Enthalpy of Mixing in Al–Tb Liquid

Abstract

Abstract:The liquid-phase enthalpy of mixing for Al-Tb alloys is measured for 3, 5, 8, 10, and 20 at% Tb at selected temperatures in the range from 1364 to 1439 K. Methods include isothermal solution calorimetry and isoperibolic electromagnetic levitation drop calorimetry. Mixing enthalpy is determined relative to the unmixed pure (Al and Tb) components. The required formation enthalpy for the Al 3 Tb phase is computed from first-principles calculations. Based on our measurements, three different semi-empirical solution models are offered for the excess free energy of the liquid, including regular, subregular, and associate model formulations. These models are also compared with the Miedema model prediction of mixing enthalpy.

Thermodynamics in Material Science

“…This issue considers a number of highly relevant concerns which include: A study of the use of Boltzmann and Stirling approaches in theoretical nano-thermodynamic calculations [ 1 ] where the replacement of Stirling’s Approximation by the de Moivre approximation is shown to improve results. A study of Δ Η mixing of Al-Tb alloys in the liquid phase [ 2 ] A new procedure [ 3 ] is proposed for enhancing the performance of a microcooler in both homogeneous and hybrid systems. Composite Cu–Cr systems are examined during electric arc exposure [ 4 ].…”