Laser Hotwire Welding of Aerospace Alloys

Laser hotwire welding is a unique variant of laser welding which feeds a resistively heated consumable weld wire into a laser weld pool. The preheating of the wire reduces the laser power required to melt the wire and form a weld. The reduction in required laser power results in numerous benefits including a lower heat input, a higher deposit rate, and improved wetting. The lower heat input reduces both distortion and degradation of base metal properties which is of high importance for materials used in aerospace applications. Higher deposition rates can improve the economics of the manufacturing process, and improved wetting can reduce potential defect formation. The current work investigated the use of laser hotwire welding with aluminum alloys. Initial results indicated that laser hotwire welding has significantly reduced distortion when compared to traditional arc welding processes. This investigation included the characterization of the process-structure-properties relationship of laser hotwire welding of aluminum alloys, as well as a preliminary investigation of in-process monitoring using the in-line coherent imaging.