Product Code: PIC2008_303

Welding Performance of a 2KW Continuous Wave Supermodulated Nd:YAG Laser - Increased Weld Speed, Weld Penetration and Reduced Porosity with Supermodulated Output Power
Authors:
Mohammed Naeem, GSI Group, Inc. - Laser Division; Rugby Great Britain
Richard Jessett, Gsi Group; Rugby Great Britain
John Chinn, Gsi Group; Rugby Peoples Republic of China
Presented at PICALO 2008

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 lasers output- a more efficient beam-material interaction.

At GSI Group, we have undertaken a number of initiations to raise Nd: YAG laser power and its processing performances. Work has centred on high average power (500W-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. Weld penetration improvements of up to 30-40%, depth of focus improvements of 40%, and the ability to weld more reflective alloys at low average power are just some of the gains made by employing SuperModulateTM in welding.

This paper documents the basics of generating SuperModulated beams but emphasizes the process improvements in welding of standard alloys.