Plates of Al2219 and Al6061 were butt welded autogenously using a CO2 laser. Preliminary bead-on-plate welding experiments were carried out in order to determine the optimum laser conditions for the individual alloys. It was observed that, for the same average delivered power, the weld widths and depths of penetration were an order of magnitude higher with pulsed laser welding compared to continuous wave laser welding for both alloys. Hence pulsed laser welding was the primary technique selected to butt weld Al2219 to Al6061. The average laser power in this case was controlled by varying the pulse duty cycle.
The effect of varying assist gases was also studied. Argon, helium, nitrogen and compressed air were used as assist gases. The welded samples were analyzed and the weld microstructure characterized. It was observed that the assist gases dictated the presence or absence of porosity and cracking in the weld. They, however, were found to have no significant effect on the depth of penetration.