Question $3)$ The Bismuth $($Bi$)-$ Lead $($Pb$)$ phase diagram is given below;

a$)$ What are the elements of the phases $($phase contents$)$ formed at point $"$a$"?$ What are the ratios of the phases formed relative to each other?

b$)$ What are the elements of the phases $($phase contents$)$ formed at point $"$b$"?$ What are the ratios of the phases formed relative to each other?

c$)$ Draw the shape of the grains formed at point $"\backslash ($ b $\backslash )".$ What phases constitute the grains? What are the proportions of each grain type formed at this stage?

d$)$ What is the maximum solubility of Bi inside $\backslash (\backslash$beta $\backslash )$ and $\backslash (\backslash$gamma $\backslash )$ phases? Also write the temperatures of the $\backslash (\backslash$beta $\backslash )$ and $\backslash (\backslash$gamma $\backslash )$ phases where the maximum solubility of Bi element is seen.