basics of engineering materials

3. Different Bonds (Primary bonds):

4. Metals
1. Metallic Bonds
2. High thermal conductivity
3. High electrical conductivity
4. Good ductility
5. High toughness
6. High Strength
7. High Hardness
8. Malleable

5. Ferrous and Non-Ferrous Metals

6. Engineering
Materials
Metals
Ferrous
Iron
Steel
Pig iron
Cast iron
Wrought
iron
Non-Ferrous
Copper
Aluminium
Zinc
Tin
Lead

7. Steel
• Steel is an alloy that consists mostly of iron
and has a carbon content between 0.2% and
1.8 %
• Carbon is the most common alloying material
for iron, but various other alloying elements
are used, such as manganese, chromium,
vanadium, molybdenum, tungsten, etc.

8. Stainless steel
• Stainless steel is a steel alloy with a minimum
of 10 to 11% chromium content.
• It does not corrode.

9. High-speed steel
• High speed steel is commonly used in tool bits
and cutting tools.
• It can withstand higher temperatures without
losing its hardness. This property allows HSS
to cut faster than high carbon steel, hence the
name high speed steel.

10. Non-ferrous metals
• Copper
• Aluminium
• Zinc
• Tin
• Lead

11. Copper
Copper
good heat and electrical conductivity
resistance to corrosion

12. Aluminium
• Aluminium
• the third most abundant element (after
oxygen and silicon), and the most abundant
metal in the Earth’s crust

13. Aluminium
• low density and ability to resist corrosion good
conductivity
• structural components made from aluminium
and its alloys are vital to the aerospace
industry and are important in other areas of
transportation and structural materials

15. Alloys examples
Bronze: (copper 90%+ 10 % Tin)
Brass: (65 % copper+ 35% Zinc)

16. Ceramics
• Non metallic solids made of inorganic compounds
such as oxides, nitrides, borides and carbides
• Covalent and ionic bonds
• Most of them are Crystalline in nature and some
are amorphous (glass)
• Poor ductility and malleability
• Insulating in nature and low thermal conductivity
• High hardness
• High melting point

17. • High compressive strength comparative to
tensile and shear strength
• High resistance to corrosion, wear and current
• Hot hardness
• Example:
• SiC, Al2O3, WC, SiN, BN, Macor etc.
• Used as abrasives, cutting tool, electrical
insulators, bio-ceramics for bone implant and
tooth, refractory tiles

18. Polymers
• Compound consisting of long chain molecules
and each molecules is made up of repeating
units connected together.
• TYPES
• Thermoplastic (eg. Polyethylene, PVC, Nylon)
• Thermosetting (polysters, epoxy etc.)
• Elastomers (Natural rubber)

19. • Low strength
• Low stiffness
• Low hardness
• Low density
• High thermal expansion coefficient
• Low melting and softening temperature
• Crystalline and amorphous structures
• High ductility
• Low tensile strength
• Insulators

20. • Composites (eg. concrete)

24. Types
• Metal matrix composites
• Ceramic matrix composites
• Polymer matrix composites

25. • High strength
• High stiffness
• Lighter in weight
• High fatigue strength
• High toughness
• Anisotropic in nature
• Expensive
• Slow manufacturing

26. Selection of materials