MT 250 Metallurgical Concepts (Fall 2003)

Study Guide for Physical Metallurgy

I give below a list of topics covered in class. You need to understand the concepts (which are also listed) under each topic. You show your understanding by being able to describe the concept, to use it in appropriate settings, to do simple calculations, etc. The level of questions will be roughly the same as that of the home assignments.

The final examination will be for one-and-a-half hours. In addition to a calculator, you can bring your books, notes, and anything else that might be of use.

Crystal structure

1. Lattices, symmetry elements
2. Simple cubic, body-centered cubic and face-centered cubic, hexagonal close-packed structures
3. Miller and Miller-Bravais index notation for planes and directions
4. Bragg's law; Structure determination using X-ray diffraction

Defects

1. Vacancies, equilibrium vacancy concentration and its temperature dependence
2. Dislocations: burgers vector, line direction, edge and screw dislocations, their energies
3. Dislocations in fcc metals: Shockley partials, stacking faults
4. Grain boundaries: small angle and large angle grain boundaries, tilt and twist boundaries, twin boundaries

Recovery, recrystallization, grain growth

1. Microscopic processes during recovery
2. Changes in microstructure during recovery, recrystallization and grain growth
3. Simple calculation of the stored energy due to plastic deformation
4. Effect of annealing temperature and annealing time on recrystallization (volume fraction of recrystallized grains)
5. Definition of recrystallization temperature
6. Hardness vs. annealing temperature for different annealing times
7. Resistivity vs. annealing temperature for different annealing times
8. Evolved heat energy vs. temperature in a continuous heating experiment
9. Dynamic recrystallization and hot working
10. Difference between cold and hot deformation
11. Driving force for grain growth
12. Effect of annealing temperature and annealing time on grain growth

Phase diagrams and phase transformations

1. Isomorphous systems: solidus, liquidus, tie-line, lever rule, solidification microstructures under near-equilibrium and non-equilibrium cooling, coring and segregation, temperature vs time plots (thermal analysis) for pure metals and alloys
2. Congruent melting
3. Eutectic systems: eutectic temperature and composition, solidification behaviour of, and microstructure development in, eutectic, hypo-eutectic and hyper-eutectic alloys; their thermal analysis curves
4. Peritectic systems: Peritectic temperature and composition, solidification of the peritectic alloy under near-equilibrium and non-equilibrium conditions; microstructure development
5. Gibbs phase rule: application to different parts of a phase diagram, identification and location of invariant points
6. Precipitation: phase diagram features, nucleation, growth and coarsening (Ostwald ripening), microstructure development, age-hardening behaviour and its rationalization in terms of microstructures, effect of temperature and composition on precipitation (volume fraction, average precipitate size and average inter-precipitate distance)

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