alloys

• • alloys are not pure metals, but contain other elements
  • alloys are harder than metals
  • alloys have different sized atoms
  • atoms distort layers of atoms in pure metal
  • so, greater force needed for layers to slide over each other
• • bronze is an alloy of copper and tin
  • bronze is harder than copper
  • it is used to make medals and statues
• • brass is an alloy of copper and zinc
  • brass is more malleable than bronze
  • it is used in areas of low friction, such as water taps
• • gold alloys are used to make jewellery because pure gold is very soft
  • gold is used as an alloy with copper, zinc, and silver
  • pure gold is 24 carat
  • 75% gold is 18 carat
• • aluminium alloys are used to make aircrafts
  • aluminium allows have low density
  • pure aluminium is too soft
• • steels are alloys of iron that contain carbon and other metals
  • low carbon steel is malleable and used in car bodies
  • high carbon steel is very strong, inflexible but brittle and is used in bridges
  • stainless steel contains chromium and nickel are hard and corrosion resistant and used in cutlery