N. Kapustka, Edison Welding Institute, Columbus, OH; I. D. Harris, J. Bernath, EWI, Columbus, OH
The main drivers for development/implementation of advanced welding in aerospace applications are high material cost, long lead times on materials and components, and increasing performance requirements. Increasing performance requirements have resulted in the use of some difficult-to-weld nickel-based superalloys in gas turbine engine components. These materials can be susceptible to heat affected zone and fusion zone cracking during welding for maintenance, repair, and overhaul. Cracks adjacent to rivet holes are currently repaired by reaming the hole and either replacing the rivet, gas tungsten arc plug welding or friction stir plug welding. Rivet replacement is labor intensive and does not ensure elimination of cracks. Gas tungsten arc plug welding can result in relatively high distortion while application of friction plug welding is limited by fixture accessibility – these techniques are used for repairing miss-located holes in airframe structures as well. Other than repair techniques for nickel-based superalloys, fabrication and repair methods for Ti-6-4 structural components are also needed.
This paper addresses the above challenges and provides examples of advanced welding processes that have been implemented in fabrication and repair of aerospace components. Laser powder build-ups with Rene 142, resistance hole repair techniques, repair of structural components with reciprocating wire feed gas metal arc welding, and fabrication of airframe skins and structural components with hybrid laser welding and friction stir welding are discussed.
Summary: The implementation of several welding processes for the manufacture and repair of aerospace components is presented. The processes discussed include Laser Addivite Manufacturing, Resistance Welding Hole Repair, Reciprocating Wire Feed Gas Metal Arc Welding, and Friction Stir Welding. These processes have been applied by Edison Welding Institute for the manufacture and repair of turbine engine and airframe components produced from materials which include nickel-based superalloys, titanium, magnesium, and aluminum.
