Beam Oscillation of Keyhole Mode Hot Wire Laser Welding of Thin Sheet Aluminum Alloys

Joining thin sheet metals often leads to melt-through and distortion—issues that are of particular concern with aluminum alloys. Gas metal arc welding (GMAW) and gas tungsten arc welding (GTAW) processes have low heat input waveforms yet still have thermal input challenges with thin gauge metals. Hot wire laser welding (HWLW) is a novel joining method that has been developed to achieve acceptable fusion for thin sheet metals, while minimizing heat input and distortion. This is achieved with an arc-suppressing waveform so that resistive heating and laser power are the only sources of heat input. This work explores the use of beam oscillation and keyhole mode for HWLW, which resulted in deeper penetration, faster travel speeds, and lower laser power, as opposed to HWLW with conduction mode.