Composite materials

Composite materials are made up of different materials which are combined to improve their properties. They can be a combination of natural and synthetic materials but fall into three main categories:

Fibre-based composites

Fibre-based composites are reinforced with fibres. By mixing resin or concrete with fibres of glass or carbon we get the ability to mould complex shapes, but reinforcing them with the fibres makes them very strong.

Fibre-based compositeMaterialsUses
Glass-reinforced plastic (GRP)Glass fibres and resinBoats, instrument cases
Carbon-reinforced plastic (CRP)Carbon fibre and resinFormula 1 car bodies, crash helmets, sports equipment
Glass-reinforced concrete (GRC)Glass fibre and concreteStreet furniture, urban features
Carbon-reinforced plastic (CRP) mudguard parts for automobiles sit on a table.

Carbon-reinforced plastic (CRP) in automobile parts

Particle-based composites

Particle-based composites are made with small particles of material. By mixing smaller particles of sand with larger particles of cement and aggregate, such as stones, we get a very strong and dense material suitable for building large structures.

Particle-based compositeMaterialsUses
ConcreteCement, sand and aggregateBuildings, street furniture
CermetCeramic (cer) and metal (met)Electronic components that need to operate under very hot temperatures
A close-up image of concrete being poured to construct floors of a building.
Concrete used in construction

Sheet-based composites

Sheet-based composites are often available in large sheets. By mixing wood fibres or thin slices of wood veneers with resin it is possible to form large and stable sheets for furniture panels and interior construction.

Sheet-based compositeMaterialsUses
Medium-density fibreboard (MDF)Wood pulp and resinFurniture and interior cladding
PlywoodWood veneers and resinFurniture and construction
ChipboardWood chip and resinFurniture panels and construction
A stack of three pieces of light plywood boards.
Plywood boards

Like all modern materials, composites are engineered to improve their properties. There are many more combinations of materials that are designed to meet a particular need or purpose. For example, wood has been reinforced with strips of carbon to make a wooden bicycle frame.

Often the original material has a useful feature, the ability to be formed or a certain appearance, but lacks strength or durability. In this case different material combinations can solve the problem and new composites are being developed all the time.