Thermodynamic Optimisation of the Ni-Al-Y Ternary System

Ni-base superalloys become more attractive recently for its use in aerospace. As one of the most important constitutional ternary system the Ni-Al-Y system has been thermodynamically optimised in the present work. Solubility of yttrium in fcc-nickel and fcc-aluminium has been taken into account since yttrium can be used as an alloy element in Ni-base superalloys. A comprehensive set of thermodynamic parameters have been obtained. Calculated phase equilibria and enthalpies of formation of ternary intermetallic compounds are consistent with experimental data. This work can be used as basis of multi-component thermodynamic database for Ni-base alloys.