This document discusses key concepts in phase diagrams including unary and binary phase diagrams. It defines important terms like system, phase, and phase equilibrium. It explains that unary phase diagrams show the relationship between a single component and variables like pressure and temperature. Binary phase diagrams illustrate the relationship between two components, temperature, and composition, and can reveal properties like complete solubility, partial solubility, and eutectic points. Gibbs' phase rule is also summarized, which relates the number of phases, components, and degrees of freedom in a system.

2. PHASE
DIAGRAMS
By:
Ahmad Reza Gharibi
Materials properties
2

3. Presentation index
Some basic concepts & applications
Unary phase diagram
Cooling curves
Gibbs' phase rule
(Eutectic) binary phase diagram & lever rule

4. Some basic concepts
• System
• Phase
• Phase equilibrium
• Phase diagram (equilibrium diagram)
• Alloy
• Solubility of solids

5. Unary phase diagram
just one component (pure)
P
Unary phase determinants V
T
 Common variables: P-T

7. Cooling curves

8. Gibbs’ Phase Rule
P + F = C + 2
F : degrees of Freedom
C : number of Components P + F = C +1
P : number of Phases For binary systems

9. Binary phase diagram
Common variables : P - T - C (composition)
P or T = Cte
Complete solubility
Binary system : Partial solubility
Insolubility have eutectic point

12. Phase diagram for partially solid solution

13.  Determination of
composition and
weight fractions
using lever law in
two-phase regions