Question

Neatly sketch to scale the Pb-Sn equilibrium diagram from the following data: Melting point of Pb = 327°C, Melting point of Sn = 232°C, Eutectic temperature = 183°C, Eutectic composition = 61.9 percent Sn, Maximum solubility of Sn in Pb at 183°C = 19.5 percent, Maximum solubility of Pb in Sn at 183°C = 2.6 percent Room temperature solubilities are negligible. From the above diagram, determine the following for an alloy containing 25 percent Sn (i) The freezing range and (ii) The relative proportions of phases at 192°​

Answer 1

Answer:

At the lead rich end of this binary alloy a large composition zone is associated with the a-phase. The maximum solid solubility of tin in lead occurs at the eutectic temperature (183 C) and the a-phase at this temperature has the composition Pb-19.2 wt % Sn.