Syllabus
1. Diffusion processes: Definition of diffusion, types and mechanisms of diffusion. Atomic theory of diffusion (crystal lattice vibration, random jumps and atomic mean square displacement, interstitial diffusion, derivation of I. Fick’s law, vacancy mechanism of diffusion, temperature dependence of diffusion rate). Phenomenological theory of diffusion (Fick’s laws, Fick’s experiments, solution of diffusion equations). Increase of diffusion rate due to point defects. Interdiffusion – Kirkendall effect.
2. Static recovery (point defects, dislocation substructure) and recrystallization: Methods of thermomechanical treatment of metals. Softening of metals during isothermal ageing. Stages of point defect recovery. Recovery of dislocation substructure, polygonization. Investigation methods of recovery (electric resistance measurement, DSC). Static recrystallization (nucleation and growth of new grains, effect of alloying elements and secondary phases, kinetics of recrystallization – Avrami equation). Secondary recrystallization (conditions, impact on mechanical properties). Computer simulation, microscale models (Monte Carlo, cellular models, Avrami models), macroscale models.
3. Dynamic recovery and recrystallization: Comparison with static processes. Characteristic deformation curves, dependence on deformation and recrystallization rates. Definition of Zener-Hollomon parameter. Microstructure evolution during dynamic recrystallization. Nucleation by bulging mechanism. Model of grain boundary motion. Computer models.
4. Creep of metallic materials: Mechanisms of creep. Creep test. Stages of creep curve (transient, steady-state, tertiary creep). Constitutive equations of creep. Model of diffusion creep (Nabarro-Herring, Coble). Model of dislocation creep. Creep fracture. Increasing creep resistance.
5. Fatigue and fracture: Concept of fatigue. Fatigue damage. Fatigue testing, factors influencing fatigue life. Fatigue crack initiation and growth. Fracture (mechanisms of ductile and brittle failure, fracture mechanics).
6. Corrosion damage: Chemical corrosion of metals, Pilling-Bedworth rule, thermodynamics and kinetics of electrochemical corrosion, immunity, activity, passivity, selected forms of corrosion, pitting and crevice corrosion, intercrystalline corrosion, corrosion cracking.
7. Radiation damage and hardening after irradiation. Radiation types. Interaction of radiation with matter. Collision cascades. Damage zone. Cross sections of atoms (alloying elements). Radiation effects on materials. Mechanical properties of irradiated materials (influence on yield point, ductility, creep and fatigue properties). Effect of temperature during irradiation.
Annotation
Thermally activated processes. Diffusion.
Recovery of point defects and dislocation substructure. Polygonisation, dynamic recovery, static and dynamic recrystallisation.
Creep. Corrosion.
Radiation demage and hardening after irradiation.