Microstructure and interfacial tensions in Zn-In and Zn-Bi alloys

Solid/liquid and grain boundary interfacial tensions in Zn-In and Zn-Bi alloys have been measured as a function of temperature by the dihedral-angle method. The solid/liquid interfacial tensions increase as the zinc content in the liquid phase decreases. A relationship exists between solid/liquid interfacial tension and atomic interactions in the liquid phase, the latter being measured by excess thermodynamic quantities of mixing of bulk liquid alloys. The values of solid/liquid interfacial tension fit an equation derived from statistical thermodynamics which extrapolates to the solid/liquid interfacial tension of pure zinc. The observed morphologies of liquid inclusions in the solid zinc matrix are discussed in terms of solid/liquid dihedral angles on the basis of recent theories. © 1979 The Metals Society.