Creep-age forming of AA7475 aluminum panels for aircraft lower wing skin application

Creep-age forming (CAF) is an interesting process for the airframe industry, as it is able to form or shape panels into smooth, but complex, curvatures. In the CAF process, the ageing cycle of the alloy is used to relax external loads imposed to the part, through creep mechanisms. Those relaxed stresses impose a new curvature to the part. At the end of the process, significant spring back (sometimes about 70%) is observed and the success in achieving the desired form depends on how the spring back can be predicted in order to compensate it by tooling changes. Most of the applications relate to...