Phase equilibrium S.J.T.U. Phase Transformation and Applications When a material composed of a single component exists in different physical states,the two states will be at equilibrium when the molar Gibbs free energies of the two states are equal. SJTU Thermodynamics of Materials Spring2007©X.J.Jin Lecture 7 equilibrium IPhase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Spring 2007 © X. J. Jin Lecture 7 equilibrium I Phase equilibrium When a material composed of a single component exists in different physical states, the two states will be at equilibrium when the molar Gibbs free energies of the two states are equal