Product Code: ICAL05_507

The Effect of Laser Beam Quality When Welding with High-Power CW Solid-State Lasers
Authors:
Geert Verhaeghe, The Welding Institute; Cambridge Cambs UK
Paul Hilton, The Welding Institute; Cambridge Cambs UK
Presented at ICALEO 2005

Only 10 years ago, the only commercially available high-power, fibre-delivered laser was the lamp-pumped Nd:YAG rod laser. Today however, diode-pumped Nd:YAG rod lasers, thin-disc Yb:YAG and Yb-fibre lasers are also available for material processing. This means that today's laser user needs to consider parameters such as beam quality and power density (and possibly others), in addition to the actual technology used in generating the laser beam, when selecting a laser for their welding application(s). To provide information in this area, a study was carried out investigating the welding performance of a range of CW fibre-delivered laser sources and beam focusing systems, with beam parameter products between 23 and 4mm.mrad and spot sizes from 0.61 to 0.14mm. A controlled series of experiments was carried out on aluminium and steel to determine depth of penetration as a function of welding speed for a constant laser power of 4kW. This paper describes the results of this study, as well as recommendations for choosing an appropriate laser source and beam focusing system to maximise welding performance.