Life Cycle Assessment and Materials

• what is corrosion

  when a metal oxidises over time it becomes weaker
• what is rusting

  when iron reacts with oxygen and water to produce hydrated iron oxide
• how can corrosion be prevented

  Physical barriers - painting , greasing

  sacrificial protections and galvanisation

  electroplating
• what is bronze properties and use

  an alloy of copper and tin

  hard

  statues and coins
• brass use and properties

  An alloy of copper and zinc

  hard

  instruments and taps
• gold - properties and use

  soft and malleable

  unreactive - shiny - resistant to corrosion

  jewellery
• what is the carat system used for

  Measures the percemtage of gold in the alloy

  24carat = 100%
• how are the different steel alloys different ?

  high carbon steel- strong, brittle

  low carbon steel - softer more easily shaped

  stainless steel - chromium and nickel and iron - hard resistant to rust
• Aluminium use and properties

  Doesn’t react with water

  low density

  foil and planes
• properties of glass

  transparent

  hard

  brittle
• what is soda lime glass

  A mix of silicone dioxide sodium carbonate and limestone
• what is borosilicate glass

  silicone dioxide and boron trioxide

  Pyrex has a much high melting point than sodalime glass
• what is the bonding in ceramics

  Ionic and covalent bonds
• what are the properties of LDPE

  Flexible unreactive
• what are the properties of HDPE

  strong , flexible , resistant to shattering, resists chemical attack
• what is a thermosoftening plastic

  plastics that melt when heated because they do not have covalent crosslinks between neighbouring polymer molecules
• what is a thermosetting plastic

  A plastic that doesn’t melt when heated

  tend to burn before melting because they have covalent cross links between adjacent polymer chains
• what is a composite made from

  the reinforcement and the matrix
• name some examples of composites

  Reinforced concrete - steel and concrete

  fibreglass - glass fibres and polymer resin

  carbon fibre reinforced polymer - carbon fibres and polymer resin

  chipboard - wood chips and resin glue