FactSage Modules
The module



Click on Download Phase Diagram Slide Show (pdf presentation - 53 pages) for detailed information on the Phase Diagram Module.

Phase Diagram is a generalized module that permits one to calculate, plot and edit unary, binary, ternary and multicomponent phase diagram sections where the axes can be various combinations of T, P, V, composition, activity, chemical potential, etc. The resulting phase diagram is automatically plotted by the Figure module. It is possible to calculate and plot: classical unary temperature versus pressure, binary temperature versus composition, and ternary isothermal isobaric Gibbs triangle phase diagrams; two-dimensional sections of a multi-component system where the axes are various combinations of T, P, composition, activity, chemical potential, etc.; predominance area diagrams (for example Pso2 vs Po2) of a multicomponent system (e.g. Cu-Fe-Ni-S-O) where the phases are real solutions such as mattes, slags and alloys; reciprocal salt phase diagrams; etc.

The calculation of the binary temperature versus composition phase diagram for the CaO-SiO2 system is shown in Figs. 2 and 3 In the Phase Diagram module the system components (CaO, SiO2) are first entered in the Reactants Window (Fig. 2 top). Then the type of phase diagram is defined in the Variables Window (Fig. 2 bottom) where the user selects the type of diagram (Y vs X, or Gibbs triangle), the type of axes (composition, activity and chemical potential), the possible composition variables, and the limits and constants of the phase diagram. Data from the compound and solution databases are offered as possible product phases in the Menu Window (Fig. 3 top). In the case of CaO-SiO2, the slag solution phase (FACT-SLAG) and all pure solids (including those outside the plane CaO-SiO2) are selected as possible product phases. By clicking on the ‘Calculate >>’ button the phase diagram is automatically calculated and plotted in real time (Fig. 3 bottom). When the calculation is complete the Figure module uses the graph as a dynamic interface. By pointing to any domain, tie lines and stable phases are automatically labeled. Optionally the figure can be manipulated: tie lines can be inserted in the plot, the equilibrium compositions and phase amounts at any point on the diagram can be calculated and shown in a table, and the diagram can be edited (add experimental data points, text, change font and colors etc.). Examples of edited diagrams are shown later.

The versatility of the choice of axes in the Variables Window enables one to generate many different types of phase diagrams. Fig. 4 is a classical isothermal predominance area diagram for the Cu-SO2-O2 system. The system components are Cu, SO2, O2; the axis variables are log10(Pso2) and log10(Po2) and the temperature is set constant; the possible phases in the phase diagram are gas and stoichiometric solids taken from the FACT compound database. This diagram may be compared to the one produced by the Predom module for the same system.

Unlike the Predom module, Phase Diagram can produce predominance area diagrams that also include data from the solution databases. Fig. 5 shows the log10(Po2) vs Cr/(Cr+Fe) phase diagram at 1573 K where the system components are Fe, Cr and O2. The possible phases are the gas and various real solutions taken from the FACT (oxides) and SGTE (alloys) databases. Fig. 6 is the input/output for an isopleth of T(C) vs TiO2/(FeO+TiO2) ratio at 50 mol % Fe in the FeO-TiO2-Fe system again using both FACT and SGTE solution databases. An example of the interactive power of Phase Diagram is the equilibrium calculation shown in Fig. 7 where the user has first selected the phase equilibrium mode and then pointed and clicked at the coordinates 1450ºC and TiO2/(FeO+TiO2) = 0.7. Note, these results would be identical to a calculation with the Equilib module at 1450ºC and 1 atm where the reactants are 0.7 TiO2 + 0.3 FeO + excess Fe.

Fig. 8 is the input/output for a Gibbs ternary section of the CaO–Al2O3–SiO2 system at 1600ºC using FACT data.

The calculated diagrams can be stored as figure (*.fig) files, edited by the Figure module, and exported as *.bmp, *.emf and *.wmf files. Examples of the combined use of the Phase Diagram, Equilib and Figure modules to generate phase diagrams are shown in figures 9 to 15.

Fig. 1 - Phase Diagram Module


Fig. 2 - Phase Diagram Module - CaO-SiO2 system.
Top: Components Window - entry of CaO and SiO2,
Bottom: Variables Window - selection of T(K) and X(SiO2) axes.
Figure 2

Fig. 3 - Phase Diagram Module - CaO-SiO2 system.
Top: Menu Window - selection of the possible products.
Bottom: Figure Window - resulting binary CaO-SiO2 phase diagram.

Figure 3

Fig. 4 - Phase Diagram - Cu-SO2-O2 system.
Top: selection of the log1010(Pso2) and log10(Po2) axes at 1000K.
Bottom: the resulting predominance area diagram.

Figure 4


Fig. 5 - Phase Diagram - Fe-Cr-O2 system.
Top: selection of FACT(oxide) and SGTE(alloy) solution phases.
Bottom: resulting log10(Po2) vs Cr/(Cr+Fe) phase diagram at 1573K.

Figure 5

Fig. 6 - Phase Diagram - FeO-TiO2-Fe System.
Top: selection of the axes at constant Fe content.
Bottom: resulting T(C) vs TiO2/(FeO+TiO2) isopleth at 50 mol% Fe.

Figure 6

Fig. 7 - Phase Diagram - FeO-TiO2-Fe system.
Example of the phase equilibrium mode calculation at the coordinates 1450ºC and TiO/(FeO+TiO2) = 0.7.



Fig. 8 - Phase Diagram - CaO-Al2O3-SiO2 system.
Top: selection of the Gibbs triangle format, axes and temperature.
Bottom: resulting CaO-Al2O3-SiO2 ternary phase diagram at 1600°C (the labels have been edited).

A variety of calculated phase diagrams - some edited and enhanced via the Figure Module (labels added, etc.) – are shown in Figs 9 to 15.

Fig. 9 - Phase Diagram Module - Fe-Cr binary phase diagram: graphical output.

Fig. 10 - Phase Diagram Module - Fe-C-W system at 5 wt% W: graphical output.



Fig. 11 - Phase Diagram Module - Fe-Cr-V-C system: graphical output.



Fig. 12 - Phase Diagram - Zero Phase Fraction (ZPF) Lines.



Fig. 13 - Phase Diagram - FactSage Fe-Cr-V-C system. Mass fraction V versus mass fraction W isopleth at 0.3 wt.% C and 850°C calculated from SGTE data by Phase Diagram and editing the output in the Figure Module.

Figure 5

Fig. 14 - Phase Diagram - FactSage NaF-NaCl-CaF2-CaCl2 reciprocal system. The liquidus projection was calculated from FACT data by editing the results and ouputs from the Equilib, Phase Diagram and Figure modules.

Figure 6

Fig. 15 - Phase Diagram - NaCl-KCl-MgCl2 ternary system. The liquidus projection was calculated from FACT data by editing the results and outputs and from Equilib, Phase Diagram and Figure modules.



 

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Modified : December 4, 2010