Materials and Their Properties
The main categories of material and what makes each suitable for a job: timbers, metals, polymers, papers and textiles, their properties, and how a designer selects the right one.
Justify the choices, the way you are assessed
Free interactive practice on the decisions the assessment actually asks you to justify.
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Choosing the right material
Everything a designer makes is built from materials, and each material behaves differently, so choosing the right one is a core skill. Materials fall into main categories: papers and boards; timbers, which are either natural woods or manufactured boards; metals, which are ferrous if they contain iron and non-ferrous if they do not; polymers, which are the plastics; and textiles. Each material has properties, from how strong or hard it is to whether it rusts or conducts heat. Some polymers can be reheated and reshaped again and again, while others set hard for good. There are also smart materials that respond to their surroundings and composites that combine materials for extra strength. This module covers the categories of material, their properties, and how a designer selects the best material for a purpose.
Materials words
Learn what each of these means before you use it.
Thermoforming against thermosetting
Polymers split into two groups, and the difference is what happens when you heat them.
How to select a material
Choosing a material is not about a favourite; it is about matching properties to a job. Work in steps. First, ask what the product must do and the conditions it will face: will it be knocked, bent, heated, or left outdoors. Second, list the properties those conditions demand, such as strength, hardness or resistance to rust. Third, compare the possible materials against that list and pick the one that fits best, taking the cost and how easy it is to work into account too. A saucepan handle, for instance, needs to resist heat and not carry it to the hand, which points to a particular kind of material. Match properties to purpose, and any choice can be justified.
Match the material to what it is
- a hardwood such as oak
- a non-ferrous metal such as aluminium
- a thermoforming polymer such as acrylic
- a composite such as carbon fibre
- a strong, slow-grown natural timber
- a metal that contains no iron and does not rust
- a plastic that can be reheated and reshaped
- two materials combined for extra strength
Ferrous or non-ferrous?
A metal contains iron and will rust if it is left out in the rain. What kind of metal is it?
- a ferrous metal, because it contains iron
- a non-ferrous metal, because it does not contain iron
- a polymer, because it rusts
- a composite, because it is a metal
Working properties
Select the TWO working properties a material can have.
- Strength, resisting a force without breaking
- Hardness, resisting scratches and wear
- The price printed on the label
- The name of the shop that sold it
Counting the categories
Materials are grouped into 5 main categories: papers and boards, timbers, metals, polymers and textiles. A lesson has covered 3 of them. Subtract to find how many categories are left.
Order the material choice
Put these steps of choosing a material for a product in a sensible order.
- Decide what the product must do and where it will be used
- List the properties the product needs
- Compare materials against that list
- Choose the material that best fits
Complete the materials facts
A metal that contains iron and can rust is a _____ metal. A plastic that can be reheated and reshaped is a _____ polymer. A strong, slow-grown natural timber, such as oak, is a _____. Two or more materials combined to give better properties form a _____.
Match the property to its meaning
- strength
- hardness
- toughness
- malleability
- resists a pulling or pushing force without breaking
- resists scratching and surface wear
- resists sudden knocks without shattering
- can be shaped or bent without cracking
Spot the true materials facts
Tap the TWO statements that are true.
- A non-ferrous metal does not contain iron
- A thermosetting polymer cannot be reheated and reshaped
- A hardwood is a type of metal
- A composite is made from a single material only
Select for the job
Read each case and choose the best response, with a reason.
- A designer needs a metal for an outdoor gate that must not rust. Which should they choose?
- A product must be moulded once and then keep its shape even when it gets hot. Which polymer fits?
- A designer wants a material that is very strong but also very light for a racing bike frame. Which fits best?
Explain materials and properties
A friend is starting Design and Technology and asks how designers choose the right material. Explain materials and their properties.
- Name three categories of material and give an example of each
- Explain the difference between a ferrous and a non-ferrous metal
- Explain the difference between a thermoforming and a thermosetting polymer
- Explain two working properties a material can have
- Finish by explaining how a designer selects a material for a purpose