WELDING PERFORMANCE OF A 2KW CONTINUOUS WAVE SUPERMODULATED ND: YAG LASER- INCREASED WELD SPEED, WELD PENETRATION AND REDUCED POROSITY WITH SUPERMODULATED OUTPUT POWER

摘要

The development of disk and fiber laser with a high beam quality in the multikilowatt range has led to new industrial processes and enhancement of the standard processes in terms of processing speeds, welding depth etc. However a laser with high average power and high beam quality is not always the answer because: o Laser with a high average power and beam quality is more expensive o With high average power the processing speeds can be increased but there is no gain in efficiency meaning that costs and/or distortion can be greatly increased. o A better solution would be to get more from the laser's output-a more efficient beammaterial interaction. At GSI Group, we have undertaken a number of initiatives to raise Nd: YAG laser power and its processing performances. Work has centred on high average power (400W-2000W) continuous wave (CW) systems. Continuous wave (CW) Nd: YAG lasers with beam quality of 25mm-mrad or better that can also SuperModulateTM to peak powers of up to 2 times of their average power ratings have been shown to improve material processing. This paper documents the basics of generating SuperModulated beams but emphasizes the process improvements in welding of standard alloys.