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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 Introduction Nomenclature Phase diagrams Invariant Reactions Eutectic Reaction Microstructure Morphology Model Specimen Lab report Equilibrium Diagrams Phase 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/Figure59.htm http://www.eng.auburn.edu/~wfgale/intro_metals/graphics/fig10_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: Eutectic L cooling cooling Eutecticoid Peritectic L Peritectoid Montectic cooling cooling L 1 L 2 cooling 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 lamellar rodlike globular acicular Invariant Reactions Eutectic Reaction Microstructure Morphology Model 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 Nomenclature Phase diagrams Invariant Reactions Eutectic Reaction Microstructure Morphology Model Specimen Lab report Required: 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-Cu3P) phase diagram. Lab Report (2) Due Date Introduction Nomenclature Phase diagrams Invariant Reactions Eutectic Reaction Microstructure Morphology Model Specimen Lab report Due to the 6th of October holiday, next week labs are cancelled. Lab report #2 is due in Tuesday October 8th class Questions?
