Internal strain and texture development during twinning: Comparing neutron diffraction measurements with crystal plasticity finite-element approaches

Different approaches to the modeling of twinning are examined within the framework of a crystal plasticity finite-element code. The model predictions are compared with in situ neutron diffraction experiments previously carried out on zirconium and magnesium alloys. The experiments are used to evaluate different model assumptions regarding the stress state inside newly formed twins at inception, as well as different assumptions concerning the interaction between twin and parent grain during subsequent twin growth. In particular the relaxation in some grain orientations that is experimentally observed, and is associated with twin-induced stress relief, can be captured by the model under appropriate assumptions.