1. Types of Material
IE 351
Lecture 3

2. Why Materials ???
Ashby,: Material Selection in Mechanical Design

3. Engineering Materials

4. Materials
Ferrous metals: carbon-, alloy-, stainless-, tool-and-die steels
Non-ferrous metals: aluminum, magnesium, copper, nickel,
titanium, superalloys, refractory metals,
beryllium, zirconium, low-melting alloys,
gold, silver, platinum, …
Plastics: thermoplastics (acrylic, nylon, polyethylene, ABS,…)
thermosets (epoxies, Polymides, Phenolics, …)
elastomers (rubbers, silicones, polyurethanes, …)
Ceramics, Glasses, Graphite, Diamond, Cubic Boron Nitride
Composites: reinforced plastics, metal-, ceramic matrix composites
Nanomaterials, shape-memory alloys, superconductors, …

5. Properties of materials
Mechanical properties of materials
Strength, Toughness, Hardness, Ductility,
Elasticity, Fatigue and Creep
Physical properties
Density, Specific heat, Melting and boiling point,
Thermal expansion and conductivity,
Electrical and magnetic properties
Chemical properties
Oxidation, Corrosion, Flammability, Toxicity, …

6. Material Specification
Chemical composition
Mechanical properties – Strength, hardness (under various conditions: temperature, humidity, pressure)
Physical properties – density, optical, electrical, magnetic
Environmental – green, recycling

7. Metals Ferrous Metals Super alloys Non-ferrous metals Cast irons
Steels
Super alloys
Iron-based
Nickel-based
Cobalt-based
Non-ferrous metals
Aluminum and its alloys
Copper and its alloys
Magnesium and its alloys
Nickel and its alloys
Titanium and its alloys
Zinc and its alloys
Lead & Tin
Refractory metals
Precious 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 steels
Classified 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 steels
Improved strength-to-weight ratio.
Used in automobile bodies to reduce weight and in agricultural equipment.
Some examples are:
Dual-phase steels
Micro alloyed steels
Nano-alloyed steels

12. Stainless steels
Characterized by their corrosion resistance, high strength and ductility, and high chromium content.
Stainless as a film of chromium oxide protects the metal from corrosion.

13. Stainless steels
Five types of stainless steels:
Austenitic steels
Ferritic steels
Martensitic steels
Precipitation-hardening (PH) steels
Duplex-structure steels

14. Typical Selection of Carbon and Alloy Steels for Various Applications

15. Mechanical Properties of Selected Carbon and Alloy Steels in Various Conditions

16. AISI Designation for High-Strength Sheet Steel

17. Room-Temperature Mechanical Properties and Applications of Annealed Stainless Steels

18. Tool and die steels
Designed for high strength, impact toughness, and wear resistance at a range of temperatures.

19. Basic Types of Tool and Die Steels

20. Processing and Service Characteristics of Common Tool and Die Steels

21. Aluminium and aluminium alloys
Factors for selecting are:
High strength to weight ratio
Resistance to corrosion
High thermal and electrical conductivity
Ease of machinability
Non-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. Superalloys
Superalloys 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 metals
Refractory 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
Beryllium
Zirconium
Low-melting-point metals: - Lead - Zinc - Tin
Precious metals: - Gold - Silver - Platinum

29. Special metals and alloys
Shape-memory alloys (i.e. eyeglass frame, helical spring)
Amorphous alloys (Metallic Glass)
Nanomaterials
Metal foams

30. Heat Treatment of Metals
Annealing
Full annealing
Normalising (faster rate of cooling)
Recovery annealing (longer holding time, slower rate of cooling,)
Stress relieving (lower temperature)
Martensite formation in steel
Austenitizing (conversion to austenite)
Quenching (control cooling rate
Tempering (reduce brittleness)

31. Heat Treatment of Metals
Precipitation hardening
Solution treatment (-phase conversion)
quenching
precipitation treatment (aging)
Surface hardening
Carburizing
Nitriding
Carbonitriding
Chromizing and Boronizing

32. Heat Treatment of Steel

33. Precipitation Hardening
Solution treatment
Quenching
Precipitation treatment

34. Furnaces for Heat Treatment
Fuel fire furnaces
gas
oil
Electric furnaces
batch furnaces
box furnaces - door
car-bottom furnaces - track for moving large parts
bell-type furnaces - cover/bell lifted by gantry crane
continuous furnaces

35. Furnaces for Heat Treatment
Vacuum furnaces
Salt-bath furnaces
Fluidized-bed furnaces
Some of the furnaces have special atmosphere requirements, such as carbon- and nitrogen- rich atmosphere.

36. Surface Hardening Methods
Flame hardening
Induction heating
High-frequency resistance heating
Electron beam heating
Laser beam heating

37. Surface Hardening Methods
Induction
heating
High frequency
resistance
heating

38. Classification of Ceramics
Traditional ceramics
New ceramics
Glass

39. Ceramics Traditional ceramics New ceramics clays: kaolinite
silica: quartz, sandstone
alumina
silicon carbide
New ceramics
oxide ceramics : alumina
carbides : silicon carbide, titanium carbide, etc.
nitrides : silicon nitride, boron nitiride, etc.

40. Glass ceramics - polycrystalline structure
Glass products
window glass
containers
light bulb glass
laboratory glass
glass fibers
optical glass
Glass ceramics - polycrystalline structure

41. Classification of Polymers
Thermoplastics
Thermosets
Elastomers

42. Polymers
Thermoplastics - 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

43. Thermoplastics Acetals Acrylics - PMMA
Acrylonitrile-Butadiene-Styrene - ABS
Cellulosics
Fluoropolymers - PTFE , Teflon
Polyamides (PA) - Nylons, Kevlar
Polysters - PET
Polyethylene (PE) - HDPE, LDPE
Polypropylene (PP)
Polystyrene (PS)
Polyvinyl chloride (PVC)

44. Thermosets
Amino resins
Epoxies
Phenolics
Polyesters
Polyurethanes
Silicones

45. Elastomers Natural rubber Synthetic rubbers butadiene rubber
butyl rubber
chloroprene rubber
ethylene-propylene rubber
isoprene rubber
nitrile rubber
polyurethanes
silicones
styrene-butadiene rubber
thermoplastic elastomers

46. Classification of Composite Materials
Metal Matrix Composites
Ceramic Matrix Composites
Polymer Matrix Composites

47. Metal Matrix Composites (MMC)
Composite Materials
Metal Matrix Composites (MMC)
Mixture of ceramics and metals reinforced by strong, high-stiffness fibers
Ceramic 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.

48. Composite Materials
1D fibre
Woven fabric
Random fibre

49. Composite Materials

50. Taxonomy of Materials Selection
Ashby,: Material Selection in Mechanical Design