Use the Pb-Sn phase diagram to answer problem 8 to 11 Composition at Sni 0 20 40 60 80 327 100 600 300 Liquid 500 232"c .. 200 183'C 400 Temperature (C) Temperature (F) 18.3 61.9 97.8 300 100 200 100 40 100 (Sn) (Pb) Composition (wtkSn) 8) A lead-tin (Pb-Sn) alloy composed of 60 wt% Pb is slowly cooled from 300 C to 100 C a. At what temperature does the first solid phase form? What is the composition (wt% Sn) of the solid phase at temperature slightly lower? b. Approximately what temperature does complete solidification of the alloy occur? c. What is the composition of the last liquid remaining slightly prior to complete solidification? 9) Draw the microstructures of Pb-Sn Alloy 1 (40 wt% Sn) and Alloy 2 (61.9 wt% Sn) that we can observe at room temperature if both alloys were cooled in equilibrium state. Alloy 1 Alloy 2