Alloys
Chemistry: Cambridge International GCSE Supplement, topic 9.3.1
Metal Alloys
An alloy is a metal that is mixed with other elements. By adding these other elements, we can change a metal's properties. Most metals that we use in everyday life are alloys.
Bronze
- Bronze is an alloy of copper and tin.
- Adding tin increases the hardness of the material.
- Uses include making coins, electrical hardware and statues.
Brass
- Brass is an alloy of copper and zinc.
- Adding zinc makes the material more malleable.
- Uses include door fittings and water taps.
Gold
- Pure gold is soft and so jewellers will often add metals such as silver, copper and zinc to produce a more resilient substance.
- Carats provide a measure for the purity of a gold alloy:
- 24 carats = 100% gold.
- Therefore, 18 carats = 75% gold.
Steel
- Steels are alloys of iron that contain carbon as well as other metals.
- High carbon steels are strong but brittle. Uses include making cutting tools and blades.
- Low carbon steels are soft but malleable. Uses include making car bodies.
- Stainless steels (steels containing chromium and nickel) are strong and resistant to corrosion. Uses include cooking utensils and cutlery.
Aluminium
- A key feature of aluminium alloys is their low density, which makes them suitable for use in manufacturing aircrafts.
- Other uses include armour plating for military vehicles.
Test yourself on Alloys
Metals added to pure gold to make it more resilient