Design & Technology

Materials

The material types used in D&T Resistant Materials are woods, metals, plastics, ceramics and composites. Each of these has its own characteristic working properties such as strength, malleability, conductivity, toughness and durability.

Types of materials

You need to be familiar with the different properties of ferrous and non-ferrous metals; softwood and hardwood timbers; and thermoplastics and thermoset plastics.

When working with resistant materials you need to be able to choose the best material for a job. Wood, metal and plastics are the most common materials used, followed by composites [composites: a complex material made of two or more distinct substances ] and ceramics.

The main classification of materials is given in the chart below. You need to know these terms and their definitions.

Material classification diagram

Plastics

Plasics are divided into thermoset plastics and thermoplastics. The main difference between the two is that thermoplastics can be heated and shaped many times, while thermoset plastics can only be heated and shaped once.

Composite materials

Composite materials are formed by combining and bonding two or more materials - a reinforcing material and a bonding agent such as glue. MDF [MDF: Medium-density fibreboard - a type of engineered wood made of compressed wood and fibre particles held together with glue ] and GRP [GRP: Glass-reinforced plastic - a strong and versatile material made by combining a plastic (usually polyester resin) with fibres made of glass ] are examples of composite materials. NB alloys [alloys: mixtures of two or more metals, or of a metal with a non-metal such as carbon. ] are not composite materials.

Metals

Metals can be either ferrous or non-ferrous. Ferrous metals contain iron while non-ferrous metals do not.

Both ferrous and non-ferrous metals are divided into pure metals and alloys. A pure metal is…