PNNL

Abstract

We propose a phase-field model for modeling microstructure evolution during deformation twinning. Using a face-centered cubic aluminum as an example, the deformation energy as a function of shear strain is obtained using first-principle calculations. The gradient energy coefficients are fitted to the twin boundary energies and to the dislocation core energies. The elastic energy of twinned structures is included using the Khachaturyan’s elasticity theory. We simulated the twinning process under a number of fixed deformation magnitudes and predicted the microstructures.