Diffusion processes during reaction synthesis of iron-tin intermetallic compounds

For citation: Bolkunov G.A., Novotelnova A.V., Popov N.S., Bochkanov F.Yu., Karpenkov D.Yu. Diffusion processes during reaction synthesis of iron-tin intermetallic compounds. Journal of International Academy of Refrigeration. 2026. No 1. p. 62-68. DOI: 10.17586/1606-4313-2026-25-1-62-68. (in Russian)

Abstract
The growing demand for permanent magnets used in environmentally friendly energy systems, as well as in hybrid and electric vehicle drives, has renewed interest in the development of new magnetic materials that do not contain rare-earth elements. Materials based on the binary iron-tin system produced by reaction synthesis have therefore attracted considerable research attention. In this work, we investigate diffusion processes occurring during the reaction synthesis of magnetic materials based on iron-tin intermetallic compounds with enhanced thermomagnetic properties. Heating of the reaction zone is achieved by passing a high-density electric current. We analyze the influence of the geometric dimensions of the reaction zone on thermal regimes and on the intensity of diffusion processes in the iron-tin system during electrothermal treatment. The study is carried out using mathematical modeling based on the finite element method. The applied modeling approach allows to consider thermal, electrical, and mass transfer processes occurring in the reaction crucible, taking into account the spatial distribution of components and the processing conditions of the crucible. Numerical data on tin diffusion into iron during the reaction synthesis of iron-tin intermetallic compounds under prolonged electrothermal exposure are analyzed. It has been found that variations in the geometric dimensions of the crucible have a significant effect on temperature regimes and on the activity of diffusion processes. Maintaining appropriate crucible proportions ensures a coordinated distribution of electric current lines within the crucible and a prescribed synthesis temperature regime, thereby enabling the achievement of reproducible results. The obtained results can be used for the analysis of experimental data and for predicting the conditions required for the synthesis of new functional magnetic materials.