Abstract
We constructed a system incorporating integration optics and a newly developed pulse excited YAG laseroscillator of 1.5 kW average power. Two CW YAG laser oscillators of 2 kW average power, and a PC were alsoincorporated. The integration optics combined three laser beams transmitted through optical fibers. Using thissystem, we are able to obtain the following results. (1) Good welding quality was achieved with a focused spotdiameter with integration optics. Furthermore, quality was attained without changing the work distance byadjusting the collimator lenses of the integration optics. (2) The delay time between the pulse excited YAGlaser beam and the rectangularly modulated CW YAG laser beams greatly influenced the cross-sectional shapesof weld. The full penetration weld of a 10 mm thick SUS304 plate is obtained by half power density of thesimultaneous irradiation of the pulse excited and two rectangularly modulated CW YAG laser beams, when theformer beam is irradiated just after a keyhole has been formed by the latter laser beams. (3) The deepestpenetration depth and the largest volume of weld is obtained from the overhead position welding, as comparedto the flat, horizontal, and vertical position welding.
