Sound Welding of Copper: Laser Beam Welding in Vacuum

Abstract

Copper is one of the most important metals of modern times. The extensive usage from thin foils up to thick plates leads to a huge amount of welding applications. Basically the Laser Beam Welding is suited well for the welding of copper, because difficulties such as the high thermal conductivity can be overcome by high intensities. However in industrial applications, a sufficient process capability is currently only achieved at high welding speeds. This leads to low penetration depths and high demands in terms of laser power. At low welding speeds weld metal ejections, which cause critical defects occur.By Laser Beam Welding in Vacuum (LaVa) the process capability can be increased significantly. Weld metal ejections at low welding speeds can be prevented. By applying this process variation, high quality welding of copper at a low power level between 4 kW and 8 kW and a low intensity level between 50 kW/mm2 and 80 kW/mm2 of a multimode solid state laser becomes possible for penetration depths of 3 to 8 mm.