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

Aided by advances in modelling tools and computational power, one is now ab le to numerically investigate grain and sub-grain heterogeneities in polycr ystalline aggregates containing enough grains to form a representative samp le of the relevant orientation distribution functions. Materials with multi ple ductile phases, especially those with phases having large strength diff erences or with strongly anisotropic single-crystal constitutive responses, tend to undergo deformations with greater heterogeneity at the scale of gr ains and are good candidates for numerical study. Interest in model predict ions of grain and sub-grain deformation heterogeneities, and thus lattice o rientation variations, has been fuelled by the automation of experimental t echniques, such as electron back-scatter diffraction scanning. These techni ques make it possible to obtain a rich characterization of the spatial arra ngement of lattice orientations in a sample. Simulation results include pre dictions of grain and sub-grain deformation heterogeneities, and emphasis i s placed on quantities which may be compared to experimentally measured val ues. 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.