Investigation of multiphase equilibria in the subsolidus of BaO–CoO–Fe₂O₃–Al₂O₃ system

¹ Ukrainian State University of Railway Transport, Department of Occupational Safety and Environmental Protection, Feyerbakh sq. 7, 61050 Kharkiv, Ukraine
² National Technical University “Kharkov Polytechnic Institute”, Department of Ceramics Technology, Refractories, Glass and Enamels, Kyrpychova str. 2, 61002 Kharkiv, Ukraine
³ Semon Kuznets Kharkiv National University of Economics, Department of Technology, Ecology and Security of Vital Activities, Nauky avenue 9-A, 61166 Kharkiv, Ukraine

^* Corresponding author: marina.sh.225@gmail.com

Abstract

One of the most important problems related to the development of new nonmetal materials and their performance characteristics is to predict the phase composition. The most comprehensive information on phase interactions and the thermodynamic stability of phase combinations is given by the state diagrams. The materials synthesized in the system subsolidus domain can be predicted the most accurately, because their sintering occurs without participation of the melt. Due to the above fact, the studies of the subsolidus structure of BaO – CoO – Fe₂O₃ – Al₂O₃ system are of great interest, because on the basis of this system we can obtain a huge amount of nonmetal materials with prescribed properties, for example ferrimagnetic materials to protect from electromagnetic radiation, because the system compounds have cementing, refractory and ferrimagnetic properties. To study the structure of BaO – CoO – Fe₂O₃ – Al₂O₃ system in detail the authors summed up already known data on the thermodynamic constants of system compounds. This allowed us to do the thermodynamic analysis of multiphase equilibrium processes that occur in the subsolidus of BaO – CoO – Fe₂O₃ – Al₂O₃ system that was used as a basis for the plotting of the state diagram for the subsolidus domain of the system. A promising field for the application of obtained data is the cement production technology. The produced cement can be used independently and as a binding material to produce special cements and materials that retain their properties when exposed to the action of high-frequency electromagnetic radiation.