Binary eutectics

Figure 2.5 Free energy of mixing for solid and liquid phases at various temperatures (a-e) and resulting temperature-composition phase diagram for a slightly soluble eutectic binary component system (f). From O. F. Devereux, Topics in Metallurgical Thermodynamics. Copyright 1983 by John Wiley Sons, Inc. This material is used by permission of John Wiley Sons, Inc.

Figure 6-2. a) T-N, and b) G-N, diagram of an eutectic binary system. The reaction path after undercooling is indicated by an arrow. 

Figure 2.2 Phase diagram for a hypothetical eutectic binary system. There are three single-phase fields (a, fi, and L) and three two-phase fields (a + 3, a + L, and 3 + L).

CRYSTAL GROWTH OF ICE-I/HYDRATE EUTECTIC BINARY SOLUTIONS... 

Fig. 2.3-4 Phase diagram of a eutectic binary system with total immiscibility in the two sohd phases left), phase diagrams of various types of binary systems with perfect (Type I) or partial (Type II -V) miscibility in the solid phase (right)...

P8.ll Is it, at least theoretically possible that a eutectic binary mixture with liquid-liquid immiscibility shows a eutectic composition inside the miscibility gap ... 

Systems with low or no mutual solubility of the components in solid (eutectic). Binary compoimds do not occur (E = 5A, 6A element). 

Analogous to ternary systems, a quaternary system can be represented in a three-dimensional prism, but having a square as prism base with the four components at the comers. An example is given in Figure 3.6a for four arbitrary components A, B, C, and D. Again, only simple eutectic binary systems A/B, B/C, C/D, and A/D are assumed. In order to simplify the interpretation of such quaternary phase equilibria, as for ternary systems, usually isothermal slices of the three-dimensional representation of the phase diagram are considered. 

There is a considerable amount of fatigue data for the eutectic and off-eutectic binary Sn-Ag... 

Kozina A, Sagawe D, Diaz-Leyva P, Bartsch E, Palberg T (2012) Polymer—enforced crystal-hzation of a eutectic binary hard sphere mixture. Soft Matter 8 627-630... 

A large number of thermodynamic studies of binary systems were undertaken to find and determine eventual intermolecular associations for thiazole Meyer et al. (303, 304) discovered eutectic mixtures for the following systems -thiazole/cyclohexane at -38.4°C, Wt = 0.815 -thiazole/carbon tetrachloride at -60.8°C, Mt = 0.46 -thiazole/benzene at -48.5°C, nr = 0.70. 

Alloys. GaUium has complete miscibility in the hquid state with aluminum, indium, tin, and zinc. No compounds are formed. However, these binary systems form simple eutectics having the following properties ... 

Binary Alloys. Aluminum-rich binary phase diagrams show tliree types of reaction between liquid alloy, aluminum solid solution, and otlier phases eutectic, peritectic, and monotectic. Table 16 gives representative data for reactions in tlie systems Al—Al. Diagrams are shown in Figures 10—19. Compilations of phase diagrams may be found in reference 41. 

Al—Li. Ahoys containing about two to three percent lithium [7439-93-2] Li, (Fig. 15) received much attention in the 1980s because of their low density and high elastic modulus. Each weight percent of lithium in aluminum ahoys decreases density by about three percent and increases elastic modulus by about six percent. The system is characteri2ed by a eutectic reaction at 8.1% Li at 579°C. The maximum soHd solubiHty is 4.7% Li. The strengthening precipitate in binary Al—Li ahoys is metastable Al Li [12359-85-2] having the cubic LI2 crystal stmcture, and the equhibrium precipitate is complex cubic... 

Eutectics melting at about —30, —47, and —40° C are formed in the binary systems, cesium—sodium at about 9% sodium, cesium—potassium at about 25% potassium, and cesium—mbidium at about 14% mbidium (34). A ternary eutectic with a melting point of about —72°C has the composition 73% cesium, 24% potassium, and 3% sodium. Cesium and lithium are essentially completely immiscible in all proportions. 

The distribution-coefficient concept is commonly applied to fractional solidification of eutectic systems in the ultrapure portion of the phase diagram. If the quantity of impurity entrapped in the solid phase for whatever reason is proportional to that contained in the melt, then assumption of a constant k is valid. It should be noted that the theoretical yield of a component exhibiting binary eutectic behavior is fixed by the feed composition and position of the eutectic. Also, in contrast to the case of a solid solution, only one component can be obtained in a pure form. 

A series of experiments have been undertaken to evaluate the relevant thermodynamic properties of a number of binary lithium alloy systems. The early work was directed towards determination of their behavior at about 400 °C because of interest in their potential use as components in molten salt batteries operating in that general temperature range. Data for a number of binary lithium alloy systems at about 400 °C are presented in Table 1. These were mostly obtained by the use of an experimental arrangement employing the LiCl-KCl eutectic molten salt as a lithiumconducting electrolyte. 

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