Anna Zelenaya

Specific features of the crystallization of melts in systems with a transition from syntectic equilibrium to monotectic equilibrium

A technology has been proposed for implementing the computer design of phase diagrams and their investigation with the kinematic specification of surfaces by using the T-x-y diagram with a monovariant syntectic equilibrium and a solid-phase solubility as an example. The specific features of the crystallization upon transition from syntectic equilibrium to monotectic equilibrium have been considered, and surfaces with a sign reversal of the mass increment and material balance for a three-phase region have been constructed.

Computer model of a T-x-y diagram for a ternary system with monotectic monovariant equilibrium

Computer design with the kinematic specification of nonlinear and ruled surfaces is proposed for a T-x-y diagram of a ternary system with monotectic monovariant equilibrium. The three-dimensional model makes it possible not only to design any iso-or polythermal section but also to solve mass-balance problems associated with computer design of heterogeneous materials.

Phase trajectories in CaO-Al2O3-SiO2 melts

A technique for constructing a phase diagram of the CaO-Al2O3-SiO2 system on a computer using the kinematic approach to describe surfaces is proposed. The geometric structure of the diagram and its phase regions is described. Crystallization paths are considered for different parts of the diagram.

Li,Na,Rb,La||F System for Molten Salt Reactor: 3D and 4D Computer Models

A computer model of LiF-KF-LaF3 system as one of the bounding systems of LiFNaFRbFLaF3 system is presented. The phase regions structures, horizontal and vertical sections are analyzed. The computer simulation of T-x-y diagrams can be used as an instrument to solve different applied tasks for molten salt reactor application.

Crystallization paths and microstructures in ternary oxide systems with stoichiometric compounds

The problems of computer model simulation of CаO-SiO2-Al2O3 system are considered. The crystallization scheme and sets of microstructure elements are analyzed for the fields of liquidus CaO, 3CaO*SiO2, 3CaO*Al2O3. The concentration fields both with individual set of microstructure elements and the fields without the unique crystallization scheme and microstructure set were found. The crystallization stages for given compositions are illustrated by the mass balance diagrams.

T–x–y Diagram of the MgO–SiO2–Al2O3 System: Computer Model Assembly

A computer phase diagram model is constructed for the MgO–SiO2–Al2O3 system, giving its complete geometric description and containing 10 liquidus surfaces, a liquid–liquid phase separation surface, 75 ruled surfaces at the boundaries between two-phase and three-phase fields, 11 horizontal four-simplex at invariant temperatures, 21 two-phase fields, and 30 three-phase fields. The description of surfaces and three-phase fields is presented.

Reference Book on the Oxide Systems Space Diagrams as a Tool for Data Mining

The Reference Book of Ternary Oxide Systems phase diagrams computer models is presented. Its computer models of T-x-y diagrams give a possibility to calculate the mass balances at any temperature, to observe crystallization history and the process of microstructure forming at different crystallization stages. The investigation of concentration fields with the different phase constituents on the T-x-y diagram projection by means of its computer model is considered. Phase diagram of CaO-SiO2-Al2O3 system is used as an example.

Phase equilibria in the NaF-LiF-LaF3 system

The NaF-LiF-LaF3 system was studied by differential thermal and X-ray powder diffraction analyses. In the system, there are two ternary invariant points, a eutectic (580 ± 2°C, 44.0 mol % NaF, 42.0 mol % LiF, 14.0 mol % LaF3), and a peritectic (595 ± 2°C, 45.0 mol % NaF, 39.0 mol % LiF, 16.0 mol % LaF3). The ternary peritectic point results from the intersection of the crystallization fields of LiF, LaF3, and NaLaF4.

Crystallization paths in SiO2-Al2O3-CaO system as a genotype of silicate materials

The phases trajectories in the fields of primary crystallization of cristobalite (SiO2cr), tridymite (SiO2tr), mullite (3Al2O3-2SiO2) and in a field of liquid immiscibility are analyzed on a basis of computer model for T-x-y diagram of SiO2-Al2O3-CaO system. The concentration fields with unique set of microconstituents and the fields without individual crystallization schemes and microconstituents are revealed.

Solidification Paths within the Ceramic Systems

The aim of this work is to assemble the computer models of phase diagrams (PD) for the typical ternary systems and to examine the processes of crystallization on its base. Spatial schemes of mono-and invariant equilibria have been used for it. Analysis of concentration fields, obtained by the projection of the surfaces on the Gibbs triangle, allows establish the boundaries of phase regions (located above the considered fields), the sequence of phase transformations and microstructural elements for the solidification of the initial melt at equilibrium condition. Concentration fields have been analyzed by means of mass balances for their centers of masses. Based on this technology, the research identifies concentration fields with coinciding sets of phase reactions and microconstituents, and the fields with individual characteristics.