For a 25 wt% Pb-75 wt% Mg alloy, make schematic sketches of the microstructure that would be observed for conditions of very slow cooling at the following temperatures: 600C (1110F), 500C (930F), 400C (752F), and 200C (392F). Label all phases and indicate their approximate compositions and weight fraction. Temperature (C) 700 600 500 400 300 200 100 (Mg) 20 20 5 Composition (at% Pb) 10 a + L L a + Mg2Pb 40 60 Composition (wt% Pb) 20 30 40 70 100 L 1200 + Mg2Pb M 1000 800 L + B+L B Mg2Pb 600 400 B+ Mg2Pb 200 Mg2Pb 80 80 100 (Pb) Temperature (F)