Containerless undercooling of bulk Fe-Ni melts

Abstract

Bulk samples of Fe1-xNix, with x covering the whole concentration range 0≤x≤1, have been undercooled in a containerless state by electromagnetic levitation, yielding undercooling levels not achieved to date by any other technique. Comparison with a theoretical approximation indicates that, despite the large undercoolings attained, the limit of homogeneous nucleation is not yet reached. The solidification of the undercooled melts is initiated rather by heterogeneous surface nucleation originating from surface oxidation processes.