1. Metals & Alloys, Plastics

2. Metals Material extracted from an ore
Metals usually shiny & are good conductors of electricity and heat
Some are corrosion-resistant
See table 12.16, page 379

3. Alloys
Result of mixing a metal with one or more metallic or non-metallic substances
Two types of alloys:
1. Ferrous alloys- main constituent is iron
ex. Steel (iron & carbon, often Nickel, chrome, zinc),
Cast iron (iron & carbon)

4. 2. Non-ferrous- an alloy whose main constituent is a metal other than iron
ex. Brass (copper & zinc)
Bronze (copper & tin)
Aluminum alloy (small amount of
copper, silicon etc.)

5. Plastics A manufactured material made of polymers
Polymers are made of chain of multiple identical units called monomers
Most come from petroleum or natural gas

6. Two types of Plastics Thermosetting- harden permanently under
energy (heat etc.)
- provides plastic with rigidity
Thermoplastics
soften when heated & harden when cooled
Can be reshaped when softened, new shape when cooled