Materials & manufacture · National 5
Metals
7 cards · 5 quiz · 1 exam
Design & Manufacture · National 5 · mrkellydt.co.uk
What you're learning in this topic
Learning intention WALT
We are learning about metals, specifically to understand:
- ferrous, non-ferrous and alloy
- the properties and uses of iron, cast iron, mild steel and stainless steel
- the properties and uses of high-carbon steel
- the properties and uses of aluminium, copper and brass
Success criteria WILF
- I can explain ferrous, non-ferrous and alloy
- I can describe the properties and uses of iron, cast iron, mild steel and stainless steel
- I can describe the properties and uses of high-carbon steel
- I can describe the properties and uses of aluminium, copper and brass
Ferrous and non-ferrous
- Ferrous: contain iron, attracted to magnets (except stainless steel), rust unless protected.
- Non-ferrous: no iron, not magnetic, form a dense oxide layer (tarnish) that slows further corrosion.
- Alloy: a mixture of a metal with other elements to improve properties (brass = copper + zinc; stainless steel = steel + chromium).
Metals you need to know
| Metal | Properties | Uses |
|---|---|---|
| Iron (wrought) | Soft, tough, malleable, can be forged; rusts | Decorative gates, railings, ornamental work |
| Cast iron | Brittle, casts well, can't be bent; painted to stop rust | Baths, benches, pans, weights |
| Mild steel | Ductile, malleable, easy to weld, rusts | Car bodies, nuts, bolts, screws |
| High-carbon steel (N5) | Can be hardened and tempered | Cutting tools, files, saws, taps and dies |
| Stainless steel | Hard, tough, corrosion and wear resistant, hygienic | Cutlery, sinks, pans, kitchen appliances |
| Aluminium | Light, good strength-to-weight, conducts heat/electricity, corrosion resistant | Cans, foil, ladders, aircraft, sports equipment |
| Copper | Tough, ductile, excellent conductor, solders well | Wires, pipes, circuit boards |
| Brass | Rigid, casts and polishes well, corrosion resistant | Taps, plaques, door fittings, instruments |
Exam link: answering a material question
State the property, then say why the product needs it. For a camping kettle in aluminium:
- Lightweight, so the kettle is easy to carry when camping.
- Good conductor of heat, so the water boils quickly.
- Corrosion resistant, so it will not rust when wet.
"Strong" or "light" with no link to the product is not awarded.
Key terms
| Ferrous metal | Contains iron; magnetic (except stainless); rusts. |
|---|---|
| Alloy | A metal mixed with other elements to improve its properties. |
| Mild steel | Ductile, malleable, easily welded. Car bodies, nuts and bolts. |
| Stainless steel | Corrosion resistant and hygienic. Cutlery, sinks. |
| Aluminium | Lightweight with good strength-to-weight ratio. Cans, ladders, aircraft. |
| Brass | Copper + zinc alloy: polishes well, corrosion resistant. Taps, fittings. |
| Copper | Excellent electrical conductor. Wires, pipes. |
Quick check
1. Which metal is ferrous?
- Mild steel
- Brass
- Aluminium
- Copper
Show answer
A: Mild steel. Steel is mostly iron.
2. Brass is an alloy of copper and…
- Tin
- Zinc
- Iron
- Aluminium
Show answer
B: Zinc. Copper + zinc.
3. Which metal suits kitchen cutlery?
- Mild steel
- Cast iron
- Stainless steel
- Copper
Show answer
C: Stainless steel. Corrosion resistant and hygienic.
4. Why is aluminium used for drinks cans?
- It is magnetic, so cans are easy to sort
- It is hard and stiff, so cans keep their shape
- It is the cheapest metal available
- Lightweight and corrosion resistant
Show answer
D: Lightweight and corrosion resistant. Light and does not rust.
5. Cast iron is unsuitable for a product that must bend because it is…
- Brittle
- Ductile
- Malleable
- Lightweight
Show answer
A: Brittle. Brittle materials snap rather than bend.
Exam-style questions
1. The frame of an outdoor bench is stainless steel. Explain why this is suitable. (2 marks)
Show marking guidance
- Corrosion resistant so it will not rust outdoors (1)
- Strong/tough so it supports the users' weight (1)
- Attractive finish needing little maintenance (1)
Printable worksheet
An I do, we do, you do worksheet for this topic, with a separate answer sheet.