Estimating residual stress levels in inertia friction welded Ni-based superalloy assemblies for enhanced production process modelling

Determining residual stresses in welds is fundamental in ensuring long-term resilience of safety critical joints. Inertia friction welds experience severe localised thermo-mechanical states, posing a specific set of challenges that complicate post weld state prediction. While the evolution of material structure under such aggressive conditions has received a great deal of attention, detailed analysis of residual stresses (particularly in industry relevant components) is lacking. Specific machine characteristics (tooling compliance, for example), initial component geometry, and alignment are suspected to be highly influential in developing non-axisymmetric residual stresses. The proposed project will support a comprehensive holistic analysis of an inertia friction welding relevant assembly. Coordinate-measuring machine readings have been recorded for a collection of components pre and post weld, allowing for a precise tracking of geometry. These results, along with a detailed machine and material model, will allow for advanced predictions of the inertia friction welding process and the enhanced estimation of post weld condition. Residual stress measurements gathered at ISIS Engin-X in this project will provide vital validation for this modelling exercise, enabling improved industry relevant understanding of the process and refinement of key processing variables.