What is a material?
A material is any substance that has a name
examples: chalk, paper, wood, iron, air, water, clay, plastic, rubber, stone, leather, wax
Eveything is made up of materials
When we want to make something we need to chose the best material for the job.
In order to do this we need to know the properties of the material.
Properties of materials
A property of a material is something about it that we can measure, see or feel
Examples of different properties
Strong |
Weak |
Heavy |
Light in weight |
Rough |
Smooth |
Shiny |
Dull |
Hard |
Soft |
Flexible |
Brittle |
Magnetic |
Non-magnetic |
Transparent |
Opaque |
Absorbent |
Waterproof |
Conduct electricity |
Electrical insulator |
Conductor of heat |
Thermal (heat) insulator |
Burns when heated |
Does not burn |
Melts easily |
Does not melt easily
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Different objects are made out of different materials.
We need to chose the material with best properties for the job.
Example: Looking at the different materials in a bicycle
The saddle is covered in leather or thin plastic The tyre needs to grip the road, be flexible and easily moulded so rubber is the best choice . The frame needs to be strong and rigid so we chose a metal. Which metal we chose depends on how much we want to pay Blue = object Do you know which metals are usually used? |
Metals that can be used to make a bicycle frame Iron. The cheaper bicycles use iron. Iron is strong but is also heavy and rusts easily. The frame will usually be painted to stop it going rusty. Aluminium. Aluminium is much lighter than iron but is also more expensive. It does not rust so does not need to be painted. It is not as strong as iron so an aluminium frame is usually thicker. Tungsten Much stronger than aluminium but lighter than iron. It also does not rust. Very expensive! Carbon fibre. This is a very modern material and is not a metal at all. |
Materials can be placed into groups:
Metals | Shiny, conduct electricity and heat, strong, often heavy | Girders, Bicycle frames, Electric wires, Tools, Saucepans and good quality cuttlery. |
Ceramics | Substances made from pottery. They have been ‘fired’ at some stage in their manufacture. They look attractive, do not burn or melt but are usually brittle and break easily |
Tiles, kitchen plates, good quality cups |
Plastics | Plastics usually melt or burn easily,. They are not very strong but can easily made into different shapes. They arecheap to produce and are good electrical insulators |
Washing up bowls, covering to electric wire, plugs, cheap cuttlery, containers for food |
Glass | :Glass looks attractive and can eaily be made into different shapes. Transparent, Is not effected by liquids. Brittle but hard. (Breaks easily but will not easily scratch) |
Windows, mirrors, glasses, bottles |
Wood | Cuts easily and can be polished so it is shiny. Looks attractive |
Furniture, building materials |