Solidification of Off-Eutectic Systems

When the eutectic temperature is reached, the remaining melt solidifies with lamellas of a and (3 phases so that the final solid will be composed of grains of primary a (sometimes called proeutectic a) interspersed in lamellas of eutectic a and p. The total mole fraction of 

Solidification of a hypereutectic system takes place in a similar manner except that primary P replaces the primary a that is interspersed throughout the eutectic matrix in the final solid. 

Solidification of a hypoeutectic melt described with a generic eutectic phase diagram. 

---