Fast Laser Cutting of Thin Metal

Since the emergence of high power single mode fiber lasers cutting velocities of more than 100 m/min can be achieved easily on a straight cut. Results of laser fusion cutting of thin sheet metal with a 2 kW single mode fiber and 4 kW laser will be introduced. Several thicknesses of electrical sheets, aluminium sheets and high strength steel sheets have been cut with maximum speeds of 150 m/min. The cutting quality in terms of cutting edge appearance, burr formation, and kerf width has been analysed. In the case of 2D contour cutting high cutting speeds cannot be accomplished due to steady decelerating and accelerating of the cutting machine. Two alternative concepts will be presented which help to realize high cutting speeds on a contour cut: The first concept shifts the machine movement for filigree structures to high dynamic light weight linear axes whereas the second concept forbears to use cutting gases and allows therefore the usage of galvanometer driven fast mirrors to move the laser beam.