Modelling and simulation of the inertia friction welding of shafts
The commercial materials forming package DEFORM-2D is used to model the inertia friction welding (IFW) process with particular reference to aero-engine mainline drive shafts. Both representative and predictive modelling techniques are presented, and models are described for the welding of identical and dissimilar material/geometry combinations. The range of material properties required for the models are discussed and details of the tests carried out to produce suitable material data are included. Case studies involving Inconel 718 and AerMet 100 are presented. The phase transformations in a high-strength aerospace steel are included in the model and their effects on residual stresses are presented. Temperature profiles are compared with experimental thermocouple measurements and the models are also compared with upset and rotational velocity data collected during welding. The DEFORM-2D software in conjunction with a friction law coded into a subroutine are shown to be suitable for modelling the IFW process between similar and dissimilar shaft materials. Results highlight the importance of the inclusion of the volume change associated with the martensite transformation on the residual stresses generated during the post-weld cooling of IFW joints.