Metals

• the three main categories of metals are

  • ferrous - contains iron and carbon
  • non-ferrous - does not contain iron
  • alloys - combination of metals to increase properties
• metals are made up of


  crystals that contain atoms and molecules which causes them to have good strength in comprehension and tension
• all metals are extracted from ores which are found in the earth
• the only metal that can be found in a useable form is gold
• metals and their ore names aren't always the same


  • iron - magnetite, haematite
  • copper - chalcopyrite
  • aluminium - bauxite
  • lead - galena
  • tin - cassiterite
  • zinc - zinc blende
• iron separated from its ore is known as pig iron
• ferrous metals rust easily which is a large disadvantage. the iron in the metal oxidises causing rust which happens to other metals but not aa quickly
• ferrous materials and properties


  cast iron - hard outer skin but brittle - cooking pans

  mild steel (low carbon) - ductile, hight tensile strength - chair legs

  medium carbon steel - harder than mild but less ductile - tools

  high carbon steel - harder than medium - drill bits
• non-ferrous metals contain no iron meaning they do not rust
• non-ferrous metals and properties


  • aluminium - lightweight, ductile, malleable - drink cans
  • copper - lightweight, ductile, malleable, can be soldered - gas pipes
  • zinc - low melting point - galvanising steel
  • lead - heavy, soft, malleable - food can coatings
  • titanium - hard, stronger but more lightweight than steel - joint replacements
  • precious metals - malleable, ductile - jewellery
• ferrous alloys are a mixture of metals combined to improve their properties - this would be done to change the melting point, colour and the resistance to corrosion
• ferrous metals and properties

  • stainless steel - tough, hard - kitchenware
  • high speed steel - hard, tough, heat resistant - tool blades
  • die steel - hard, tough with carbon - press tools
  • bronze - tough, corrosion resistant - coins
  • brass - corrosion resistant, good electrical and thermal conductor - boat fittings
  • duralumin - equal strength to steel but lightweight, ductile - vehicle parts
  • pewter - malleable, low melting point - trophies
• metal can be stocked and bought in bar, rod and tube (in square rectangle and round) can also be in a variety of profiles such as L shaped (angle) and U shaped (channel)

  can also be different thicknesses and diameters
• gathering ores must be done through mining which has a social and ecological impact on the world - deforestation can occur, as well as a mass production of carbon