Ya. I. Kosov, V. Yu. Bazhin.
ABSTRACT:
Aluminum-erbium master alloy is destined to improve the physical and mechanical properties of aluminum alloys. Current energy intensive foreign technologies and absence of domestic technologies of preparation of Al-Er master alloy make it important to create a technology of the aluminothermic reduction of erbium compounds from chloride-fluoride melts. A thermodynamic analysis of the aluminothermic reduction of various erbium compounds has been carried out. Erbium fluoride was chosen as the preferred starting material, taking into account the physicochemical properties of the erbium compounds. The aluminothermic reduction of erbium fluoride in the salt mixture with sodium fluoride and potassium chloride, taking into account the formation of the intermetallic compound Al3Er, has a high thermodynamic probability. The thermodynamic values of the erbium complex compound have been determined by an indirect method, because of limited information. The аluminum-еrbium master alloys has been synthesized via aluminothermic reduction method in the ErF3-NaF-KCl melts with different ratio ErF3 /NaF and content of KCl in the temperature range 750–900 °C. The result of the investigation of microstructure and phase composition of the synthesized master alloys has been given. The investigation of phase composition of the flux used to synthesize the Al-Er master alloy has been carry out
KEY WORDS: master alloy, aluminum-erbium, aluminothermic reduction, flux, thermodynamic, microstructure, intermetallic compound, Al3Er.