The American University in Cairo Mechanical Engineering Department

The American University in Cairo Mechanical Engineering Department MENG 426: Metals, Alloys & Composites Interactive MENG 426 Lab Tutorials Experiment (3) Eutectic, Hyper- & Hypo- Alloys Prepared by Eng. Moataz M. Attallah Fall 2002

Outline Introduction Nomenclature Phase diagrams Invariant Reactions Eutectic Reaction Microstructure Morphology Model Specimen Lab report 1. 2. 3. 4. 5. 6. Introduction: Phase diagrams Alloy systems Invariant Reactions Eutectic Reaction Specimen Results

Introduction Nomenclature Phase diagrams Invariant Reactions Eutectic Reaction Microstructure Morphology Model Specimen Lab report ® Phase Equilibrium Diagrams Diagram: Graphical representation for the material (pure/mixture/binary alloy/tertiary alloy) within a temperature range at a range of compositions, showing the existing phases & any transformation reactions. • Equilibrium cooling: slow cooling that does not deform the structure.

Phase Diagrams A B C

Unary Phase Diagram Introduction Nomenclature Phase diagrams Invariant Reactions Eutectic Reaction Microstructure Morphology Model Specimen Lab report http: //mst-online. nsu. edu/mstonline/metals/Figure 59. htm http: //www. eng. auburn. edu/~wfgale/intro_metals/graphics/fig 10_pure_fe. swf

Binary Phase Diagrams Introduction Nomenclature Phase diagrams Invariant Reactions Eutectic Reaction Microstructure Morphology Model No Solubility Isomorphous Extensive Solubility Specimen Lab report Partial Solubility Partial SS

Isomorphous System Extensive Solid Solution Strengthening (SSS) Introduction Nomenclature Phase diagrams Invariant Reactions Eutectic Reaction Microstructure Morphology Model Specimen Lab report Liquidus Solidus

Polymorphous System Partial Solid Solution Strengthening (SSS) Introduction Nomenclature Phase diagrams Liquidus Invariant Reactions Eutectic Reaction Microstructure Morphology Model Specimen Solidus Solvus Lab report Terminal Solid Solution

SSS Parameters Introduction Nomenclature Phase diagrams Invariant Reactions Eutectic Reaction Microstructure Morphology Model Specimen Lab report ® Difference in atomic radii less than 15% ® Same crystal structure ® Minimal difference in electronegativity ® Same valence number

Interstitial Solid Solution Introduction Nomenclature Phase diagrams Invariant Reactions Eutectic Reaction Microstructure Morphology Model Specimen Lab report

ISS Parameters Introduction Nomenclature Phase diagrams Invariant Reactions Eutectic Reaction Microstructure Morphology Model Specimen Lab report ® Existence of interstitial site that can accommodate a small atom ® Interstitials are: H, C, N, O

Invariant Reactions

Invariant Reactions Introduction Nomenclature Phase diagrams Invariant Reactions Eutectic Reaction Microstructure Morphology Model Specimen Lab report ® Phase transformation reactions that take place at a specific temperature and composition (zero degree of freedom). ® Types: Eutecticoid Peritectic Peritectoid Montectic

Eutectic Reaction Introduction Nomenclature Phase diagrams Invariant Reactions Eutectic Reaction Microstructure Morphology Model Specimen Lab report

Eutectic Microstructure Introduction Nomenclature Phase diagrams Invariant Reactions Eutectic Reaction Microstructure Morphology Model Specimen Lab report

Eutectic Morphologies* * Morphology means the form, shape or outward microstructure of a phase Introduction Nomenclature Phase diagrams Invariant Reactions Eutectic Reaction Microstructure Morphology Model lamellar rodlike globular acicular Specimen Lab report W. F. Smith

Eutectic Model Introduction Nomenclature Phase diagrams Invariant Reactions Eutectic Reaction Microstructure Morphology Model Specimen Lab report

Specimens Introduction Nomenclature Phase diagrams Invariant Reactions Eutectic Reaction Microstructure Morphology Model Specimen Lab report • Specimen (1): 8. 4% phosphorus content: etch or 30 seconds in aqueous ferrous chloride. • Specimen (2): 4. 5% phosphorus content: etch or 40 seconds in aqueous ferrous chloride, which makes a dark surface after etching. • Specimen (3): 10. 5% phosphorus content: etch for several seconds in a solution containing 2 parts of water/1 part ammonia solution and hydrogen peroxide.

Cu-P Phase Diagram Introduction Nomenclature Phase diagrams Invariant Reactions Eutectic Reaction Microstructure Morphology Model Specimen Lab report

Cu-P Phase transformation Introduction Nomenclature Phase diagrams Invariant Reactions Eutectic Reaction Microstructure Morphology Model Specimen Lab report

Lab Report Introduction Required: Nomenclature Phase diagrams ® Invariant Reactions Eutectic Reaction Microstructure Morphology Model Specimen Lab report A "neat" sketch for the viewed microstructures. ® Describe the phase transformation for each specimen from the liquid state to the solid state with the aid of the (Cu-Cu 3 P) phase diagram.

Lab Report (2) Due Date Introduction Nomenclature Phase diagrams Invariant Reactions Eutectic Reaction Microstructure Morphology Model Specimen Lab report Due to the 6 th of October holiday, next week labs are cancelled. Lab report #2 is due in Tuesday October 8 th class

Questions?