Non-Equilibrium Solidification of Undercooled Metallic Melts

Abstract The non-equilibrium state of an undercooled melt allows the investigation of various phenomena involved in the formation of metastable solid phase. The present work reviews the present state of the art in this field. In detail, the thermodynamics of the undercooled melt, nucleation and growth processes are discussed, with special emphasis on the conditions of the formation of metastable states, such as metastable crystalline metals, quasi-crystals, metallic glasses, supersaturated solutions and grain-refined materials. The techniques needed for the in-situ investigation of non-equilibrium solidification phenomena in undercooled melts are discussed, and their potential for such investigations is evaluated. Aspects of microgravity research in this field are also included.