上游充通大￥ e SHANGHAI JIAO TONG UNIVERSITY Chapter 9.Phase Diagram Ill Review: 是 Immiscibility:不溶性 Spinodal Points:拐点 Peritectic Phase diagram:包晶相图 Compounds:化合物 LV0VY7 AI JIAO TONG UNIV
Chapter 9. Phase Diagram III Review: Immiscibility： 不溶性 Spinodal Points：拐点 Peritectic Phase diagram:包晶相图 Compounds：化合物
上游充通大￥ SHANGHAI JIAO TONG UNIVERSITY 9.5 Immiscibility:Regular solution 4500 4000 m=17.D00md 3500 3000 2500 2000 1500 1000 白 500 025 0.5 0.75 8◆ ia) -100 T=800K,w=17.000imdl 1+2 200 300 400 ®3025 0.5 0.758.4 1 -500 TON u◆ 600 Figure 9.14 The miscibility gap in solid A-B solutions. 700 800 0.25 0.75 Figure 9.13 Plots of properties of mixing versus composition for regular solutions: (a)molar enthalpy and (b)molar Gibbs free energy
9.5 Immiscibility: Regular solution
上游充通大粤 SHANGHAI JIAO TONG UNIVERSITY 9.6 Spinodal points 1050 1000 line 750 0 -100 600 T=800K,w=17.000 J/mol 0.25 0.5 075 -200 The decomposition here will cause the increase of Gibbs free energy Figure 9.15 The miscibility gap,showing spinodal line. 300 and therefore is relatively not favored -400 -500 △Gm decrease upon decomposition -600 -700 △Gm increase upon decomposition -80 0 xB.1 0.25 0.5 0.75 XB,2 x8→
9.6 Spinodal points
上游充通大粤 SHANGHAI JIAO TONG UNIVERSITY 9.7 Peritectic phase diagrams Peritectic transformation A liquid phase and a solid phase can combine to form an entirely new solid phase Weight percent carbon 02 0.4 0.6 0.8 liquid +solid,=solid B 1538℃ L+6 0.741493 liquid +solid,=solid 1500 Fe 2.43 0.40 6+y L+7 相律？ 1400 1394℃ 1300 2 Fe Atomic percent carbon Figure 9.17 The binary phase diagram for carbon (graphite)and iron
9.7 Peritectic phase diagrams
上游充通大￥ SHANGHAI JIAO TONG UNIVERSITY 9.8 Compounds 1600 1414 Mg:Si L 1200 L+Si 1087 946.7 赵 L+Mg 56.5 800 L+Mg2Si L+MgzSi 649 638.8 Mg2Si+Si 1.38 Mg+Mg2Si 400 Mg 10 20 30 40 50 60 70 80 90 Si w(Si)/%
9.8 Compounds