An Evaluation of Measurements of Solid/Liquid Interfacial Energies in Metallic Alloy Systems by the Groove Profile Method

摘要

Solid-liquid interfacial free energy sigma_(SL) plays a key role in a wide range of metallurgical phenomena. Pioneer estimates by Turnbull et al. in the 1950s from undercooling measurements were primarily for pure metals on the assumption of homogeneous nucleation and estimates from dihedral angle measurements require an independent measurement or estimate of sigma for at least one of the other interfaces involved. Gunduz and Hunt in 1985 reported the first direct measurements of sigma_(SL) for three eutectic alloy systems from the profiles of grain boundary grooves stabilized by a known radial temperature gradient, embodying a methodology applied prior to 1985 only to transparent systems or pure metals at or near to ambient temperatures. The significance of these and subsequent measurements and their application to solidification theory will be critically evaluated.