An experimental and computational study into strain localisation in beta-annealed Ti-6Al-4V

Abstract

Recent advances in microstructural characterisation techniques are revealing deeper insight into the plastic behaviour of polycrystalline metals. The use of digital image correlation (DIC) to visualise material deformation through slip band localisation is one such emerging technique. Not only does this technique visualise the contribution of microstructure on strain heterogeneity and strain patterns at the meso-scale, it also provides valuable information for the validation and development of computational models. These experimental techniques enable the development of improved crystal plasticity models with a focus on predicting strain localisation associated with slip traces. In this study, DIC was performed on β-annealed Ti-6Al-4V to investigate the strain patterns associated with macrozones (clusters of similar orientated grains). This was done to enhance computational capability into the influence of large prior-β grains on damage accumulation through the investigation of strain localisation. Simulations using Fast Fourier Transform crystal plasticity (CP-FFT) models were also conducted on the same experimental regions of interest to assess the ability to predict strain localisation.