Verification of Phase Diagrams by Three-Dimension Computer Models

Such known programs as Lukas Program, ThermoCalc, ChemSage, FACTSage, MTDATA, PanEngine, PANDAT are created for the calculations of phase equilibria. Thanks to them itbecame possible the use of more realistic models of the thermodynamicproperties of phases, the calculation of phase diagrams in the complex two-component systems and the systems with the large number of components. The CALPHAD-method, which makes possible to generalize and to refine within the framework information about the phase equilibria and the thermodynamics of phases for one model, is most claimed today. It is effective means for decreasing the volumes of the experiments, necessary for understanding of phase transformations in the alloys and the ceramics. The CALPHAD ideology became the powerful means of theoretical studies and obtaining of adequate information about the phase equilibria. 

Thermodynamic properties and phase diagrams for the technologically important multi-component materials can be predicted with its use. The reliable thermodynamic descriptions of two-component systems are the basis of the data bases with such characteristics. However, the CALPHAD application is limited by a deficiency in reliable thermodynamic data and the weak possibilities of the visualization of three-dimensional objects. In addition to this, using of thermodynamic methods of the states diagram calculating is hindered by the need of evaluating the thermodynamic properties of phases (in the absence of experimental data) and the agreement of experimental data of phase equilibria with the thermodynamic models. The innovation technology of assembling the space models of multidimensional phase diagrams from the entire totality of the geometric images corresponding to them is proposed: “To decode the diagrams topology the schemes of uni- and invariant states had been elaborated. This sort of schemes with phase’s routes designations makes possible to calculate the number of phase regions, surfaces and to know a type of every surface (plane, ruled or unruled surface). Detailed analysis of T-x-y diagrams geometrical constructions had been carried out with their aid, and their computer models had been designed” .(Read more)