In-situ observations of solidification process of Fe–Al–Ta eutectic alloy

Abstract

The Fe–Al–Ta eutectic alloy can be formed by eutectic reaction in order to improve the performance of Fe–Al intermetallic compounds, and thus it is important to further clarify the crystal growth mechanism of the Fe–Al–Ta eutectic alloy during solidification. Thus, the melting and solidification temperatures of the Fe–Al–Ta eutectic alloy were determined by differential scanning calorimetry, and the melting and solidification processes of the Fe–Al–Ta eutectic alloy were observed in situ by high-temperature confocal scanning laser microscopy. In addition, the solidified structure of the Fe–Al–Ta eutectic alloy was observed and characterized by scanning electron microscopy and energy dispersive spectroscopy. No other types of phase transitions were found in the Fe–Al–Ta eutectic alloy when the temperature was below 1600 °C. The reinforced phase exhibited a certain orientation after solidification, and the microstructure at the center of the eutectic cell was much more regular than that at the grain boundary. The effect of the cooling rate on the microstructure morphology and the formation mechanism of the irregular divorced eutectic were analyzed.