Phase S.J.T.U. Phase Transformation and Applications Page 13/45 Phase:a homogeneous,physically distinct,and mechanically separable portion of matter present in a nonhomogeneous physical chemical system. <Webster's Dictionary> SJTU Thermodynamics of Materials Fall 2010 X.J.Jin Lecture 13 Phase RulePhase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Fall 2010 © X. J. Jin Lecture 13 Phase Rule Page 13/45 Phase Phase: a homogeneous, physically distinct, and mechanically separable portion of matter present in a nonhomogeneous physical chemical system. <Webster’s Dictionary>