Anomalous dendrite growth in undercooled melts of Al–Ni alloys in relation to results obtained in reduced gravity

Abstract

Dendrite growth velocities are measured as a function of undercooling on Al–Ni alloys using electromagnetic levitation, both on Earth and in reduced gravity. Six alloys of various compositions are investigated, one of them for comparative investigations in reduced gravity. Whereas on the Ni-rich side, growth velocity increases with increasing undercooling, Al-rich alloys show an unusual decrease in growth velocity with increasing undercooling. Experiments in reduced gravity suggest that this anomalous behavior is caused by forced convection.