The Binary Eutectic

The Binary Eutectic
1- The reaction involving a liquid changing to two crystalline phases is called eutectic reaction.
2- In the figure below point E is the eutectic point at this point the reaction is L A crystal+ B crystal
3- The microscope were arranged to melt X at various stage of crystalline might appear as shown in the figure below.
Intermediate Component
1- Component composed of two or more component occur in the system referred to intermediate component.
2- In binary system these component are composed of various ratio of two component of the system.
3- The
4- The component AB2 divided the system into two eutectic binary system A-AB2 and B-AB2.
Congruent melting & Incongruent melting

- Congruent melting: occurs during melting of a compound when the composition of the liquid that forms is the same as the composition of the solid. This generally happens in two-component systems.
- To take a general case, let A and B be the two components and AB a stable solid compound formed by their chemical combination. In the phase diagram, we can notice that the top point D of the phase diagram is the congruent melting point of the compound AB because the solid and liquid phases now have the same composition.
- Congruent melting point represents a definite temperature just like the melting points of pure components. In the phase diagram, the congruent melting point D of compound AB lies above the melting points of pure components A and B.

component AB2 in the figure below formed of the component A and B.