Department of Mechanics and Materials Science (2 pages)
 Examination Requirements of the course 
Properties and Processing of Materials in spring semestr 98/99
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1. Diffusion. Driving force of diffusion, definitions of concentration, interstitial and vacancy mechanisms of diffusion and the respective activation energies, frequency of atoms hopping, Fick's first and second lows, temperature dependence of diffusion coefficient, diffusion to a semi-infinite space, diffusion at the concentration discontinuity, diffusion from the surface source, diffusion in ionic materials and in polymers.
2. Solidification. Gibbs free energy and its temperature dependence for solid and liquid state. The change of enthalpy and entropy at the melting point. Derivation of critical radius of the nucleus. Rate of phase transformation. Planar and dendritic grows. Unidirectional crystallisation. Single crystal growth (Czochralski, floating zone, and Bridgmann-Stockbarger techniques). Cooling curves and phase diagrams. Phase equilibrium diagrams of carbon, Pb-Sn, Al-Si, Pb-Te, Fe-C.
3. Material conserving processes. Classification of Fe-C alloys. Quenching and annealing of steels. Zone refining. Casting techniques (permanent model, permanent old, continual casting, and rapid solidification technology), casting alloys based on Cu, Al, Fe, Pb, and Mg. Mechanical working techniques, cold and hot working, recrystallization.
4. Cutting and etching. Physical meaning of cutting, single point and multiply point techniques of cutting. Beam technologies (electron beam, laser, plasma, ion beam), ultrasound method, water jabbing method, particle stream erosion. Lithography, optical, x-ray, electron and without resist, ultimate limits of lithography. Electrochemical machining, electrical discharge machining.
5. Joining of materials. Methods of welding. Solid state welding, principles and examples, thermocompression. Oxyacetylene welding, solidification of the weld. Arc welding, the role of electrode coating. Welding in inert atmosphere. Advantages of the electron beam, laser or plasma welding. Aluminium welding. The operational steps in soldering, methods of heating, and the conditions for wetting. The sorts of solders. The roles of fluxing agent. Fluxing agents for general use and for electronics. Rules for different materials soldering. Classification of adhesives, conductive adhesives. Steps in powder technology, physical meaning of sintering, and the examples of sintered materials in electrotechnics. Composite materials classification, modification of properties of polymers, metals and ceramics in composite materials, high strength and high modulus fibbers, conductive composites, percolation threshold in carbon black composites. 
6. Layers. Definitions of thin and thick layers, definition of sheet resistance. Physical background of vapour phase deposition in relation to phase diagram, conditions for glass, polycrystalline and single crystal layer formation, conditions for epitaxial growth. Physical background of cathode sputtering, the examples of sputtering in inert and active gas. Typical reactions in chemical vapour deposition. Advantages of molecular beam epitaxy. Preconditions for liquid phase epitaxy. Technology of monomolecular Langmuir-Blodgett films and multilayers. Technological steps in screen-printing, tixotropic behaviour of the paste, composition of the paste for conductors, dielectrics and resistors.
7. Ageing of materials. Examples of chemical corrosion of metals and polymers. Effect of the oxide structure on kinetics of metal oxidation, corrosion of Cu and Fe in hydrogen atmosphere, physical background of thermooxidation of polymers. Physical background of electrochemical corrosion, electromotive force of metals, function of electrolyte, process of cathode depolarisation. Preconditions of electrochemical corrosion and classification of protection methods from corrosion. Cathodic and anodic protection layers, advantages and disadvantages. Passivating films. 
8. Contacts, conductors and capacitors. Technology of materials for metallurgical and mechanical joints. Contact materials in electronics, requirements and common alloys. Insulating layers on the contacts. Through hole and surface mount technology of printed circuit boards, advantages and disadvantages, used materials of boards, approach to soldering in SMT. Boards for hybrid circuit, requirements and used types. Dielectrics for capacitors, requirements, advantages of polymer and ceramic dielectrics. Effect of orientational polarisation on the temperature dependence of permittivity of polar and non-polar polymers. Ceramic dielectrics of the first and second type. Ferroelectrics for capacitors, BaTiO3 - temperature dependence of permittivity, modifications.
9. Materials technology of transducers and displays. Types of transducers. Hysteresis loop of BaTiO3, saturation and remanent polarisation, coercive field. Comparison of saturation polarisation and Curie temperature of BaTiO3 and PZT ceramics. Equilibrium phase diagram of PbZrO3 and PbTiO3 system (PZT). Steps in manufacture of polarised PZT ceramics. Applications of PZT ceramics. Pyroelectric sensor, pyroelectric coefficient, used materials, mechanisms of charge decay. Principle of chemovoltaic oxygen sensor, material used for solid electrolyte. Light emitting and light modulating methods. Wavelengths and photon energies range of visible light. Chief characteristics of phosphors. Cathodoluminiscence used phosphors and activators, their efficiency. LED, dependence of wavelength of emission from GaAs - GaP. Liquid crystal's types for displays, arrangement and function of the LC-displays.
10. Materials technology in optoelectronics. Advantages of optical communications. Definition of coherent light. Main types of light sources in optoelectronics. Structure of LED based on GaAsP. Methods of PN junction manufacturing in GaAsP solid solution. Methods of lattice parameters adapting between GaAs and GaAsP systems. Structure of laser diode. Refractive index of core and cladding region in optical fibres. Composition of optical fibres for long-distance, medium distance, and short distance communication. Structure of optical cable. The microstructural sources of attenuation in an optical fibre. Preform manufacture for fibre drawing. Methods of planar waveguides manufacture. Photodetectors, materials for photoresistors and photodiodes.
11. Materials technology for superconductors. Diffusion and CVD technology of planar superconductors. The steps of manufacture of superconducting Nb3Sn wires and conductors. The method of stabilisation of superconducting state in superconductors. The methods of high-temperature warm ceramic superconductors manufacture. Snags and advantages of ceramic superconductors in comparison to metallic superconductors.
12. Materials technology for semiconductors. Advantages of silicon in comparison to germanium. SiO2 layers, their properties and methods of their manufacture. 'Electronics grade' silicon production. Advantages of GaAs in comparison to silicon. Methods of PN junction manufacture, epitaxial growth, CVD method, diffusion method and ion implantation. Method for boron diffusion into silicon, concentration profile of dopant before and after annealing. Ion implantation, source of ions, normal and ions channelling concentration profile. The role of annealing after ion implantation.
13. Materials reliability in microelectronics. Electromigration and IC interconnects. Condition for steady state, condition for electromigration to a failure, expression for time to failure and its application in accelerated lifetime tests. Relation between microstructure and activation energy of electromigration. Ageing of solder microjoints. Ageing of Si interface. Materials and processes in microelectronics packaging.
14. Materials technology of magnetics. Manufacturing of magnetic-soft steels, Goss and cubic texture, rapidly quenched magnetics, CVD technology. Manufacturing of NiFe alloys, ferrits and magnetic powders. Technology of ALNICO and samarium-cobalt magnetic materials. Materials and technology for magnetic recording and for magneto-optical recording.

								Prof.Ing.Václav Bouda,CSc