45373 - Physics of Materials

Learning outcomes

At the end of the course, the student possesses the fundamental knowledges about the structure of ideal and real materials, the thermodynamics of multi-phase materials, the atomic-scale mechanisms that guide phase transformations and kinetic processes.

Course contents

1- Symmetry, structure and equilibrium properties
Physical properties and their tensor representation: intrinsic symmetry. Neumann's principle. Ideal crystalline state and symmetry operations. Stereographic projection. Euler's theorem and combination of symmetry axes. Crystallographic point groups and the symmetry of tensor properties. Applications: pyroelectricity, ferroelectricity, optical properties, piezoelectricity, elasticity. Neumann's principle in space-time. The space groups and their construction. Examples of various crystal structures. Topological close-packing. Long rane order without translational symmetry: quasicrystals.

2- Thermodynamics and Phase Transformations
Phase diagram of a pure substance: Clapeyron equation, vapor pressure. Phase diagram and free energy of a binary system: long-range order and miscibility gap versus temperature. Solid solutions: ideal, diluted and regular solutions. Short range ordering. Construction of binary phase diagrams: the common tangent method and the lever rule. Understanding basic features of phase diagrams: invariant points, liquidus, solidus, and solvus lines. Examples of phase diagrams.
Entropy and entropy production. Basic postulate of irreversible thermodynamics. The Onsager reciprocity relations. Atomic mechanisms for diffusion: thermally activated jumps. Vacancy, interstitialcy and interstitial mechanisms. Diffusion in ionic solids.
Phase transformations: continuous versus discontinuous. Spinodal decomposition and order-disorder transformations. The classical theory of nucleation. Nucleation and growth: Johnson-Mehl-Avrami kinetics and time-temperature- transformation (TTT) diagrams. Precipitation in the Cu-Co and Al-Cu systems. Martensitic transformation and shape-memory alloys.

3- Specific applications
Nanostructured materials
Extended defects in crystals: dislocations and interfaces
Mechanical properties of materials
Hydrogen storage in the solid state
Thermoelectric materials

Readings/Bibliography

· M. De Graef, M. E. McHenry, Structure of Materials, Cambridge University Press

· R.A. Swalin, Thermodynamics of Solids, Wiley

· R.W. Balluffi, S.M. Allen, W.C. Carter, Kinetics of Materials, Wiley

Teaching methods

Lectures

Assessment methods

Oral exam

Teaching tools

Personal computer and projector, dedicated software tools
Teaching material will be available on campus.unibo.it

Office hours

See the website of Luca Pasquini