High brightness lasers in cutting applications

Laser cutting machines with linear motor drives provide high contour accuracy and high cutting rates. Thus laser beam cutting has become increasingly competitive compared to mechanical precision cutting [1]. Since the several years, new laser beam sources are available for cutting. One of the promising solutions is cutting with fiber lasers. The fiber laser has several advantages such as absorption rate, power efficiency, fiber delivery, better focusing if compared to the CO2 laser. During the recent years, the system technology for laser beam cutting was upgraded at Fraunhofer IWS Dresden [2]. In particular, a precision 3D-laser cutting system with linear drives, robotic systems and several fiber lasers have been installed. Within the frame of several research projects laser beam cutting with CO2-and fiber lasers has been investigated in order to compare the cutting quality and cutting performance of two beam sources. Objective of these studies was to find out if the cutting quality is sufficient and if the requested cutting rate can be obtained. It could be learned that the cutting quality for both lasers is good. The edge quality is sufficient for most of the materials and thicknesses. However, using single and multimode fiber lasers in the kilowatt range can increase the cutting speed and can thus reduce the cutting time [3][4]. This paper describes the gained user experience of Fraunhofer IWS. Various beam sources are compared and evaluated with respect to specific applications. Moreover, the advantages and disadvantages for material processing applications will be explained.