Copper sheet securely welded by disk lasers

27 Oct 2006

Trumpf has met the challenge of welding shiny copper sheet by using multi-kilowatt disk lasers. The company has also reported positive financial results for 2005-6.

There seem to be no limits on the disk laser's capabilities. What experts had previously held to be an extremely difficult task, Trumpf says it has achieved in a recent one-time experimental demonstration. Its laser specialists have welded copper sheet metal 5 mm thick using a combination of disk lasers of varying laser power.

No one had been able to do this before: as a highly reflecting material, copper is extremely difficult to laser weld. In most cases, undesirable side effects occur, including blowholes in the weld seams.

The engineers at Trumpf connected together three disk lasers with 4, 6 and 8 kW outputs using a dedicated fiber coupler in the application lab. In total, more than 16.5 kW were focused onto the work-piece. The resulting welding speed of 1.8 m/min stabilized the extremely dynamic melt pool typical of copper metal.

The copper sheets, each measuring 3 mm in thickness, were welded together 5 mm deep as an overlap join with an "excellent" seam quality, Trumpf reported. For this experimental demonstration to be both secure and successful, the disk lasers had to be finely synchronized, which was effected with Trumpf's Laser Network (TLN).

Whether this welding application is ready for mass production will depend greatly on the welding speed and the chosen focus geometry, Trumpf stated. More powerful lasers, such as those offered by the company from December 2006, will permit higher welding speeds and an expanded process window with consistent seam quality.

Trumpf reports 'record' sales figures for 2005-6

Trumpf, which develops both laser-based and other types of machine tools, this week reported that it ended the 2005/06 fiscal year with record sales of €1.65 billion.

With an 18% growth rate, the company said it has demonstrated success under its new management: pre-tax income increased considerably by 53% to €205 million, while profit margin grew to 12.4%.

Nicola Leibinger-Kammüller, president of Trumpf's managing board said at the company's annual press conference that the current fiscal year is also going well. "Trumpf is expecting sales to reach more than €1.8 billion.

"One reason for our positive outlook is our orders on hand totaling €470 million. The first three months of the new fiscal year [2006-7] have supported this expectation: Sales and orders received both rose by just under 25%."

The engines for Trumpf's success have been machine tools for sheet metal processing. Growth in the machine and power tools division increased its sales by 23% to €1.44 billion. The laser technology/electronics division enjoyed an 8.5% sales increase to €438 million. The Electronics business field recorded strong gains.

Overall, Trumpf invested €120 million in R&D research and development: a 12% increase on last year's figure.