Introduction to materials
Definition of material. Importance of materials in history. Classification of materials: metallic, ceramic and polymeric. Other classification criteria: structural and functional materials, crystalline and amorphous. Composite materials. Properties of materials: mechanical, physical and chemical. Relationship between composition, structure and properties. Atomic structure, microstructure and macrostructure. States of matter. Structure of solids. Order concept. Crystalline and amorphous solids. Main characteristics crystalline solid. Anisotropy. Lattices and elementary cells. Crystal systems and Bravais lattices. Ideal solids: basic assumptions. Coordination number and packing factor. Lattice and molecular solids. Covalent solids. Sp3 hybridization of carbon. Structure and properties of the diamond. Carbon polymorphism. Sp2 hybridization. Structure and properties of graphite. Ionic solids. Stable and unstable geometries. Cationic and anionic coordination numbers. Magnus rule. Two-dimensional and three-dimensional gaps. Characteristics of ionic solids. Metallic solids. Model of rigid spheres. Compact arrangements in plan and space. Elementary cells EC, CFC, CCC. Metallic solid characteristics. Real solids. Defects in solids. Defect classification. Point defects of physical and chemical nature. Role of point defects on the characteristics of some materials. Line defects: corner and screw dislocation. Surface defects: grain boundaries. Mechanism of solidification of a metal. Nucleation and growth. Fine or coarse grained crystals.
Mechanical behavior of materials. Elastic and plastic elementary behaviors and their interpretation on an atomic scale. Ductile and fragile behavior. Mechanical behavior in the presence of defects. Griffith experience. Sliding mechanism of dislocation in a lattice. Role of dislocations and grain boundaries on the ductility of metals. Hardening.
Classification of mechanical tests. Mentions on UNI and UNI EN standards. Tensile test. Stress-strain curve. Elasticity module. Hooke's law. Yield stress. Conventional yield strength. Breaking load. Percentage elongation at break. Ductility. Toughness. Characteristic stress-strain curves. Mentions on viscous behavior. Creep and relaxation. Hardness and hardness tests. Mohs scale, durometers, sclerometers. Hardness-resistance correlation. Resilience. Charpy pendulum. Ductile-brittle transition interval. Fatigue failure. Fatigue limit.
Introduction to state diagrams. Examples of state diagrams of pure substance. Gibbs rule. Degree of variance. Working hypothesis. Binary state diagrams. Description of state diagrams under conditions of total miscibility and zero miscibility between solid phase components. Leverage rule. Solid solutions. Eutectic transformation. Intermediate compounds with congruent and incongruent fusion. Peritectic transformation. State diagrams in conditions of partial miscibility between solid phase components. Summary of invariant transformations. Primary crystallization fields.
Main categories of materials
Metallic materials
Ferrous and non-ferrous metallic materials. Notes on iron. Role of carbon on the strength of steels. Definition of steel and cast iron. Solid substitutional and interstitial solutions. Intermetallic compounds. Polymorphism of iron and solubility of C in Fe. Solid interstitial solutions: Ferrite and Austenite. Regular and irregular octahedral gaps.
Cooling of steels: equilibrium and non-equilibrium microstructures. Displacement transformation from Fe-γ to Fe-α. Intermetallic compounds: Cementite. Structural constituents: Lamellar perlite. Martensite: formation mechanism and mechanical properties. Notes on the iron-cementite phase diagram. Notes on the production of steel by primary steelmaking. Blast furnace: description and operation. Cast iron and blast furnace slag. Refining of cast iron. Steel strengthening treatments. Mechanical treatments: obstacles to the movement of dislocations. Heat treatments: annealing, normalization, hardening. Hardening media. Tempering. Sorb. Surface hardening. Thermochemical treatments: cementation and nitriding. Steel classification. Carbon steels and alloyed and unalloyed steels. Notes on corrosion: reaction mechanisms, factors that influence it, main forms of corrosion and protection methods. Stainless steels: composition and microstructures. Characteristics and applications of stainless steels. Notes on cast irons: classification, strengths and weaknesses. Characteristics and main fields of application of non-ferrous metallic materials. Aluminum and light alloys. Anodized aluminum. Titanium and its alloys: characteristics and main fields of application. Shape memory alloys.
