Subject: Materials Engineering/Chemical Engineering (2018)

a) 500g of an alloy of 20 percent Pb and 80 percent Sn is slowly cooled down from 250C. By referring to the lead-tin phase diagram in Figure 2, answer the following: i) How many grams of liquid Pb and liquid Sn are present at 250C ? (2 Marks) ii) How many grams of liquid and pro-eutectic beta () are present at 200C ? (5 Marks) iii) How many grams of liquid and pro-eutectic beta () are present at 183C+T ? iv) How many grams of alpha () and beta () are present in the eutectic structure at 183CT? (5 Marks) Composition (at\% Sn) Figure 2