Formation enthalpy of intermetallic phases from Al–Fe system measured with solution calorimetric method

The solution calorimetric method was used for the determination of the formation enthalpy of Al2Fe and Al5Fe2 intermetallic phases. The phases were prepared in a very pure Ar atmosphere by melting the calculated amounts of Al and Fe in alumina crucibles. Their crystal structure was confirmed with the X-ray diffraction method. A very low amount of Al5Fe2 phase was found in the Al2Fe phase. The calorimetric experiments were carried out using an Al bath at temperature 1271 K. The formation enthalpies of the Al5Fe2 and Al2Fe phases obtained at room temperature were −30.5 and −27.8 kJ/mol of atoms, respectively.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Preparation of Al2Fe, and Al5Fe2 phases. ► X-ray analysis of Al2Fe and Al5Fe2 phases. ► Scanning electron microscopy analysis of Al2Fe and Al5Fe2 phases. ► Measurement of solution heat effects for Al2Fe and Al5Fe2 phases. ► Determination of formation enthalpy for Al2Fe and Al5Fe2 phases.