Abstract:Lead-lithium alloys are of great interest for practice as the advanced materials to be used in new technique, nuclear energetics, and so forth. Terefore, study on the physico-chemical properties of the latter is of major significance. An analysis of the available literature shows that there are a few works, devoted to study of Pb-Li alloys densities. However, temperature dependence of the density ρ(T), and its temperature coefficientK=dρ/dT for eutectic alloy were obtained by either extrapolation of the density data up to the eutectic alloy's composition, or calculation method. There is a certain discrepancy amounting to as high as 4，, while the allowable error in the density measurements is less than 0.5，. The discrepancy between the results for the temperature coefficients of density amounts to 80，.In this work we present the experimental data on the temperature dependence of Ph0.83 Li0.17 eutectic alloy's density in the temperature range 520K to 643 K. The alloys were prepared using Pb and Li with 99. 999， and 99.8， contents of the basic elements, respectively. We use the improved device, which permits to get the results with error less than 0. 15，. The results of 115 measurements of density in 520K to 643K temperature range were processed by the least-square method. Density polytherm of Pb0.83 Li0. 17 eutectic alloy is described by linear equation ρ(T) =9507.89-0. 79813(T-508) , kg/m3 ,where T is the absolute temperature by K. Mearsurement error was 0. 12， at 95， reliability.Discrepancy in the temperature coefficient data was 1.08，.Thus, the temperature dependence of the Pb-Li eutectic alloy density was studied by the precise two-capillary method. The obtained results may be recommended as the most reliable reference data.
