Study of the Fe-Si-Al-Ba system using the thermodynamic-diagrammatic analyses method

Abstract

The article presents the results of a study of the thermodynamic-diagram analysis of the Fe-Si-Al-Ba multicomponent system, where, on the basis of thermodynamic data, the boundary ternary systems of the basic four-component Fe-Si-Al-Ba system are constructed. As a result, it was determined that the system consists of 12 elementary tetrahedra. For each of the tetrahedra, analytical equations are determined, with the help of which it is possible to establish the location in the factor space of the general system of the compositions of various metal melts with the calculation of their normative phase compositions. The correctness of the breakdown into elementary tetrahedra can be seen due to the volumes of the same tetrahedra, where the sum of these volumes is equal to one (1.00000). The quasi-volumes in the system Fe-Si-Al-Ba, simulating the compositions of the resulting metal products during the smelting of an alloy of ferrosilicoaluminum with barium in the process of reduction, have been established. As a result, it turned out that the Fe-Si-Al-Ba system does not include ternary and quaternary compounds, with the exception of interstitial solid solutions containing Fe-Si and Fe-Al phases doped with barium, as well as silicon-barium-aluminum containing eutectic. In this case, the region of the composition of the alloy with a barium content of 8-10% will be the most optimal. Further, with an increase in the concentration of barium in the alloy above 10%, it leads to the loss of barium with atmospheric oxygen, and also leads to a violation of the melting process.