October 12--In a one-time experimental setup, TRUMPF laser specialists were able to weld copper sheet metal 5mm deep with a combination of disk lasers of varying laser power. Reportedly, no one had ever been able to do this before. As a highly reflective material, copper is extremely difficult to weld. In most cases, undesirable side effects occur, including blowholes in the weld seam.
The specialists at TRUMPF connected together three disk lasers with 4kW, 6kW, and 8kW laser output using a special fiber coupler in the application lab. Over 16.5kW were brought onto the workpiece. The resulting welding speed of 1.8 m/min stabilized the extremely dynamic melt pool common to copper. The sheets, each measuring 3mm in thickness, were welded together 5mm deep as an overlap joint with excellent seam quality. For this experiment to be both secure and successful, the disk lasers had to be finely synchronized, an accomplishment ensured by the TRUMPF Laser Network (TLN).
Whether this welding application is ready for mass production depends greatly on the welding speed and the chosen focus geometry. More powerful lasers, such as those offered by TRUMPF beginning in December 2006, permit even greater welding speeds and an expanded process window with consistent seam quality.