Innovation in high speed laser scanning and intelligent sensor systems for material processing

摘要

High-speed laser scanning systems have been known from laser marking applications for several years. The beam deflection is done by small galvo-driven scanning mirrors, which were capable of transmitting several hundred watts of laser power. Innovative developments have resulted in scanning systems capable of transmitting several thousand watts of CO{sub}2 and Nd:YAG laser power. In conjunction with new processing optics and intelligent sensor systems, this technology opens up new perspectives in high precision, high-speed laser welding of complex shaped and small parts. The paper will introduce a welding application in which an integrated optical sensor provides exact positioning of the laser beam prior to welding. The tilting motion of the mirrors guides the laser beam rapidly and precisely on a well-defined path on the part contour with both the welding head and the part fixed. Another example will describe a hardening application. Here the scanning head is utilized to optimize the shape, size and intensity distribution of the laser spot on a tool surface. A pyrometer based process control is used to monitor the surface temperature and change the process parameters accordingly.