Product Code: ICA12_1702

High-Quality Laser Welding of Copper Using Appropriate Power Modulation - Invited Presentation - 40 Minutes
Authors:
Andreas Heider, Institut fuer Strahlwerkzeuge (IFSW); Stuttgart Germany
Rudolf Weber, Institut fuer Strahlwerkzeuge (IFSW); Stuttgart Germany
Thomas Graf, Institut fuer Strahlwerkzeuge (IFSW); Stuttgart Germany
Presented at ICALEO 2012

Due to its very good electric and thermal conductivity, copper is an important material with a wide range of applications, which require an efficient and reliable welding process, preferably with laser beams. The same material properties make laser welding of copper a challenging task. To achieve welds with penetration depths of several millimeters in copper using commercially available laser sources relatively low feed rates below 10 m/min are needed. Welds in copper at such low feed rates with 1 microns wavelength lasers often suffer from numerous weld seam defects such as melt ejections and pores.
In this paper the influence of power modulation during copper welding on weld defects is discussed. Presuming the correct parameters modulation of the power shows very distinct advantages. On the one hand a strong reduction in number of melt ejections was measured. On the other hand a significantly more regular and homogeneous solidified weld seam surface for the modulated welds was achieved. In addition the penetration depth could be increased. Results will be presented for different copper alloys. Furthermore the influence of the modulation frequency and amplitude will be discussed.