5 Properties of materials Mechanical properties of materialsStrength, Toughness, Hardness, Ductility,Elasticity, Fatigue and CreepPhysical propertiesDensity, Specific heat, Melting and boiling point,Thermal expansion and conductivity,Electrical and magnetic propertiesChemical propertiesOxidation, Corrosion, Flammability, Toxicity, …
6 Material Specification Chemical compositionMechanical properties – Strength, hardness (under various conditions: temperature, humidity, pressure)Physical properties – density, optical, electrical, magneticEnvironmental – green, recycling
7 Metals Ferrous Metals Super alloys Non-ferrous metals Cast irons SteelsSuper alloysIron-basedNickel-basedCobalt-basedNon-ferrous metalsAluminum and its alloysCopper and its alloysMagnesium and its alloysNickel and its alloysTitanium and its alloysZinc and its alloysLead & TinRefractory metalsPrecious metals
8 General Properties and Applications of Ferrous Alloys Ferrous alloys are useful metals in terms of mechanical, physical and chemical properties.Alloys contain iron as their base metal.Carbon steels are least expensive of all metals while stainless steels is costly.
9 Carbon and alloy steels Carbon steelsClassified as low, medium and high:Low-carbon steel or mild steel, < 0.3%C, bolts, nuts and sheet plates.Medium-carbon steel, 0.3% ~ 0.6%C, machinery, automotive and agricultural equipment.High-carbon steel, > 0.60% C, springs, cutlery, cable.
10 Carbon and alloy steels Steels containing significant amounts of alloying elements.Structural-grade alloy steels used for construction industries due to high strength.Other alloy steels are used for its strength, hardness, resistance to creep and fatigue, and toughness.It may heat treated to obtain the desired properties.
11 Carbon and alloy steels High-strength low-alloy steelsImproved strength-to-weight ratio.Used in automobile bodies to reduce weight and in agricultural equipment.Some examples are:Dual-phase steelsMicro alloyed steelsNano-alloyed steels
12 Stainless steelsCharacterized by their corrosion resistance, high strength and ductility, and high chromium content.Stainless as a film of chromium oxide protects the metal from corrosion.
20 Processing and Service Characteristics of Common Tool and Die Steels
21 Aluminium and aluminium alloys Factors for selecting are:High strength to weight ratioResistance to corrosionHigh thermal and electrical conductivityEase of machinabilityNon-magnetic
22 Magnesium and magnesium alloys Magnesium (Mg) is the lightest metal.Alloys are used in structural and non-structural applications.Typical uses of magnesium alloys are aircraft and missile components.Also has good vibration-damping characteristics.
23 Copper and copper alloys Copper alloys have electrical and mechanical properties, corrosion resistance, thermal conductivity and wear resistance.Applications are electronic components, springs and heat exchangers.Brass is an alloy of copper and zinc.Bronze is an alloy of copper and tin.
24 Nickel and nickel alloys Nickel (Ni) has strength, toughness, and corrosion resistance to metals.Used in stainless steels and nickel-base alloys.Alloys are used for high temperature applications, such as jet-engine components and rockets.
25 SuperalloysSuperalloys are high-temperature alloys use in jet engines, gas turbines and reciprocating engines.
26 Titanium and titanium alloys Titanium (Ti) is expensive, has high strength-to-weight ratio and corrosion resistance.Used as components for aircrafts, jet-engines, racing-cars and marine crafts.
27 Refractory metalsRefractory metals have a high melting point and retain their strength at elevated temperatures.Applications are electronics, nuclear power and chemical industries.Molybdenum, columbium, tungsten, and tantalum are referred to as refractory metal.
28 Other nonferrous metals BerylliumZirconiumLow-melting-point metals: - Lead - Zinc - TinPrecious metals: - Gold - Silver - Platinum
29 Special metals and alloys Shape-memory alloys (i.e. eyeglass frame, helical spring)Amorphous alloys (Metallic Glass)NanomaterialsMetal foams
30 Heat Treatment of Metals AnnealingFull annealingNormalising (faster rate of cooling)Recovery annealing (longer holding time, slower rate of cooling,)Stress relieving (lower temperature)Martensite formation in steelAustenitizing (conversion to austenite)Quenching (control cooling rateTempering (reduce brittleness)
31 Heat Treatment of Metals Precipitation hardeningSolution treatment (-phase conversion)quenchingprecipitation treatment (aging)Surface hardeningCarburizingNitridingCarbonitridingChromizing and Boronizing
41 Classification of Polymers ThermoplasticsThermosetsElastomers
42 PolymersThermoplastics - reversible in phase by heating and cooling. Solid phase at room temperature and liquid phase at elevated temperature.Thermosets - irreversible in phase by heating and cooling. Change to liquid phase when heated, then follow with an irreversible exothermic chemical reaction. Remain in solid phase subsequently.Elastomers - Rubbers
46 Classification of Composite Materials Metal Matrix CompositesCeramic Matrix CompositesPolymer Matrix Composites
47 Metal Matrix Composites (MMC) Composite MaterialsMetal Matrix Composites (MMC)Mixture of ceramics and metals reinforced by strong, high-stiffness fibersCeramic Matrix Composites (CMC)Ceramics such as aluminum oxide and silicon carbide embedded with fibers for improved properties, especially high temperature applications.Polymer Matrix Composites (PMC)Thermosets or thermoplastics mixed with fiber reinforcement or powder.