A comparison of gas tungsten arc and CO2 laser beam welding of AA2024

Mechanical fastening methods are used extensively to join aluminum alloys, particularly in the aerospace industries. Laser welding provides the possib ility of a high productivity single-step process, with the added benefit of potential weight savings of about 10% in comparison with riveting. However , the weldability of many aluminum aerospace alloys is generally considered to be low, and little data are currently available. A procedure for CO2 la ser welding of the alloy AA2024 is developed, with the use of 2319 filler w ire. Weld property data are shown to achieve the requirements for the most stringent quality level of the current European workmanship standard for la ser-welded joints in aluminum. Hardness and tensile strength properties are shown to be similar to those of gas tungsten are (GTA) welds. The fatigue strength of GTA welds is superior to that of laser welds in the as-welded c ondition, but when the weld bead is machined flush with the plate surface t he difference is reduced. The laser welds achieved the requirements of reco mmendations produced by the International Institute of Welding for single-s ided welding of aluminum alloys. The quality of the weld toe is shown to ha ve the greatest effect on fatigue strength. (C) 2001 Laser Institute of Ame rica.