Multi-sheet structures in 7475 aluminum by friction stir welding in concert with post-weld superplastic forming

Diffusion bonding/superplastic forming (DB/SPF) is an established fabrication technology for titanium aerospace components. However, DB cannot be applied easily to aluminum alloys because of tenacious surface oxides. Friction stir welding may eliminate this problem and allow fabrication of multi-sheet structures via friction stir welding/SPF. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.