An internal variable model of macroscopic twin boundary dynamics

Depending on whether the experiments are quasi-static or fast dynamics, the measured twin boundary velocity values range from zero to the material’s sound speed. The twin boundary velocity is not yet predicted theoretically in the continuum mechanics framework. The extension of continual description is provided in the paper by means of internal variables. It is shown that a diffusional slow motion of twin boundaries can be represented using a single internal variable. The dual internal variable technique is employed for the description of the fast dynamics of twin boundaries.