Application of Solid State Welding and Superplastic Forming to Aerospace Vehicles

In this paper, manufacturing of launcher structural components with superplastic forming (SPF) and solid state welding technologies is presented with several examples. Some of high strength aerospace alloys, like aluminum, titanium and superalloys, are known to have superplasticity so that complex shapes of aerospace components can be produced with this technology. A combination of superplastic forming and solid state welding processes produces lighter and stiffer components than one manufactured with conventional machining and welding. Solid state welding is an attractive method to weld materials without melting where mechanical properties are important since the welding interface is homogeneous without liquid phases. The results includes aluminum and titanium tanks cryogenic application, a scaled combustion chamber with duplex stainless steel and copper alloy, and lightweight aluminum-copper-lithium cylinder manufactured by superplastic forming and diffusion bonding or friction stir welding.