Thermodynamic assessments of the Ni-Pt and Al-Ni-Pt systems

The Ni-Pt system is assessed using the CALPHAD method. The four fcc-based phases, i.e. disordered solid solution phase, Ni(3)Pt-L1(2), NiPt-L1(0) and NiPt(3)-L1(2), are described by a four-sublattice model. The calculated thermodynamic properties and order/disorder phase transformations are in good agreement with the experimental data. In order to facilitate the assessment, first-principles pseudopotential calculations are also performed to calculate the enthalpy of formation at 0 K, and comparison with the assessed values is discussed. By combining the assessments of Al-Ni and Al-Pt, the Al-Ni-Pt ternary system is assessed within a narrow temperature range, focusing on the fcc-based phases and their phase equilibria with B2 phase. (C) 2009 Elsevier Ltd. All rights reserved.