Give the schematic representation of the equilibrium microstructures for a lead-tin alloy of composition 45 wt% of tin at temperatures of 250oC, 200oC and 150oC. And please give the composition of alpha phase, beta phase at 183oC. Calculate the weight percentage of primary alpha phase and total alpha phase at temperature slightly below 183oC. Compare the melting temperature of 50 wt% Cu- 50wt% Ni alloys formed by equilibrium and nonequillibirum solidification, and explain why