9B.1: You are trying to create a new alloy made of recently discovered elements Virginium (Vr) and Washingtonium (Dc). A fellow scientist created the phase diagram for the whole system and a TTT diagram for a system of 60% Vr, 40% Dc starting at 400 C, but needs help to answer the following questions. Temperature, C 1600- 15383 1475 1400- 1394 8 (Vr) 1200- 1000- 912 800- 600- 400- y+a 200- Vr L 250 a+ Y+B 690 & (Dc) 1230 1246 1155 1138 1100 n (De) 10 20 30 40 50 60 80 70 80 90 100 wt.% Dc Bo 727 400 300 T(C) Y (stable) 250 C Y 200 150 D a+ 50 0 680 100 B 100% 10 102 10 106 time (s) a) Write the letter of the point in the phase diagram next to the corresponding phase combination provided below that is present at that point. (15 pts) i. (beta phase) Point ii. y (gamma phase) Point iii. a (alpha phase) Point iv. a++y (eutectoid point) Point V. y+n (gamma and eta phases) Point b) Determine the composition and amount of each phase present in a 60% Dc alloy at 600 C. (20 pts) Phase Composition (% Dc) Amount (%phase) c) You heat the system and hold it at point B, then slowly cool it at constant composition to room temperature. Which of the following is present when the process is complete (circle the number of all that apply) (12 pts) HINT: Point B is directly above Point C. Pro-eutectoid y phase 1. 2. Pro-eutectoid a phase 3. Pro-eutectoid phase 4. Eutectoid y gamma phase 5. Eutectoid a phase 6. Eutectoid phase d) Use the phase diagram and/or TTT diagram for the 60% Vr, 40% Dc alloy to determine the following (8 pts): i. The steps required to process the alloy such that you end up with 50% retained y in the microstructure at 0 C. (Circle One) ii. Process A Process B Process C Process C What type of phase is present after reaching room temperature following Process A? (Circle One) Pro-eutectoid Hypereutectoid Precipitate Metastable