Ternary eutectic temperature

A three-dimensional model of a ternary phase diagram with a ternary eutectic. T-i corresponds to the AB binary eutectic temperature, T2 to the AC binary eutectic temperature, T3 to the BC binary eutectic temperature, and T4 to the ABC ternary eutectic temperature. 

Ternary eutectics are also possible. The binary eutectic points of three mixtures are as follows for aminophenazone-phenacetin 82°C for aminophenazone-caffeine 103.5°C and for phenacetin-caffeine IZS C. The ternary eutectic temperature of aminophenazone-phenacetin-caffeine is 81°C. In this mixture the presence of aminophenazone and phenacetin can be detected by the mixed melting point... 

Figure 19 shows a microstructure of Al203 sintered with 0.05 wt % Y203 and 0.05 wt % MgO above the ternary eutectic temperature. The lack of entrapped porosity reported by Rossi and Burke [5S] is confirmed. The microstructure has a distinct shift in grain size distribution if one compares this structure with Fig. 13. It is hypothesized that MgO remains an effective grain growth inhibitor in the presence of the ternary eutectic...

At about 1300-1340 °C (binary eutectic temperature WC-Co 1310 °C ternary eutectic temperature W-Co-C 1275/80 °C) partial melting occurs, and more WC is dissolved until the eutectic concentration (54% Co and 46% WC) is reached [9.8]. A further increase in temperature results in additional dissolution of WC and complete melting of the binder phase. In this stage, rapid final densification occurs and the sintered body is practically pore-free. 

For slags exhibiting a transition in behavior, the transition temperature could usually be associated with a ternary eutectic temperature in the phase equilibrium diagram for the most closely related ternary system. 

A curved liquidus surface more complex than that shown in Figure 3.8 can be conveniently visualized with the help of a (hypothetical) infinitely flexible membrane stretched between points Ta-Tb-Tc and weighted down by small point-like spheres of different density at the positions of the eutectic points. The downward deflection of the membrane caused by these balls is proportional to their density, so that larger deflections correspond to lower binary and ternary eutectic temperatures. Here, the physical model ends as the membrane must have a peculiar property of being able to bulge between points of deflection to account for the convex curvature of the Hquidus surface and also the occurrence of saddles (cols), ridges, and dome-shaped surface areas, the positions of which are defined by the AUcemade fines (see above). 

Tan = 1550°C the binary eutectic temperatures 1362°C (quartz-diopside), 1270°C (diopside-anorthite), and 1368°C (quartz-anorthite) and the ternary eutectic temperature of 1200 °C. The composition of the ternary eutectic is 30 mass% quartz, 33 mass% diopside, and 37 mass% anorthite (Clark et al., 1962 Osborn and Tail, 1952). The ternary phase diagram discussed above refers to high-fired calcareous UMtic clays with the four components Si02, AI2O3, CaO, and MgO, but fails to incorporate an important fifth component such as Fe203. Hence, even more complex phase relations must be considered in appropriate multicomponent (quaternary, quinary, hexanary,... multinary) systems. 

Surface tension and density of liquid alloys have been studied by Moser et al. (2006). Measurements by maximum bubble pressure and dilatometric techniques were carried out in an extensive range of temperatures on liquid alloys close to the ternary eutectic Sn3 3Ag0 76Cu with different Sb additions, which decrease surface tension and density. The experimental data were discussed in comparison also with values calculated on the basis of different models. 

A typical example of this system might use the ternary eutectic LiF-LiCl-Lil, which melts at 341°C, and a cell operating temperature in the range 350-400°C. The cell would then have the form... 

Figure 16.2. Some phase diagrams, (a) The water end of the system potassium chloride and water, (b) The water end of the system sodium chloride and water, (c) The water end of the system magnesium sulfate and water the heptahydrate goes to the mono at 150°C, and to anhydrous at 200°C. (d) /3-methylnaphthalene and /S-chloronaphthalene form solid solutions, (e) Mixtures of formamide and pyridine form a simple eutectic, (f) These mixtures form binary eutectics at the indicated temperatures and a ternary eutectic at mol fractions 0.392 dibenzyl, 0.338 diphenyl, and 0.27 naphthalene.

For a number of years, thallium sulfate had been used in rodenticides. Some use of thallium has been made in connection with alloys for low-temperature applications, particularly for switches, seals, and thermometers. The ternary eutectic mercury-thallium-indium alloy has a freezing point of —63.3 JCt while the binary eutectic mercury-thallium alloy has a freezing point of — 60°C. These freezing points are considerably lower than that of mercury usually used for similar applications at higher temperatures. Mercury freezes at —38.87JC. 

The solubility of carbon in iron is reduced by the addition of phosphorus, but the temperature of formation of the eutectoid pearlite is not influenced by the presence of the phosphide. P. Goerens and W. Dobbelstein gave for the composition of the ternary eutectic E, Fig. 27, at 953°, l-96 per cent, of carbon, 6-89 per cent, of phosphorus, and 9145 per cent, of iron and J. E. Stead, respectively 1 92, 6 89, and 9149. In Fig. 26, A represents the iron-phosphorus eutectic, and B, the iron-carbon eutectic. They showed that when sat. solid soln. of iron phosphide in iron are heated or cooled they show no critical point at Ars, and the structure is not broken up even... 

The ternary invariant points (e.g., e and /in the above diagrams) that appear in a system without solid solution are either ternary eutectics or ternary peritectics. Whether it is eutectic or peritectic is determined by the directions of falling temperatures along the boundary curves. 

If an invariant point is the minimum point in temperature along all three boundary curves, it is a ternary eutectic. 

First, we discuss a simple ternary eutectic system without solid solution as shown above. The following figures show isothermal sections at a number of different temperatures ... 

At very low temperatures the Y-phase has the approximate formula FeMo412S6 and the solid solubility increases directly with temperature. At 973 °C, which is the temperature of the ternary eutectic, the Y-phase has its Fe-richest composition (Fei uMo4 03S6). 

In order to araise current yield of carbon phase it is advisable to use more low-melting electrolytes. For this purpose the electrolysis of C02 in the ternary eutectic Na,K,Cs Cl at temperature 500 C was carried out. In this system carbon current yield was arisen up to 80 % and the cathode product contained fullerenes phase (according to X-ray analysis) together with carbon phases obtained in NaCl - KC1 melt. 

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