A correlation of the thermodynamic properties and phase diagram of the system lead-silver using a gaussian plus subregular formalism

Abstract

A method of correlating with precision the thermodynamic properties and phase boundaries of the lead-silver system is described. This employs a Gaussian plus subregular formalism for the liquid phase and uses Henrian behavior for the solid phases, which have minor extents of solid solubility. The experimental liquidus data obtained by using the high shear technique of Esdaile and Siviour1 are tabulated and also compared with the requirements of the phase diagram, leading to a mean temperature difference of 0.43 K for the silver-rich side and 0.017 K for the lead-rich side, between measured and calculated liquidus and solidus data. For the high temperature liquidus data of Heycock and Neville2 the mean temperature difference is 2.2 K. The calculated compositions of the solid lead and silver phases below the eutectic point are also compared with the experimental measurements. The lead-rich solidus boundary given by Hansen and Anderko3 is shown to be erroneous.