Composition = 0 wt% Pb Composition = 0 at% Pb Temperature = 0 C Composition (at% Pb) Temperature = 32 C 5 10 20 30 40 70 100 700 L 1200 600 L + Mg2Pb M a+L 1000 500 800 400 Temperature (C) L + Mg2Pb B + L 300 600 200 B 400 a + Mg2Pb 100 B+ MgoPb 200 Mg2Pb 0 100 (Mg) Composition (wt% Pb) (Pb) For a 76 wt% Pb-24 wt% Mg alloy, select the schematic sketch of the microstructure that would be observed at 450C for conditions of very slow cooling. The magnesium-lead phase diagram is shown in the Animated Figure 10.20. L (76 wt% Pb) a - (17 wt% Pb) Mg, Pb (81 wt%Pb) Mg, Pb (81 wt% Pb) (40 wt% Pb) 2 (71 wt% Pb) Mg, Pb (81 wi% Pb) L (71 wt% Pb) (81 wt% Pb)