Ceramic materials
Traditional ceramic materials
Introduction to traditional ceramic materials. Definition and Classification. Production cycle of ceramics. Raw materials: clays, thinners, fluxes, complementary materials. The structure of clays: tetrahedral and octahedral sheets. Rheology of water-clay systems. Coverings: showcases and enamels. Forming techniques: pressing, extrusion and casting. Drying and firing: porous and compact paste ceramic.
Advanced ceramic materials
Definition, fields of application, production processes. Ceramic powders for ACM: characteristics and main production techniques (solid state reaction, fusion, vapor phase reaction, solution reaction). Spray drying technique. Forming and compaction techniques: uniaxial pressing, isostatic pressing, inject molding, tape casting. Sintering: definition and general information. Sintering techniques. Optimization of sintering parameters. Solid state sintering mechanism: two-sphere model. Sinter necks. Solid state atomic diffusion. Mechanical and physical properties of ceramic materials. Density and linear thermal expansion. Theoretical and real resistance of MCs. Mechanical tests suitable for the characterization of an MC. Evaluation of the resistance of an MC in statistical terms: probability of breakage and survival. Weibull curves. MC toughening mechanisms. Stabilized zirconia.
Glasses
Introduction to glass and historical notes. Features and applications. Amorphous solids and crystalline solids. Kinetic theory of vitrification. Production cycle of glass products. Structure of the glass. Glass lattice formers and modifiers. Stabilizing and bleaching glass lattice modifiers. Intermediate oxides. Characteristic points of glass: workability, softening, annealing and deformation. Processing interval. Refining of the glass. Forming techniques. Pressing and blowing. Float glass. Annealing. Composition and characteristics of some commercial glasses. Special glass: silica glass, boron and lead glass. Tempered glass: thermal and chemical hardening. Stratified glass. Chemical stability of glasses.
Polymeric materials
Introduction to Polymers. The bonds in polymers. The structure of Polymers. The molecules of hydrocarbons. The molecules of hydrocarbons: alkanes, alkenes, alkynes. The main functional groups of organic chemistry. Role of repeating units in the formation of polymeric macromolecules. Homopolymers and copolymers. Average molecular weight. Degree of polymerization. Functionality of a monomer. Stereoisomerism: atactic, isotactic, syndiotactic polymers. Degree of crystallinity. Molecular structures. Polymer classification. Thermoplastic and thermosetting polymers, elastomers. The glass transition temperature of amorphous and semicrystalline polymers. Polymerization Mechanisms: chain polymerization and step polymerization. Vinyl Polymers: some examples. Polycondensation and polyaddition. Examples of polymerization: polyamides, polyesters, phenolic resins, polyurethane. Physical and mechanical characteristics of polymers. Dependence of mechanical behavior on time and temperature. Viscous behavior of amorphous polymers. Relaxation module. Viscoelastic creep. Fracture and fatigue in polymeric materials. Polymerization techniques: in mass, in solution, in suspension, in emulsion. Processing technologies: molding, extrusion, blowing and thermoforming. Production of polymeric fibers and films.
Composite materials
Introduction to composite materials. Natural and artificial composite materials. Constituents of composite materials: matrix, reinforcement and interface. Classification of composites: based on reinforcement and matrix. Examples of composites with particles and laminates. Role of reinforcement. Critical length of the fibers. Main polymeric matrices: epoxy and polyester. Composites with ceramic and metal matrix. Main types of fibers used as reinforcement. Glass fibers: chemical composition, characteristics and applications. Aramid fibers: nomex and kevlar. Carbon fibers.
Properties of materials
Electrical properties
Ohm's law. Electrical resistivity of metals. Electronic and ionic conduction. Energy band structure. Conduction in metals. Semiconductors and insulators. Electrical conduction in intrinsic semiconductors. N-type and p-type extrinsic semiconductors. Dropping of materials. Electrical properties of ceramic materials and polymers.
Thermal properties
Definition of thermal properties. Thermal capacity. Thermal expansion of materials. Thermal conductivity and heat conduction mechanisms. Conduction of heat in metals, ceramics and polymers.
Optical properties
Definition of optical properties of materials. Interaction of light with solids. Optical properties of metals. Optical properties of non-metals: refraction, reflection, absorption, transmission. Color, opacity and translucency.
Magnetic properties
Magnetic fields. Magnetic induction. Permeability and magnetic susceptibility. The types of magnetism: diamagnetism, paramagnetism, ferromagnetism, antiferromagnetism, ferrimagnetism. Ferromagnetic domains. Magnetization and demagnetization of a ferromagnetic material.