Question

2) From the Cu-Ag phase diagram, determine the melting temperature of pure Cu and pure Ag. Determine also the eutectic temperature. 3) There are two liquidus line on the phase diagram. Let us assume that you have measured several cooling curves of samples covering from 0-100 wt% Ag composition range. The data points (phase transition points) on both liquidus lines are determined as in the following table: Left liquidus line Right liquidus line Wt% Ag Temperature (°C) Wt% Ag Temperature (°C) 71.9 774.3 71.9 774.3 64.8 806.7 76.2 795.4 57.6 837.3 80.4 818.4 48.7 876.4 83.9 839.4 40.0 913.6 87.7 862.4 32.0 947.9 90.8 882.5 22.1 989.9 94.9 911.2 10.9 1038.5 100.0 955.3 0.0 1084.3 Draw the above data points in a figure and fit both liquidus lines by second order polynomial equations. If you have two unknown compositions, x and x+5 (wt% Ag) with measured temperatures of 900C and 879C, respectively, determine the unknown compositions following the steps from the discussion slides. Show your work by plotting the LSE as a function of composition in the range from 0 to 95 wt% Ag. Hand-drawn plots will not be accepted!

Answer 1

Melting point of pure copper is about 1090 degree celcius.

Composition (at% Ag) - 40 60 80 100 .. TTTTT2200 1200 2000 1000 Liquid 1800 a +L 1600 779°C 1400 Temperature (°C) Temperature (°F) E:- Eutectic Reaction Point 1000 800 600 400 20 100 40 60 Composition (wt% Ag) (Ag)

Melting point of pure Ag is about 950 degree celcius

Eutectic temperature is 779 degree celcius