OCR A-Level Product Design materials and their properties overview quiz quiz

A metal that contains iron as its main element, so it is usually magnetic and rusts

A metal that contains no iron at all, so it resists corrosion and never rusts in use

A mixture of two or more different metals melted and combined into a single alloy

A metal that can only ever be supplied to the workshop in the form of loose granules

Thermoplastics have permanent covalent cross-links between their chains, whereas thermosets are held only by weak intermolecular forces

Thermoplastics have weak intermolecular bonds that heat overcomes, while thermosets have covalent cross-links that heat cannot break

Thermosets contain no polymer chains at all, so there is simply nothing in them for heat to soften or move

Thermoplastics are always far stronger and stiffer than thermosets, so heat affects them much less easily

Oak

Pine

MDF

Mahogany

A coniferous (evergreen) tree

Any fast-growing tree

A tree grown only in plantations

A broadleaved (deciduous) tree

Absorb energy and resist impact without fracturing

Resist scratching and surface wear

Be drawn into a wire

Return to its original shape after a load is removed

270 kg per cubic metre

2700 kg per cubic metre

1080 kg per cubic metre

27000 kg per cubic metre

Hammered or rolled out flat into a thin sheet under a compressive force

Heated until it softens and then remoulded repeatedly into a new shape

Drawn out into a wire under tension without breaking

Scratched and worn away very easily by another harder material

Mild steel, a ferrous alloy of iron and carbon

Acrylic, a single thermoplastic polymer

Pine, a natural softwood timber from a conifer

Carbon-fibre reinforced polymer (CFRP)

Heat

Light

pH

Sound

Generates a small electric current whenever it is squeezed or mechanically deformed

Changes colour with temperature, giving the user visual feedback

Glows brightly in the dark after being charged up by exposure to ordinary light

Becomes much harder and stiffer the moment it is heated above room temperature

Thermochromic pigment

Shape memory alloy

Kevlar

Piezoelectric material

Injection moulding

Vacuum forming

Sintering

Extruded section

It needs less machining and produces less waste

It makes the finished material noticeably stronger and stiffer than it was before

It removes the need for any surface finishing or treatment on the finished part

It permanently changes the density of the material being used to make the part

Only the material's strength, since nothing else matters for a kettle body at all

Function, manufacturability at scale, cost and environmental impact together

Only the range of colours the material happens to be available in off the shelf

Only the raw material price per kilogram, ignoring every other factor entirely