1. (25 pts. Using Figure 9.19 (below), answer the following questions: i. (2 pts) List each phase present at 600C and 40 wt% Zn. ii. (3 pts) Determine the composition of each phase present at 600C and 40 wt% Zn. iii. (8 pts) Determine the mass fractions of each phase present at 600C and 40 wt% Zn. iv. (2 pts) Determine the degrees of freedom present in the a+B region, and in the Bregion. Show your work (10 pts) Draw representative equilibrium microstructures for a composition of 40wt% Zn as it is cooled from 1200C at equilibrium. Your answer should include a one schematic from each in order: the liquid region, the B+L region, the B region, the a+B region, and the a+' region. Assume that the a phase will nucleate at Bphase grain boundaries. V. Composition at% Zn) 20 40 60 80 1200 100 2200 2000 +2 Liquid 1000 1 1800 B+ 1600 800 1400 B Temperature (C) Temperature (1) 5+L 1 1200 19+ 600 Y 8+ +1000 7 4 800 400 + 600 100 200 0 20 400 40 60 80 Composition (wt% Zn) Adapted from Binary Alloy Phase Diagrams, 2nd edition, Vol. 2.T.B. Massalski (Editor-in-Chief), 1990. Reprinted by permission of ASM International, Materials Park, OH (Zn) Cul