Product Code: ICAL05_2206

High-Frequency Beam Oscillating to Increase the Process Stability During Laser Welding with High Melt Pool Dynamics
Authors:
Heinz Haferkamp, Laser Zentrum Hannover e.V.; Hannover Germany
Olaf Berend, Laser Zentrum Hannover e.V.; Hannover Germany
Oliver Meier, Laser Zentrum Hannover e.V.; Hannover Germany
Lars Engelbrecht, Laser Zentrum Hannover e.V.; Hannover Germany
Presented at ICALEO 2005

Nd:YAG lasers with a double focus technique are usually used for welding of aluminium alloys, due to a low melt pool viscosity. For double focus welding, relatively high laser output powers and energy per section are necessary. Thus, techniques for reducing laser powers and energy per section for process-safe welding are in demand. Also, when laser welding zinc-coated steel sheets with overlap seams, improper degassing and weld pool sputtering can occur.
This can be avoided by increasing keyhole geometry in welding direction using high-frequency oscillating of the beam. In this research project, this technology should be transferred to laser welding, using adapted optics.
Laser welding of aluminium alloys with a high-frequency oscillation beam should allow high process stability and lower energy per section welding, using much lower output powers, increasing the application spectrum of existing applications.
In this project, a processing head is being developed, which will be advantageous for laser welding of zinc-coated steel and aluminium alloys. By increasing the humping limit higher welding speeds are possible. By oscillating perpendicular to the feed direction, higher gap bridging is also possible. Further advantages can be expected for degassing of overlap welds for zinc-coated sheets.