Contents of Today S.J.T.0. Phase Transformation and Applications Page 1/34 Review previous Immiscibility Spinodal Points Compounds etc. Conclusion Remarks Examples SJTU Thermodynamics of Materials Fall 2011 @X.J.Jin Lecture 15 Phase Diagram ll
Phase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Fall 2011 © X. J. Jin Lecture 15 Phase Diagram II Page 1/34 Contents of Today Review previous Immiscibility Spinodal Points Compounds etc. Conclusion Remarks Examples
Review of Last S.J.T.U. Phase Transformation and Applications Page2/34■ ·The lever rule Simple eutectic diagram ·Cooling curves SJTU Thermodynamics of Materials Fall 2011 @X.J.Jin Lecture 15 Phase Diagram ll
Phase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Fall 2011 © X. J. Jin Lecture 15 Phase Diagram II Page 2/34 Review of Last • The lever rule • Simple eutectic diagram • Cooling curves
Binary System S.J.T.0. Phase Transformation and Applications Page334■ Degrees of freedom available in the system(F): F=C-P+1 F=C-P+2 F:the number of system variables that we may freely vary,or arbitrarily fix C:components P:phase C=2 P=1,F=2 单相区 P=2,F=1 平衡线包围的两相区 P=3,F=0 三相平衡线 SJTU Thermodynamics of Materials Fall 2011 @X.J.Jin Lecture 15 Phase Diagram ll
Phase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Fall 2011 © X. J. Jin Lecture 15 Phase Diagram II Page 3/34 Binary System Degrees of freedom available in the system (F): F: the number of system variables that we may freely vary, or arbitrarily fix C: components P: phase F = C − P + 2 C = 2 3, 0 2, 1 1, 2 = = = = = = P F P F P F F = C − P +1 单相区 平衡线包围的两相区 三相平衡线
9.1 Freezing Point Depress4ion(4) S.J.T.0. Phase Transformation and Applications Page 4/34 稀溶液的依数性 Liquid Liquid T→x Tm (melting temperature) L+S T T Solid A XB.1 XB→ B XB L(T-T) RT △T=Tm-T ln(1-z)=-z small z SJTU Thermodynamics of Materials Fall 2011 X.J.Jin Lecture 15 Phase Diagram ll
Phase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Fall 2011 © X. J. Jin Lecture 15 Phase Diagram II Page 4/34 9.1 Freezing Point Depress4ion (4) 2 ( ) m m B RT L T T x − = z z small z T Tm T − = − Δ = − ln(1 ) 稀溶液的依数性 T ↔ x T Liquid Tm (melting temperature) Solid A B Tm T xB T1 Liquid xB,l L+S
9.2 The Lever Rule (1) S.J.T.0. Phase Transformation and Applications Page 5/34 In a two-phase region of a condensed system,if the overall composition is given,the quantities of the various phases can be calculated,beside to the the composition. Liquid F=fraction liquid Fs=fraction solid L+S F Fs=1,and a mass balance FXB-XBs F= XB-XB.s (XB-XB,s） FS XBI-XB XBI-XB.S A B XB.S XB XB.1 XB→ Fig.9.4 Illustration of the lever rule. SJTU Thermodynamics of Materials Fall 2011 X.J.Jin Lecture 15 Phase Diagram ll
Phase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Fall 2011 © X. J. Jin Lecture 15 Phase Diagram II Page 5/34 9.2 The Lever Rule (1) In a two-phase region of a condensed system, if the overall composition is given, the quantities of the various phases can be calculated, beside to the the composition. Fig. 9.4 Illustration of the lever rule. Fl=fraction liquid FS=fraction solid Fl+ FS=1, and a mass balance B l B B B s S x x x x F F − − = , 1 , B l B S B B s x x x x F , , , 1 − − = B xB A Tm T xB,S xB xB,l T1 Fig. 9.4 Illustration of the lever rule. B xB A Tm Liquid xB,l L+S xB,S xB ( ) B B,S x − x ( ) B,l B x − x Fig. 9.4 Illustration of the lever rule