Phase diagram information

The book begins with a chapter describing the history and growth of CALPHAD. This provides a useful point of departure for a more detailed account of the various strands which make up the CALPHAD approach. Chapters 3 and 4 then deal with the basic thermodynamics of phase diagrams and the principles of various experimental techniques. This is because one of basic pillars of the CALPHAD approach is the concept of coupling phase diagram information with all other available thermodynamic properties. It is a key factor in the assessment and characterisation of the lower-order systems on which the properties of the higher-... 

The massive task required that data be sorted into categories by some thirty editors. The first comprehensive publication to be released thus far is from the American Society for Metals (ASM International), entitled Binary Alloy Phase Diagrams." which contains up-to-date and comprehensive phase diagram information for more than 1850 alloy systems, representing the first major release of critically evaluated phase diagrams since 1969. 

According to the assessment of the phase diagram information by Romermann et al. [2000ROM/FEU], Tl2Se3(cr) probably does not exist and the thermodynamic properties estimated by Mills [74MIL] and reported by Terpilowski, Zaleska, and Gawel [68TER/ZAL] are therefore irrelevant. 

Ternary blends that comprise two immiscible polymers and a copolymer are of a particular interest. They not only represent an ideal model for studying compatibilization of polymer blends, but also they have found direct commercial applications. Phase diagram information can be found in reviews by Ajji and Utracki [1996, 1997] and in Chapter 2 in this Handbook. 

Lee] Lee, B.-J., Evaluation of Off-Diagonal Diffusion Coefficient from Phase Diagram Information , J. Phase Equilib., 22, 241-246 (2001) (Kinetics, Calculation, Theory, 9)... 

The only phase diagram information on the system Sc-Tb-Ge is due to Shpyrka (1990) who investigated ternary arc melted alloys annealed at 870 K in the ScGe2-TbGe2 quasibinary system by means of X-ray powder diffraction. The solubility of ScGea in TbGea extends to 6 at,% Sc. 

Let us consider the form of the phase diagram of water, shown in Figure 4.1, and the information that is incorporated into it. There are three phase equilibrium lines corresponding to the coexistence of liquid and solid, of liquid and vapor, and of solid and vapor. These curves meet at a single point where all three phases coexist, and it is called the triple point. This point is the one specific pressure, temperature, and (implicitly) volume at which this occurs. For water, the triple point occurs at a very low pressure. We will see that phase diagram information is related to equations of state, which in turn are related to inter-molecular interactions. Thus, laboratory measurement of phase behavior data provides information on certain intrinsic molecular properties related to intermolecular interaction. 

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