Interfacial energy of solid In2Bi intermetallic phase in equilibrium with In-Bi eutectic liquid at 72 degrees C equilibrating temperature

Abstract

A radial temperature gradient on the sample was established by heating from centre with a single heating wire and cooling the outside of sample at -10 degrees C with a heating/refrigerating circulating bath containing an aqueous ethylene glycol solution. The equilibrated grain boundary groove shapes of solid In2Bi (In-33.2 at.% Bi) in equilibrium with In-Bi eutectic liquid (In-22 at.% Bi) were observed from quenched sample at 72 degrees C. Gibbs-Thomson coefficient and solid-liquid interfacial energy of solid In2Bi in equilibrium with In-Bi eutectic liquid have been determined to be (11.3 +/- 0.6) x 10(-8) K m and (47.8 +/- 4.8) x 10(-3) J m(-2) from the observed grain boundary groove shapes. The grain boundary energy of solid In2Bi phase has been calculated to be (92.8 +/- 10.2) x 10(-3) J m(-2) by considering a force balance at the grain boundary grooves. The thermal conductivities of solid In solution (In-12.4 at.% Bi), solid In2Bi (In-33.2 at.% Bi), the eutectic liquid phase (In-22 at.% Bi) and their ratio at 72 degrees C have also been measured with radial heat flow apparatus and Bridgman type growth apparatus. (C) 2007 Elsevier Inc. All rights reserved.