Characterisation and assessment of titanium alloys after linear friction welding and under cyclic loading

This project will address fundamentals of fatigue crack initiation and fatigue crack growth resistance in titanium alloys after linear friction welding. Particular attention will be focused on defining limits of defect sizes and distributions that can be present after welding in terms of their effect on subsequent total fatigue life. This is likely to entail a detailed experimental programme of fatigue testing followed by in-depth characterisation and assessment of fatigue and fracture micro-mechanisms of crack initiation and crack growth using analytical transmission electron microscopy and scanning electron microscopy. Microstructural characterisation including underlying texture will also be an important aspect of the study in order that microstructure-processing- behaviour correlations can be used to provide input into models of fatigue behaviour to predict the in-service performance of components with confidence.