Non-Ferrous Metals & Alloys

This lesson covers non-ferrous metals (metals that do NOT contain iron) and their alloys (mixtures of two or more metals). These are essential materials in AQA GCSE Design and Technology (8552), Section 3.1.6.

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What Are Non-Ferrous Metals?

Non-ferrous metals do not contain iron. This gives them two key advantages over ferrous metals:

1. They do not rust (though some may corrode in other ways).
2. They are not magnetic.

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Pure Non-Ferrous Metals

Aluminium

Property	Detail
Colour	Silver-white
Density	Very low — about one-third the weight of steel
Corrosion resistance	Excellent — forms a protective aluminium oxide layer
Conductivity	Good electrical and thermal conductor
Malleability	Excellent — easily pressed, rolled and formed
Strength	Low when pure; much stronger as an alloy
Machinability	Easy to cut and machine
Recyclability	100% recyclable; recycling uses only 5% of the energy of primary production

Uses: Drinks cans, kitchen foil, aircraft structures (as alloy), window frames, bicycle frames, cooking pots, electrical cables (overhead power lines).

Copper

Property	Detail
Colour	Distinctive reddish-orange; develops green patina (verdigris) over time
Conductivity	Best electrical conductor after silver; excellent thermal conductor
Malleability	Very malleable — easily formed into tubes, sheets and wire
Ductility	Very ductile — drawn into thin wire
Corrosion resistance	Good — tarnishes but does not rust
Antimicrobial	Naturally kills bacteria on contact
Cost	Moderately expensive

Uses: Electrical wiring, plumbing pipes and fittings, PCB tracks, roofing, decorative items, cookware bases, coins (as alloy).

Silver

Property	Detail
Colour	Bright, lustrous white
Conductivity	Highest electrical and thermal conductivity of any metal
Malleability	Excellent
Corrosion	Tarnishes (blackens) when exposed to sulphur compounds in air
Cost	Expensive (precious metal)

Uses: Jewellery, silverware, electronics (contacts, solder), photography (historically), antibacterial coatings.

AQA Exam Tip: You do not need to memorise every property of every metal, but you should know at least two key properties and two applications for each. Link properties to uses — e.g. copper's excellent conductivity makes it ideal for electrical wiring.

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Alloys

An alloy is a mixture of two or more metals (or a metal and a non-metal) to produce a material with improved properties compared to the individual metals.

Why Make Alloys?

Reason	Example
Increase strength	Pure aluminium is soft; adding copper, magnesium, etc. creates duralumin, which is much stronger
Increase hardness	Pure copper is soft; adding zinc creates brass, which is harder
Improve corrosion resistance	Adding chromium to iron creates stainless steel
Change colour / appearance	Adding zinc to copper changes the colour from red to gold (brass)
Lower melting point	Solder (tin + lead/other metals) melts at low temperatures for joining
Improve castability	Some alloys flow better when molten, filling moulds more completely

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Common Non-Ferrous Alloys

Brass