High speed laser cutting of thin metal sheets

Increasing productivity in splitting up of metal sheets by means of mechanical cutting processes is today limited by long change-over times as well as nonproductive times and insufficient quality caused by tool wear. In the case of highquality materials even a slight quality reduction concerning development of dross attachment and induced stress leads to a lot of rejects.In order to increase the cutting speeds within a range economical for industrial use, i.e. about 100 m/min, a completely new type of laser cutting processhad to be developed. As opposed to conventional laser cutting, during which a semicylindric cutting front is formed, a closed keyhole with subsequent melt film ejection is produced during the completely new laser cutting process.The incoupling of energy no longer only results from pure surface absorption but in addition from plasma formation and multiple reflection.