1. Using the H2O-NaCl phase diagram,(a) What is the minimum temperature below which spreading salt on ice will be ineffective?(b) What concentration of salt is necessary to have a 25% ice- 75% liquid brine at 10 oC?
2. (a) Pure lead melts at 327oC and pure tin melts at 232o C, yet when we make an alloy of lead- 61.9 wt% Sn it melts at a much lower temperature of 183 oC, explain.
(b) Pure lead freezes at one constant temperature of 327 oC, yet the lead- 30 wt% Sn alloy freezes over a 60 oC temperature range, explain.
3. Draw schematic cooling curve for Cu- 20 wt% Ag alloy from 1100 oC to 200 oC.
(a) What phases are present at 780 oC and what are their compositions and weight fractions?
(b) What is the weight fraction of eutectic constituent in the microstructure at 775 oC?
(c) What phases are present at 600 oC and what are their compositions and weight fractions?
(d) What would be the weight fraction of precipitates in the phase at 600 oC in this alloy?