Thermodynamic assessment of the miscibility gaps and the metastable liquidi in the Zn-Bi, Zn-Pb, and Zn-Tl systems

Abstract

In monotectic systems, there are thermodynamic restrictions on compositions and temperatures below the monotectic where the equilibrium solid cannot form directly from the undercooled homogeneous liquid. In this region, the solid can form only after liquid - liquid phase separation has occurred. As suggested by earlier research, the thermodynamic restrictions on the solidification process may be useful to control the microstructure of rapidly solidified materials. Thus, it could be commercially important to understand the thermodynamic limitations on the formation of the solid in monotectic systems. The liquid miscibility gaps, metastable liquidi, and spinodal curves in the binary Zn- Bi, Zn-Pb, and Zn-Tl systems were assessed by using a subregular solution model to describe the Gibbs energies of the liquid phases. The present results were compared and discussed with other experimental and assessed data available in the literature.