Metals

Ferrous metals

• contain iron
• prone to rusting
• magnetic

Non - ferous Metals

• do not contain iron
• do not rust
• not magnetic
• more expensive

Alloys

• 2 or more metals mixed togther
• or a metal combined with a different material
• ehance the properties by combining more than one metal

Alloys can be used to:

• change the colour
• change the strength
• change the electrical conductivity

Most metals become less hard and more ductile when they are heated

Work Hardening

• the more the metals are worked and processed, the harder it becomes to work with them

Annealing

• is the process of heating the metal until it is cherry red, making it easier to work with

Hardening

• is the process of heating the metal to cherry red then rapidly cooling it, in water, for example.
• the rapid cooling is know as 'quenching'
• mainly used for carbon steel

Tempering

• often done after hardening
• apply heat, then quench
• leaves a grey coloured coating toughening the metal and preventing it from being brittle