The In-Plane Structure and Dynamic Property of the Homogeneous Al-Al Solid-Liquid Interface

Abstract

Using molecular dynamics simulation and a newly developed COMB3 potential, the in-plane ordering and diffusion constant profiles at the homogeneous (100), (110), and (111) interfaces between solid and liquid Al have been examined. We found that the in-plane ordering characterized by 2-D density maps and 2-D structure factors existed in the first 6, 10, and 3 out-of-plane layers at the (100), (110), and (111) interfaces, respectively, showing a strong dependence on substrate orientation. In layers with in-plane ordering, the diffusion constant is greatly reduced relative to its value in the bulk liquid, while the influence of layers without in-plane ordering is negligible. The three diffusivity components turn out to be isotropic at the homogeneous interfaces. The Al-Al interfaces studied here will serve as an important reference in comparisons of the structure and properties of different solid-liquid interfaces, which will greatly support the design of grain refiners.