Mixing the immiscible through high-velocity mechanical impacts: an experimental and theoretical study

In two-component metallic systems, thermodynamic immiscibility leads to phase separation such as in two-phase eutectic compositional alloys. The limit of the immiscibility of component elements under non-equilibrium conditions have been explored, but achieving complete miscibility and formation of single phase microstructures in eutectic alloys would be unprecedented. Here, we report that during the low-temperature ball milling that provides high energy impact, complete mixing of phases can occur in immiscible Ag–Cu eutectic alloys. From combined theoretical and experimental studies, we show that impact can produce solid solutions of Ag–Cu nanoparticles of eutectic composition. Our results show that phase diagrams of low dimensional materials under non-equilibrium conditions remain unexplored and could lead to new alloy microstructures drastically different from their bulk counterparts.