Superplastic Forming of Aerospace Metallic Materials

The engineering application of superplastic forming (SPF) has been discussed with some typical examples of SPF parts in application fields classified into three groups. The first one is an application to integrated structures, which replace assembled structures consisting of a lot of detail parts and fasteners. In this case, considerable manufacturing cost saving and structural weight reduction can be achieved by decreasing parts count. The second one is an application to elaborate components of close tolerance, which replace machined parts. This kind of application becomes feasible due to the fact that SPF parts have as close tolerance as machined parts. In this case, not only material and manufacturing cost saving but structural weight reduction can be expected because of less limitation of minimum thickness of SPF than machining. The third one is an application to advanced materials with less workability like metal matrix composites and intermetallic compounds. SPF can be considered one of key technologies to promote application of these advanced materials to aerospace components making them plastic workable and cost competitive. In addition, basic technologies having been developed to promote engineering application of SPF and prospect of further advancement of SPF in the field of aerospace components in future has been briefly referred. Materials entioned include Ti-6Al-4V, 7475, 7075, and TiAl.