The American University in CairoThe American University in CairoMechanical Engineering DepartmentMechanical Engineering Department

MENG 426: Metals, Alloys & CompositesMENG 426: Metals, Alloys & Composites

Interactive MENG 426 Lab TutorialsInteractive MENG 426 Lab Tutorials

Experiment (3)

Eutectic, Hyper- & Hypo- AlloysEutectic, Hyper- & Hypo- Alloys

Prepared byEng. Moataz M. AttallahEng. Moataz M. Attallah

Fall 2002Fall 2002

Introduction

Nomenclature

Phase diagrams

Invariant Reactions

Eutectic Reaction

Microstructure

Morphology

Model

Specimen

Lab report

OutlineOutline

1. Introduction: Phase diagrams

2. Alloy systems

3. Invariant Reactions

4. Eutectic Reaction

5. Specimen

6. Results

Introduction

Nomenclature

Phase diagrams

Invariant Reactions

Eutectic Reaction

Microstructure

Morphology

Model

Specimen

Lab report

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.

IntroductionIntroduction

Equilibrium Diagrams

• Equilibrium cooling: slow cooling that does not deform the structure.

Phase Diagrams A B CPhase Diagrams A B C

Introduction

Nomenclature

Phase diagrams

Invariant Reactions

Eutectic Reaction

Microstructure

Morphology

Model

Specimen

Lab report

Unary Phase DiagramUnary Phase Diagram

http://mst-online.nsu.edu/mstonline/metals/Figure59.htm

http://www.eng.auburn.edu/~wfgale/intro_metals/graphics/fig10_pure_fe.swf

Introduction

Nomenclature

Phase diagrams

Invariant Reactions

Eutectic Reaction

Microstructure

Morphology

Model

Specimen

Lab report

Binary Phase DiagramsBinary Phase Diagrams

No Solubility IsomorphousExtensive Solubility

Partial SolubilityPartial SS

Introduction

Nomenclature

Phase diagrams

Invariant Reactions

Eutectic Reaction

Microstructure

Morphology

Model

Specimen

Lab report

Isomorphous SystemIsomorphous SystemExtensive Solid Solution Strengthening (SSS)Extensive Solid Solution Strengthening (SSS)

Liquidus

Solidus

Introduction

Nomenclature

Phase diagrams

Invariant Reactions

Eutectic Reaction

Microstructure

Morphology

Model

Specimen

Lab report

Polymorphous SystemPolymorphous SystemPartial Solid Solution Strengthening (SSS)Partial Solid Solution Strengthening (SSS)

Liquidus

Solidus

Terminal Solid Solution

Solvus

Introduction

Nomenclature

Phase diagrams

Invariant Reactions

Eutectic Reaction

Microstructure

Morphology

Model

Specimen

Lab report

SSS ParametersSSS Parameters

Difference in atomic radii less than 15%

Same crystal structure Minimal difference in electro-

negativity Same valence number

Introduction

Nomenclature

Phase diagrams

Invariant Reactions

Eutectic Reaction

Microstructure

Morphology

Model

Specimen

Lab report

Interstitial Solid SolutionInterstitial Solid Solution

Introduction

Nomenclature

Phase diagrams

Invariant Reactions

Eutectic Reaction

Microstructure

Morphology

Model

Specimen

Lab report

ISS ParametersISS Parameters

Existence of interstitial site that can accommodate a small atom

Interstitials are: H, C, N, O

Invariant ReactionsInvariant Reactions

Introduction

Nomenclature

Phase diagrams

Invariant Reactions

Eutectic Reaction

Microstructure

Morphology

Model

Specimen

Lab report

Invariant ReactionsInvariant Reactions

Phase transformation reactions that take place at a specific temperature and composition (zero degree of freedom).

Types:Eutectic L

cooling

Eutecticoid cooling

Peritectic Lcooling

Peritectoid cooling

Montectic L Lcooling

1 2

Introduction

Nomenclature

Phase diagrams

Invariant Reactions

Eutectic Reaction

Microstructure

Morphology

Model

Specimen

Lab report

Eutectic ReactionEutectic Reaction

Introduction

Nomenclature

Phase diagrams

Invariant Reactions

Eutectic Reaction

Microstructure

Morphology

Model

Specimen

Lab report

Eutectic MicrostructureEutectic Microstructure

Introduction

Nomenclature

Phase diagrams

Invariant Reactions

Eutectic Reaction

Microstructure

Morphology

Model

Specimen

Lab report

Eutectic Morphologies*Eutectic Morphologies** * Morphology means the form, shape or outward microstructure of a phase

lamellarlamellar rodlike

globular acicular

W. F. Smith

Introduction

Nomenclature

Phase diagrams

Invariant Reactions

Eutectic Reaction

Microstructure

Morphology

Model

Specimen

Lab report

Eutectic ModelEutectic Model

Introduction

Nomenclature

Phase diagrams

Invariant Reactions

Eutectic Reaction

Microstructure

Morphology

Model

Specimen

Lab report

SpecimensSpecimens

•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.

Introduction

Nomenclature

Phase diagrams

Invariant Reactions

Eutectic Reaction

Microstructure

Morphology

Model

Specimen

Lab report

Cu-P Phase DiagramCu-P Phase Diagram

Introduction

Nomenclature

Phase diagrams

Invariant Reactions

Eutectic Reaction

Microstructure

Morphology

Model

Specimen

Lab report

Cu-P Phase transformationCu-P Phase transformation

Introduction

Nomenclature

Phase diagrams

Invariant Reactions

Eutectic Reaction

Microstructure

Morphology

Model

Specimen

Lab report

Lab ReportLab 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.

Introduction

Nomenclature

Phase diagrams

Invariant Reactions

Eutectic Reaction

Microstructure

Morphology

Model

Specimen

Lab report

Lab Report (2) Due DateLab Report (2) Due Date

Due to the 6th of October holiday, next week labs are cancelled.

Lab report #2 is due in

Tuesday October 8th class

Questions?Questions?