Rotational partitioning at two-phase interfaces

The partitioning of rotations is considered for two-phase interfaces. In the isotropic, linear elastic approximation, the rotations associated with tilt components of interface dislocations and disconnections partition equally to the two phases. With anisotropic elasticity and with nonlinearities, the partitioning is unequal. Results for linear anisotropic elasticity, average anisotropic elasticity and nonlinear effects as incorporated in an atomistic simulation are compared. The results also apply to most cases of single phase grain boundaries. The results of the atomistic simulations are as predicted in the topological theory of phase transformation. The results have implications for habit plane determination in phase transformations, for the relief of coherency stresses at interfaces, and for boundary conditions in atomistic simulations.