Composition dependence of solid-liquid interfacial energy of Fe-Cr binary alloy from molecular dynamics simulations

Composition dependence of the solid-liquid interfacial energy for Fe-Cr binary alloy is closely investigated by the molecular dynamics simulation in conjunction with the capillary fluctuation method. The solid-liquid interfacial energy of Fe-Cr alloy doesn't increase monotonically with increasing Cr composition but takes the minimum at approximately Fe-19.1at%Cr. Regarding the anisotropy effect, the interfacial energy of solid-liquid interface with (1 0 0) orientation is larger than those of (1 1 0) and (1 1 1) orientations at all compositions. Moreover, the effect of solute partition on the solid-liquid interfacial energy is discussed on the basis of a conceptual calculation using the solid-liquid biphasic system with various hypothetical compositions. The fluctuation of the interface becomes smooth at the solid-liquid interface with the small partition coefficient, which results in a large solid-liquid interfacial energy.