6. (10pts) Use the following magnified area of a Cu-Ni system phase diagram to answer questions. T(C) 1300 L (liquid) L+a 1200 Lta (solid) S 20 30 40 50 wt% Ni a) Based on the phase diagram above, what is the highest temperature a 50 wt% Ni alloy can be heated to WITHOUT any liquid phase starting to be present? b) For a 40 wt% Ni alloy, in what temperature range can both solid and liquid phase co-exist? C) For the same Ni composition, what are the volume fractions of solid and liquid at 1250 degrees C