Preparation of Novel Al-Er Master Alloys in Chloride-Fluoride Melt

Abstract

Abstract. A novel Al-Er master alloy has been prepared through situ metallothermic reactions of NaErF 4 and aluminium melts. The compound NaErF 4 is formed as a result of the interaction of NaF and ErF 3 in the melt medium KCl. The metallothermic reactions produce erbium, which through low solubility in molten aluminium and forms intermetallic compound Al 3 Er. The microstructures of the Al-Er master alloy with different contents of the alloying metal has been investigated. The results showed that the Al-Er master alloy mainly consisted of phases of α-Al and Al 3 Er, that confirmed by the results of X-ray diffraction. Backscattered electron imaging of the Al-Er master alloy under a scanning electron microscope (SEM) revealed the presence of phase Al 3 Er, which crystallized in the eutectic composition [Al+Al 3 Er]. The observed microstructure is explained according to the eutectic reaction in an Al-Er phase diagram. The preparation of Al-Er master alloy by the metallothermic reduction method will allow to reduce energy consumption for master alloy production and to reduce the cost of aluminium alloys alloyed with Er through the novel master alloy.

Microstructural Master Alloys Features of Aluminum–Erbium System

“…In a series of works carried out by us [39,40] on the development of technology for obtaining aluminum-erbium master alloys, a method of metallothermic reduction of erbium compounds was used in which the formation of the master alloy structure was initiated by aluminothermic reduction of erbium-containing complex compounds formed during the melting of the initial salt mixture (flux). In this case, the production of aluminum -erbium master alloys is associated with the course of high-temperature heterogeneous physicochemical processes based on the difference in the affinity of the reducing metal and the metal being reduced to oxygen or to the elements that make up the flux.…”