28184 - Material Science and Technology: Structure and Properties L

Learning outcomes

The aim of the course is to give the students a sound knowledge of the different classes of materials in order to:

a) understand the relationship between structure, microstructure and materials properties,

b) individuate the technologies more suited for a material to be transformed into a industrial product,

c) be acquainted with  the available techniques for analysis and testing of materials.

Course contents

Materials science as a link between theoretical and applied disciplines. Materials classification and evolution. Competition and sinergy between materials. Resources and reserves of materials. Energy content and environmental impact of materials. Disposal and recycling of materials.
 
Materials structure and microstructure. Structure and interatomic bond: covalent, ionic and metallic solids. Intra- and intermolecular bonds in polymeric solids. Crystal structure of metals: CFC, HCP and BCC lattices. Crystal structure of ionic ceramics. Diamond and covalent solids. Silica and silicates. Crystallinity in polimeric solids. Non-crystalline solids: inorganic glasses and  amorphous polymers. Criystal systems and unit cells.  Indices of positions, directions and planes in the cubic cell. Structural analysis by XR diffraction techniques. Structure defects in crystalline solids: vacancies, interstitials, dislocations and grain boundaries.
 
Structure related properties: density, thermal expansion and elastic behaviour. Elastic moduli and interatomic bond strength. The stiffness of macromolecular solids: thermoplastics, thermosettings and fibers. Elastomers. Elastic properties of composite and foamed materials. Anelasticity and viscoelasticity.
 
Materials microstructure: components, phases and micro-constituents. Substitutional and interstitials solid solutions. Intermediate phases and  compounds. Free energy-composition diagrams. Binary equilibrium diagrams of metals and ceramics.  Ternary diagrams in ceramic technology. Copolymers and polymer blends. Nanostructured materials and related technologies.
 
Solidification of metals: homogeneous and heterogeneous nucleation. Growth morphology and solidification microstructures. Metal forming by casting techniques. Microstructure and defects of metal castings. Crystalline solidification and glass transition. Vitrification of silicate melts. Liquid-phase sintering. Microstructure of polymeric materials. Injection moulding and reactive solidification of polymer melts. Film formation in paints and adhesives. Slip casting. Setting and hardening of lime, plaster and cement mortars.
 
Diffusion controlled solid-phase transformations. Avrami equation and TTT-diagrams. The austenite to pearlite transformation. Precipitation from solid solutions. Sintering and devitrification. Non-diffusive transformations: the austenite to martensite tranformation.
 
Theoretical strength of materials. Plastic deformation of metals: dislocations and slip systems. Yield strength, strain hardening and tensile strength of metals. Strengthening mechanisms in metal alloys. Cold forming of metal components. Recrystallization and grain-growth Hardening and  heat treatments of alloy steels.  Precipitation hardening of aluminum alloys. Plastic deformation and cold drawing of polymeric materials. Plastic forming of ceramic pastes.
 
Rupture strength of ceramic materials: the Weibull modulus. Ductile and brittle fracture. Impact and fracture thoughness. The fatigue ruptureand creep of materials. Hot forming of metals. Glass forming. Extrusion and thermoforming  of plastomers. Moulding of thermosetting polymers.
 
Physical properties of materials. Electronic energy bands in solids: conductors, semiconductors and  insulating materials. Superconductors. Conductive polymers. Intrinsic and extrinsic demiconductors.Semiconductor-based devices. Dielectric properties: insulators and condensators. Piezoelectricity and electrostriction. Magnetic properties. Soft and hard magnetic materials. Electromagnetic transducers. Optical properties: photonic materials and systems. Thermal properties: capacity, conductivity and expansion coefficient. Thermal shock in ceramics.
 
Degradation, corrosion and aging of materials. Wet and dry corrosion of metals. Active and passive protection techniques. Thermal and photochemical degradation of polymeric materials. Chemical corrosion of ceramic materials.

Readings/Bibliography

William F. Smith : “SCIENZA  E  TECNOLOGIA  DEI  MATERIALI”   Ed. McGraw Hill, 2004
Further reading:
1)   W.D:Callister: “SCIENZA E INGEGNERIA DEI MATERIALI”  EdiSES-Napoli 2003
2)   W.Kurz, J.P.Mercier, G.Zambelli “INTRODUZIONE ALLA SCIENZA DEI MATERIALI” Hoepli Ed. 19973)   M.F.Ashby, D.R.H:Jones “ENGINEERING MATERIALS” 2 Voll   Butterworth-Heinemann Ed. 1997
4)  D.Askeland “ THE SCIENCE AND ENGINEERING OF MATERIALS” 3°Ed.  Pergamon 1996
5)   AA.vari “MANUALE DEI MATERIALI PER L'INGEGNERIA” Ed. McGraw Hill

Teaching methods

Lectures are structured so the most important materials properties are analysed and discussed according to a horizontal scheme. The dependence of the mechanical properties on structure and microstructure will be particularly underlined. Much attention is also devoted to the  physical properties, both from the theoretical and practical standpoint. Lectures are integrated by numerical exercises and supported by laboratory experiences.

Assessment methods

The learning level will be assessed by a oral exam, so structured as to verify whether the student is able to correlate the materials behaviour with structure and composition, and to devise a possible technological route  to obtain a  given product.

Office hours

See the website of Angelo Casagrande