Microstructural characteristics and computational investigation on electron beam welded Ti-6Al-4 V alloy

A microstructural characterisation and computational modelling framework for simulating the coupled thermal-mechanical cycles with two different initial parent microstructures, and their impact upon the emerging microstructure features including β grain size and phase volume fractions during electron beam welding (EBW) of Ti-6Al-4 V (Ti64) alloy is presented. Ti64 plates (measuring 5.5 mm in thickness) with different thermal processing have been electron beam welded using differing process parameter sets. These experimental welds have been fully characterised to provide information on the effect that a prior heat treatment has upon the microstructural evolution caused by the EB welding. Microstructure characterisation was investigated using both light microscopy and scanning electron microscopy. The results from this microstructure characterisation have been used to identity physically-based parameters required for microstructure predictions.