Atomistic modeling of the γ and γ′-phases of the Ni-Al system

A new embedded-atom potential has been developed for Ni3Al by fitting to experimental and first-principles data. The potential describes lattice properties of Ni3Al, point defects, planar faults, Lis well as the gamma and gamma' fields on the Ni-Ad phase diagram. The potential is applied to calculate the energies of coherent Ni/Ni3Al interphase boundaries with three different crystallographic orientations. Depending on the orientation, the interface energy varies between 12 and 46 mJ/m(2). Coherent gamma/gamma' interfaces existing at high temperatures are shown to be more diffuse and are likely to have a lower energy than Ni/Ni3Al interfaces. (C) 2003 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.