Validation of In718 SPF and DB processes for the design of aircraft engine parts

This paper deals with a combined superplastic forming and diffusion bonding (SPF and DB) process in an Inconel superalloy (In718). The steps of the validation of this process prior to its implementation at a production scale are covered in the paper. A great effort has been dedicated to the optimization of the SPF finite element (FE) simulations, which are an essential part at both the design and manufacturing stages. This task has been carried out by taking into account the program parameters and the material model, in order to minimize a given error function. The material model was generated through lab scale trials, and introduced in ABAQUS FE code through subroutines. Fine grained (standard SPF) In718 presents an acceptable superplastic behaviour which allows for the design of complex components involving localized high strain areas, where final sheet thickness predictions become essential for the design of a component.