Thermodynamic properties of Al-Mn melts

The thermochemical properties of Al-Mn melts have been studied at 1835 ± 3 K by high-temperature calorimetry under isoperibolic conditions. The Δ_mix H and Δ_mix \(\overline H _i\), data obtained correlate well with earlier data obtained at a lower temperature of 1628 K. The enthalpies of formation of manganese aluminides determined by calorimetry agree only qualitatively with the Δ_mix H of Al-Mn melts. We have calculated the partial and integral entropies of mixing of Al-Mn melts. Analysis of the entire set of thermodynamic properties indicates that, in liquid Al-Mn alloys, the interaction between dissimilar atoms is significant even well above the liquidus temperature.