Laser weld bond (LWB) is a hybrid assembly process which combines laser welding and adhesive bonding to generate higher joint shear and peel strengths over conventional welding or adhesive bonding alone. This process has the ability to demonstrate significant manufacturing process simplification to produce very cost effective airframe structures and control surfaces. Though this process can be accomplished with a variety of lasers, adhesives and substrates, this research focuses on laser weld bonding of 1.0 to 1.6-mm thick 6013-T6 aluminum alloy using a 5 kW fiber laser with Al 4047 filler wire and Hysol EA 9628 epoxy film adhesive. The intent of this applied research was two-fold; select an FAA approved "placement-friendly" adhesive and primer combination and validate the feasibility and performance of the laser weld bond process through experimentation.

Using a Box and Behnken experimental design, several laser weld bond variables including laser power, working distance, weld speed, wire feed rate and gas flow rate were investigated to measure their effect on joint shear and peel strengths. Analyses of the experiment results produced predictive LWB shear and peel models and identified laser weld bond variables that maximized weld joint strengths. The analyses conducted indicated that the models had a high degree of predictive capability and were sufficient to represent the relationship between the LWB shear and peel responses and the significant variables. Further mechanical testing of LWB joints validated the predictive models, and demonstrated that the LWB process is a viable joining alternative capable of producing joint strengths which exceed target rivet joint strength requirements.