The binary phase diagram for the silver (Ag) and germanium (Ge) system is shown in Figure 11-34.

Figure 11-34 The silver-germanium phase diagram (for Problem 11-35).

(a) Schematically draw the phase diagram, and label the phases present in each region of the diagram. Denote α as the Ag-rich solid phase and β as the Ge-rich solid phase. Use L to denote the liquid phase.
(b) For an overall composition of 80% Ge (20% Ag) at a temperature of 700 K, what are the compositions and amounts of the phases present?
(c) What is the transformation in phases that occurs on solidification from the melt at the point marked with a circle? What is the special name given to this transformation?
(d) Draw a schematic diagram illustrating the final microstructure of 15% Ge (85% Ag) cooled to 300 K from the liquid state.

1300 1100 2 900 E 700 500 300 0 10 20 30 40 50 60 70 80 90 100 0% Ge 100% Ge 090 A Atomic 90 Ge 100% Ag