The document discusses cooling curves and phase diagrams. It describes cooling curves for pure metals and binary systems, showing temperature remaining constant as latent heat is released during solidification. It also outlines different types of phase diagrams for binary alloy systems with complete or partial solid solubility. Key phase reactions discussed include eutectic, peritectic, eutectoid, and peritectoid reactions.

1. COOLING CURVE
Unit -1

2. Cooling curve
• The solidification of molten metal is plotted as
a graph is called cooling curve.
• X – axis – Time
• Y – axis -Temperature

3. Types of cooling curve
1. Cooling curve for Pure metal or compound
(liquid , solid)
2. Cooling curve of a binary solution (liquid,
solid ,liquid + solid)
3. Cooling curve of a binary Eutectic system
(liquid, solid ,liquid + solid)

4. .

5. 1.Cooling curve for Pure metal or
compound
PQ -- Molten Metal Looses Its Temp
Q – Starting Point For Crystal Structure
QR –Latent heat is liberated Temp remains constant
RS – Solid metal formation

6. CONSTRUCTION OF PHASE DIAGEAMS

7. TYPES OF EQUILIBRIUM PHASE
DIAGRAM
1. Phase diagrams for complete solid solubility
(Phase diagrams for binary isomorphous alloy
systems)
2. Phase diagrams for partial solid solubility
(Phase diagrams for binary eutectic alloy
systems)

10. PHASE REACTIONS
• Eutectic reaction
• Peritectic reaction
• Eutectoid reaction
• Peritectoid reaction

11. Eutectic reaction

13. Peritectic reaction

15. Eutectoid reaction

17. Peritectoid reaction