9.1 Freezing Point Depression(5) S.J.T.0. Phase Transformation and Applications Page 19/36 Liquid:the equilibrium phase is a liquid A- B solution Liquid Two phase region:L+S,pure solid A is in 单相区 equilibrium with a liquid solution At T1,pure solid A is in equilibrium with a liquid solution of composition xB L+S T Phase rule?For L+S region as a condensed system F=C-P+1=2-2+1=1 A XB.I XB→ B Fig.9.3 Portion of an A-B phase diagram Once T is specified,composition is specified,not amount SJTU Thermodynamics of Materials Fall 2011 ©X.J.Jin Lecture 14 Phase diagram IPhase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Fall 2011 © X. J. Jin Lecture 14 Phase diagram I Page 19/36 9.1 Freezing Point Depression (5) Fig. 9.3 Portion of an A-B phase diagram. Liquid: the equilibrium phase is a liquid A￾B solution Phase rule? For L+S region as a condensed system Two phase region: L+S, pure solid A is in equilibrium with a liquid solution At T1, pure solid A is in equilibrium with a liquid solution of composition xB,l. A B Tm T xB T1 Liquid xB,l L+S F = C − P +1 = 2 − 2 +1 =1 Once T is specified, composition is specified, not amount 单相区