$($a$)$ A copper$-$silver alloy of composition $85wt\%Ag-15wt\%Cu$ is slowly heated from a temperature of $700C(1300F).$ Using Figure $1$ answer the following:

$($i$)$ At what temperature does the first liquid phase form?

$($ii$)$ What is the composition of this liquid phase?

$($iii$)$ At what temperature does complete melting of the alloy occur?

$($iv$)$ What is the composition of the last solid remaining prior to complete melting?

$($v$)$ Again using Figure $1$ draw the cooling curve and microstructures at various temperatures during solidification of a $95wt\%Ag-5wt\%Cu$ alloy.

$($b$)$ How does cored structure produce during non equilibrium cooling?