Study of Dynamic Solid-Liquid Interfacial Phenomena in Hypereutectic Al-Si Alloy Using in situ HRTEM

Solid-liquid interfaces are extensively encountered in materials processing and applications. The structure and properties of these interfaces affect solidification, wetting behavior, and crystalline growth mechanisms, including epitaxial growth. The exact structural and chemical nature of these interfaces has been historically difficult to study at high resolution due to the fact that one phase is a liquid. Recently, in situ HRTEM experimental methods have progressed to enable the study of solid-liquid interfaces in metals with resolution on the atomic-scale [14]. Reported results thus far include direct observation of step/ledge growth [1], various crystallographic facets present during growth/dissolution[1,2], ordering of liquid layers adjacent to crystalline solids [14], and chemical segregation at interfaces [2,5]. This work reports first observations of new interfacial phenomena associated with the dynamic behavior of a highindex solid-liquid facet at equilibrium.