Solute drag in grain boundary migration and phase transformations

Abstract Cahn’s equation for solute drag has recently been applied to phase transformations but the method of application has been disputed. A new equation for solute drag is now proposed, which is more general and applies to multicomponent systems. It yields the same result for the migration of grain boundaries but a different result for phase transformations. It has the advantage of being equivalent to the approach based on the dissipation of Gibbs energy.