Thermodynamic characteristics of liquid metallic alloys containing lead, antimony and bismuth

Abstract

An improved construction of the electrochemical cell and optimized technique for measuring the electromotive forces (EMF) of liquid metallic Pb-Bi-Sb, Pb-Bi and Pb-Sb alloys in the KCl-PbCl2 melt are described in this paper. Proposed extensions allowed studying alloys of three different compositions simultaneously and increasing the reliability of the experimental EMF values. A simplified procedure for calculating integral molar thermodynamic functions of binary and ternary systems by the Darken method using only standard Excel tools is described in detail. Dependences of the integral excess Gibbs energy and entropy, integral molar Gibbs energy, mixing entropy and mixing enthalpy on the antimony mole fraction are calculated at 973 K for the Bi-Sb system, which cannot be studied by the EMF method due to the proximity of Bi and Sb potentials in the electrochemical series. The results confirm that the developed techniques are promising for determining thermodynamic characteristics of one of the binary systems without experimental study.