Metals & Alloys
Design & Technology: AQA GCSE, topic 1.6.2
Metals and Alloys
Metals are split into three categories ferrous metals, non-ferrous metals and alloys.
Ferrous metals
- Ferrous metals have the following characteristics:
- These metals contain iron (ferrite).
- These metals are magnetic.
- These metals without a protective coating will rust if exposed to moisture.
- Other metals and compounds can be mixed with these metals to enhance their properties such as carbon.
Common ferrous metals
- Common types of ferrous metals include:
- Mild steel.
- Steel.
- Cast iron.
Non-ferrous metals
- Non-ferrous metals have the following characteristics:
- These metals do not contain iron (ferrite).
- These groups of metals are generally not magnetic.
- These metals do not rust.
- These metals can oxidise which causes the surface of the metals to change colour. This rarely affects its characteristics but can make it more visually appealing.
Common non-ferrous metals
- Common types of non-ferrous metals include:
- Copper.
- Gold.
- Silver.
- Platinum.
Alloys
- Alloys have the following characteristics:
- Alloys are a result of two or more metals mixed together, where at least one is a pure metal (non-ferrous).
- These metals are combined to improve their working properties.
- These metals are combined to improve their aesthetics.
Common alloys
- Common types of alloys include:
- Brass.
- Stainless steel.
- Tungsten.
- Cobalt.
Ferrous Metals
Ferrous metals are commonly used in everyday objects such as car body parts. They could even be used in some of your GCSE projects.
Low carbon steel
- Bright grey in appearance with a smooth texture.
- This metal will oxidise (rust) if not protected.
- Low carbon steel is tough and ductile.
- This metal can be formed, welded and brazed easily.
Common uses of low carbon steel
- Common uses of low-carbon steel include:
- Car body parts.
- Nuts and bolts.
- Screws.
- Nails.
- Steel beams in the building industry.
High carbon steel
- Bright grey in appearance with a smooth texture.
- This metal will oxidise (rust) if not protected.
- Much harder than low-carbon steel due to carbon content.
- This metal is less ductile and very hard-wearing.
Common uses of high carbon steel
- Common uses of high-carbon steel include:
- Blades.
- Scissors.
- Tools.
- Wood and metal cutting tools, such as drill bits.
Cast iron
- Dull grey in appearance with a rough texture.
- This metal is less prone to oxidisation (rust).
- Very hard but can be brittle when the metal is thin in cross section.
- This metal can be cast into complex shapes.
Common uses of cast iron
- Common uses of cast iron include:
- Kitchen pots and pans.
- Manhole covers.
- Post boxes.
- Heavy-duty bases, such as those used to secure parasols.
Test yourself on Metals & Alloys
Which is NOT a type of non-ferrous metal?
What is NOT a common type of alloy?
Which is NOT a common use of cast iron?
Which of these metals is least prone to oxidisation (rust)?