Construction of an n-body Fe–Cu potential and its application in atomistic modeling of Fe–Cu solid solutions

Abstract

By means of the embedded-atom method, a Fe–Cu potential has been constructed through a newly mathematic form of cross potential. The newly constructed Fe–Cu potential has demonstrated to be more reliable than the five reported Fe–Cu potentials. Based on the Fe–Cu potential, the mechanical and thermodynamic properties and the structural stability of Fe–Cu solid solutions in the whole composition range are derived by molecular dynamics simulation. It is found that the heat of formation curves of the FexCu100 − x solid solutions with body-centered-cubic (BCC) and face-centered-cubic (FCC) structures intersect at the point of x = 65, implying that FexCu100 − x solid solutions with FCC and BCC structures are thermodynamically stable when 0 ≤ x ≤ 65 and 65 < x ≤ 100, respectively. In addition, the derived lattice constants, structural stability, elastic constants, elastic moduli, heat capacity, and coefficients of thermal expansion of Fe–Cu solid solutions from the new Fe–Cu potential agree well with the data of the experiments, first-principles calculation, and the Miedema model.

Molecular dynamics study on the deformation and fracture of FeCo-based alloys

“…xx [160,167] and MD calculations [129,170]. experimental data [182,188], FP calculations [184], CALPHAD calculations [130,181,187,189], thermodynamic assessments [179,190] and MD calculations [130].…”

“…On the other hand, Lee et al [129] focused their study on the energetics of defects, but overlooked the assessment of the elastic moduli. [164,165,167,176] at ~298 K and CALPHAD assessments [160,167] and MD calculations [129,170].…”

“…Figure 6.3 (a) Atomic volume and (b) enthalpy of formation for the solid solution in the Fe-Cu system at 298 K. (c) Enthalpy of mixing for the bcc and fcc structures, and (d) elastic constants for the fcc solid solutions at 0 K. In comparison with experimental data[164,165,167,176] at ~298 K and CALPHAD assessments[160,167] and MD calculations[129,170].…”