Liquidus projection of Al-rich corner of the ternary Al–Fe–U system

Abstract

Microstructures of the solidified Al–Fe–U ternary alloys have been examined using optical and scanning electron microscopy. Phase content and chemical composition of the different phases present was determined by Energy-Dispersive Spectrometry and X-ray diffraction. Differential Scaling Calorimetry was used for analysis of thermal effects accompanied phase transformations in the course of solidification. On the basis of results obtained liquidus projection was constructed for Al-rich corner of the Al–Fe–U system. Two ternary peritectic reactions have been found to occur. It was proposed that 1) an orthorhombic phase UFe2Al10 is formed by ternary peritectic reaction: UAl3 + Al13Fe4 + Al(L) → UFe2Al10 within the temperature range of 850–1157 °C; 2) tetragonal phase U2FeAl20 is formed by ternary peritectic reaction: UAl4 + UFe2Al10 + Al(L) → U2FeAl20 at a temperature of about 639 °C.