Question 1: Phase Diagrams (10 points) The Cu-Zn (brass) phase diagram is given below. Use it to answer the following questions. (a) What are the melting temperatures of pure Cu and Zn? (1 point) (b) At what temperature will a 59.8 wt% Zn-40.2 wt%Cu alloy start to melt? (1 point) (c) At what compositions will an alloy undergo a + L + phase transformation? (1 point) For parts d-g, refer to the following alloys. Alloy 1 has an overall composition of 36.8 wt%Zn-63.2 wt%Cu and is held at 700C. Alloy 2 has an overall composition of 76.5 wt%Zn-23.5 wt%Cu and is held at 400C. (d) What phases are present in each alloy? (1 points) (e) What are the compositions of the phases in each alloy? (1 points) (f) What are the weight fractions of the phases in each alloy? (2 points) (g) What phase changes will occur if Alloy 1 is heated to 1000C and Alloy 2 is heated to 600C? (3 points) C 1100 1000 900 800 700 600 500 400 300 200 0 10 10 20 a 20 30 -902 30 40 454 40 at% Zn 50 B 834 B 460 50 wt% Zn 60 60 Y 70 Liquid 560 700 70 80 600 80 E 90 100 423 90 100