Thermodynamic investigations in the Al-Fe system: Heat capacity measurements of three intermetallic phases

For a comprehensive understanding of the Al-Fe systems' thermodynamics further experimental investigations are required, especially for the Al-rich side. Intermetallic phases in the Al-Fe system have been produced by arc melting (stoichiometric compositions: Al2Fe, Al5Fe2 and Al13Fe4). The samples were heat treated at elevated temperatures and characterized using scanning electron microscopy, X-ray diffraction and inductive coupled plasma - optical emission spectrometry. Heat capacities were measured using independent heat flux differential scanning calorimeters in the temperature range from 223 K up to 1370 K. In general, the obtained data are lower than the estimations based on the Neumann-Kopp rule over a large temperature range. The heat capacity functions of the three intermetallic phases are represented by regression functions over the complete measured temperature intervals.