Computational thermodynamics in electric current metallurgy

A priori derivation for the extra free energy caused by the passing electric current in metal is presented. The analytical expression and its discrete format in support of the numerical calculation of thermodynamics in electric current metallurgy have been developed. This enables the calculation of electric current distribution, current-induced temperature distribution and free energy sequence of various phase transitions in multiphase materials. The work is particularly suitable for the study of magnetic materials that contains various magnetic phases. The latter has not been considered in literature. The method has been validated against the analytical solution of current distribution and experimental observation of microstructure evolution. It provides a basis for the design, prediction and implementation of the electric current metallurgy. The applicability of the theory is discussed in the derivations.