The density of alloys of tin–lead system in the solid and liquid states

The method of gamma-raying the samples by a narrow beam of gamma radiation for cesium-$137$ isotope is used to investigate the density of five liquid alloys of a tin–lead system ($17.64$, $25.35$, $25.61$, $26.07$, and $33.88$ at.$\%\mathrm{Pb}$) in the temperature range from $293$ to $1040$ K with an error of $0.20$–$0.25\%$. Approximation dependences are obtained for the density of melts of investigated alloys, and our data are compared with the results of other authors. Procedural aspects of the investigation of the density of binary and multicomponent melts are treated, which are associated with the emergence of gradients of concentration of the components in the gravity field. Tables are compiled of the temperature dependences of the thermal properties of pure tin and lead from zero to $1600$–$1950$ K. It is demonstrated that the density of the solid and liquid phases of tin–lead system in the investigated concentration range may be calculated in an additive approximation with an error of $0.1$–$0.3\%$ or less.