Material Properties — Physical (AQA GCSE Design & Technology): Revision Note

Density

What is density?

• Density describes how heavy a material is relative to its size (mass and volume)

• High-density examples: steel, concrete, glass (heavy and strong)

• Low-density examples: foam, timber, polymers (lighter weight)

• High-density applications: tools, structures

• Low-density applications: packaging, sports equipment

Fusibility

What is fusibility?

• Fusibility describes how easily a material melts when heated

• High fusibility: melts easily at lower temperatures (e.g. thermoforming polymers, solder at 180–190°C)

• High fusibility applications: packaging, plastic bottles (recyclable)

• Low fusibility: difficult to melt, requires high temperatures (e.g. thermoset polymers, ceramics, steel)

• Low fusibility applications: heat-proof mats, car disc brakes, radiators

Electrical & thermal conductivity

What is electrical conductivity?

• Electrical conductivity describes how well electricity flows through a material

• Conductors allow good electricity flow (e.g. copper, aluminium, steel)

• Conductor applications: electrical wiring, circuit boards, plugs

• Insulators resist or stop electricity flow (e.g. polymers, rubbers, timbers, ceramics)

• Insulator applications: wiring insulation, plug housing, tool handles

What is thermal conductivity?

• Thermal conductivity describes how well heat flows through a material

• Thermal conductors allow good heat flow (e.g. copper, aluminium, steel)

• Conductor applications: cooking pans, radiators, heaters

• Thermal insulators resist or stop heat transfer (e.g. thermoset polymers, timbers, foams, ceramics)

• Insulator applications: tool handles, saucepan handles, kettle bodies, pipe insulation