Structural stability and mechanical property of Fe-W solid solutions from a constructed Fe-W potential

Abstract

An Fe-W potential has been constructed by means of the embedded-atom method and has proven to be more realistic than the three published Fe-W potentials in the literature. Based on the constructed Fe-W potential, molecular dynamic simulation has been used to reveal structural stability, thermodynamic properties, and mechanical properties of BCC Fe-W solid solutions within the entire composition range. It is found that the Fe-W interaction in BCC Fe-W solid solutions should be weak and attractive with small and negative heats of formation, which agree well with those from the thermodynamic Miedema model and could clarify the controversy regarding heats of formation of Fe-W solid solutions in the literature. In addition, the derived coefficient of thermal expansion, heat capacity, elastic constants, and elastic moduli of Fe-W solid solutions from the present Fe-W potential are in good agreement with the corresponding data from ab initio calculation or experiments in the literature.

Atomic structure, tensile property, and dislocation behavior of Fe–W interfaces from molecular dynamics simulation

“…Moreover, figures 1(c) and (d) display the periodic networks of misfit dislocations formed in the W(110)/Fe(110) and Fe(110)/W(110) interfaces, respectively. One can see from these two figures that the continuous vivid zigzags of green All the above agreements between the simulated and experimental atomic patterns of interface layers of Fe(110)/W(110) interfaces suggest that the recently constructed W-Fe EAM potential by the present authors [18] should be reliable to describe the interaction between W and Fe. Interestingly, a similar quasi-repeating pattern of the interface layers of the W(110)/Fe(110) interface has been predicted in figure 1(b) from the present MD simulation.…”

“…Obviously, the results derived by MD simulation and liner elasticity theory are close to each other. Such a good agreement means that the recently constructed Fe-W potential [18] is realistic to describe the dislocation behavior of the Fe-W system.…”

“…The present MD simulation is carried out by large-scale atomic/molecular massively parallel simulator package [17] with a recently published Fe-W EAM potential [18]. Two interface models are chosen in the present study, i.e., Fe(110)/W(110) and W(110)/Fe(110), in which the first and second parts correspond to the overlayer and substrate of the interface, respectively.…”

“…Before the analyses of the dislocation evolution of Fe-W interfaces, the relevance of the Fe-W potential [18] is tested in terms of dislocation energies. Based on the Fe-W potential [18], the energies of edge dislocations with the Burgers vector of 1/2 111 in bcc W and Fe lattices can be obtained through MD simulation:…”

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

“…experimental data [182,188], FP calculations [184], CALPHAD calculations [130,181,187,189], thermodynamic assessments [179,190] and MD calculations [130]. the bcc solid solution in the Fe-W system at 0 K. In comparison with DFT [193] and EAM calculations [198,199]. The reference states are bcc Fe and bcc W. elastic moduli for the bcc solid solution in the Fe-W system at 0 K. In comparison with experimental data [228], DFT [193] and EAM calculations [198,199].…”