Non-Equilibrium and Near-Equilibrium Solidification of Undercooled Melts of Ni- and Al-based Alloys

Abstract

Atomization and levitation are applied to undercool metallic melts and alloys prior to solidification. Heterogeneous nucleation on crucible walls is completely avoided giving access to large undercoolings. An undercooled melt possesses an enhanced free energy so that it can select different pathways to metastable solids. In this work dendrite growth and microstructure formation are investigated during solidification of undercooled melts of Ni- and Al-based alloys with respect to non-equilibrium solidification during recalescence and near equilibrium solidification during post-recalescence period