Subject: Materials Engineering/Chemical Engineering (2019)

(a) Answer the following questions by analysing the A-B binary phase diagram as shown in Figure 1: (i) What is the melting point of pure B? What will happen to this temperature if 20wt% of A is added to pure B ? (ii) What is ? (2 Marks) (1 Mark) (iii)What is the maximum solubility of B in ? At what temperature? (2 Marks) (b) If 650g of 70wt%B30wt%A alloy is slowly cooled from 1600C to just below the eutectic temperature: (i) What is the eutectic temperature and composition? (1 Mark) (ii) Determine the phases present, composition and amount of each phase present at 1600C,1000C and just below eutectic temperature. (13 Marks) (iii)Sketch and label the microstructure formed for each temperature in question (b) (ii). (3 Marks) Is this a binary isomorphous alloy? Justify your answer. (3 Marks) Figure 1: Binary Phase Diagram of A-B