Phase stability and mechanical property of W–Cu solid solutions from a newly derived W–Cu potential

Abstract

A new W–Cu potential has been established within the framework of the embedded-atom method (EAM) through the additional fitting of the structural energy differences between FCC and BCC structures of W and Cu. Based on this new potential, molecular dynamics simulations reveals that the lattice parameters of both BCC and FCC W–Cu solid solutions are bigger than those from the Vegard's law, and BCC and FCC W100-xCux solid solutions are thermodynamically more stable when 0 ≤ x ≤ 80 and 80 < x ≤ 100, respectively. Simulations also indicate that the solution of Cu in W would considerably decrease tensile strength and ductility of BCC W and a similar result could be obtained for the solution of W in FCC Cu. Furthermore, the derived lattice parameters, phase stability, heat capacity, and mechanical properties of W100-xCux solid solutions from the new potential are in accordance with other results from experiments, density functional calculation, and thermodynamic model in the literature.