The equilibrated grain boundary groove shapes of solid solution Ag 2Al in equilibrium with an Al - Cu - Ag liquid were observed from a quenched sample with a radial heat flow apparatus. The Gibbs-Thomson coefficient, solid - liquid interfacial energy and grain boundary energy of the solid solution Ag2Al have been determined from the observed grain boundary groove shapes. The thermal conductivity of the solid phase and the thermal conductivity ratio of the liquid phase to solid phase for Ag 2Al - 28.3 at the % CuAl2 alloy at the melting temperature have also been measured with a radial heat flow apparatus and Bridgman type growth apparatus, separately. © 2009 Chin. Phys. Soc. and IOP Publishing Ltd.