For the lead-tin system: (a) Determine the proportions of liquid and solid phases for the 40% Sn composition of

the lead-tin system at temperatures 2500, 2000, 1500. (15 pts) (b) Draw the development of microstructure along the dashed line at points A,B,C, and D

Composition (at% Sn) 0 20 40 60 80 100 327C 600 300 A 1 Liquid 500 232C +L I 1 200 B 183C B + 400 B Temperature (C) Temperature (F) 18.3 61.9 97.8 300 I 1 1 I 1 100 +B 1200 100 0 20 40 60 80 100 (Pb) Composition (wt% Sn) (Sn)