On the spatial arrangement of lattice orientations in hot-rolled multiphase titanium

Aided by advances in modelling tools and computational power, one is now able to numerically investigate grain and sub-grain heterogeneities in polycrystalline aggregates containing enough grains to form a representative sample of the relevant orientation distribution functions. Materials with multiple ductile phases, especially those with phases having large strength differences or with strongly anisotropic single-crystal constitutive responses, tend to undergo deformations with greater heterogeneity at the scale of grains and are good candidates for numerical study. Interest in model predictions of grain and sub-grain deformation heterogeneities, and thus lattice orientation variations, has been fuelled by the automation of experimental techniques, such as electron back-scatter diffraction scanning. These techniques make it possible to obtain a rich characterization of the spatial arrangement of lattice orientations in a sample. Simulation results include predictions of grain and sub-grain deformation heterogeneities, and emphasis is placed on quantities which may be compared to experimentally measured values. Results for the deformation of titanium in the two-phase regime show a relationship between spatial correlations of the misorientation structure and both crystallographic and sample directions.