence the cut quality and the maximum cutting speed in the investigated parameter space. Furthermore the
achieved cutting performance is benchmarked to laser cutting with other types of lasers, CO2-lasers, disc-lasers as well as multimode fiber lasers.