Enthalpies of formation and lattice parameters of B2 phases in Al-Ni-X systems

Abstract

Enthalpies of formation of Al-Ni-X (X: Fe, Ru, Pd, Pt, and Cu) alloys were measured by high-temperature calorimeter and compared with the calculated value from Miedema's model and interpolation models. The interpolation models generally provide better prediction than Miedama's model. No one interpolation model generated superior predictions. Lattice parameters of B2 phase compounds were determined by X-ray diffraction (XRD). The atomic volumes in the Al-Ni-Fe system were calculated and show that Fe substitutes preferentially on the Al sublattice. The heat content of Al0.5Ni0.2Ru0.3 and Al0.5Ni0.35Cu0.15 at high temperature was obtained, and the results are in good agreement with those heat capacities estimated by the Neumann-Kopp rule. © 2007 IUPAC.