THERMODYNAMICS AND STRUCTURAL CONDITION OF PB-SB ALLOYS

Abstract

In this paper we study the structural condition and thermodynamic functions of a melt of the Pb-Sb. The investigations were performed for alloys with an antimony content of 5.0-20.0% (wt.), the rest is lead. To determine the structural condition of alloys we use microstructure analysis, differential thermal and X-ray structural analyses. The phase composition of alloys was determined in relation to the temperature of the liquid heating above the liquidus curve and to the cooling rate. With accounting for the first degree approximation of high-temperature expansion of the thermodynamic potential in expression for the Gibbs energy of a melt of the binary Pb-Sb alloy we find the curve of thermodynamic stability of the liquid depending on the antimony content in alloy. This approach enables to give the most complete description of the alloys’ melt from the thermodynamic point of view and to determine a thermodynamic stability curve, above which there are no microcomplexes in the phase. The results of the calculations obtained in this paper are in good agreement with the experimental data.

Keywords

• сплави Pb-Sb
• енергія Гіббса
• розплав
• термодинамічна стійкість