Solidification of the eutectic Sn–43 mol % Bi alloy

The processes of melting and solidification of the eutectic Sn–43 mol % Bi alloy are studied by cyclic thermal analysis. It is found that this alloy melts at a temperature TL = 412 K (which corresponds to the reference melting temperature of the eutectic) upon heating and solidifies isothermally at a temperature TS = 394 K upon cooling; that is, the temperature difference is ΔTLS −= 18 K. A comparison of temperatures TL and TS reveals a temperature hysteresis (TH). The activities and the activity coefficients of tin and bismuth in the eutectic are calculated at temperatures TL and TS. The enthalpies of melting at TL and solidification at TS are measured. The ways of changing the Gibbs energy during TH are determined. © 2017, Pleiades Publishing, Ltd.