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

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.