Effects of Melt Cyclical Superheating Conditions on the Microstructure of FeSi₂ Alloy

Abstract

In order to avoid coarse primary-precipitated ε phase which prolong α+ε→β phase transition time in FeSi2 material prepared by conventional casting, a cyclical superheating process of melt for preparing FeSi2 with complete α+ε eutectic structure was proposed. The effects of melt superheating conditions on the microstructure of FeSi2 were investigated. The results showed that, with the increase of the superheating temperature, the superheating time, the recycling times and the cooling velocity, the size and quantity of the ε phase reduced. Meanwhile, the number of the fine eutectic structure increased. FeSi2 sample with uniform and complete α+ε eutectic structure was successfully prepared in the conditions of melt superheating temperature at 1550°C, superheating time for 10mins, recycling 3 times,melt cooling rate of 30°C/s.