Single crystal elastic moduli of disordered cubic alloys Original Research Article

A computationally efficient, physics-based technique is described for calculating the composition dependence of single crystal elastic constants of disordered, single-phase alloys with face-centered cubic and body-centered cubic Bravais lattices. Alloys are modeled as virtual crystals in which the energy of representative atom pairs is approximated by a virtual potential constructed from the pair potentials of component pairs using a quasi-chemical approximation. Following the method of long waves, second-order elastic constants are calculated from first and second neighbor axisymmetric force constants obtained from the virtual potential. Since only elastic constants are modeled, the form of the potential employed contains only parameters that describe the slope and curvature in the vicinity of the first and second nearest neighbors. Examples are presented for several binary alloy systems differing in solubility characteristics and crystal structures of the pure solutes.