Composite
materials
A composite material is more than one material which is
combined together to make a property. They are usually different elements;
physical and chemical properties that make up the composite material.
Advantages
The advantages of using composite materials is that it is
safe because fibres that are used to make the materials have a low electrical
conductivity and are efficient fire retardants so that they don’t react as
quick.
Composite materials have good strength because it is made up
of multiple layers therefore it can withstand more pressure applied. They are
made as strong as materials like aluminium and steel. They use a lot of fibres
and fillers within each layer so that they reduce the impact done to the
material.
Light weight- Composites are weighed less because they are
made up of different thin layers. It is said they are 25% less than steel and
30% lighter than aluminium. Light composite are used for vehicles and
aeroplanes. The Boeing 787 is a typical example which uses 50% composite
materials for the weight of it.
Durable- It is very durable because it is made up from more
than one layer that is stacked up upon each other. This is helpful as it makes
products that use composite materials last longer.
Particle based
composites
Tarmac –properties–used for Bike wheels, Cars wheels and
road surfacing.-Characteristics – An Asphalt concrete, made up of multiple
layers of minerals and asphalt, broken stone made with tar.
Concretes – properties – Buildings, bridges and paths.
Characteristics – A solid material – very versatile – strength, durability and
has a good thermal mass (Reduces the heat moving past the concrete.)
Cermets – properties Watches and circular power saw blades. –
Cermets can be made out of ceramic and metal material. Characteristics-High
temperature resistance and hardness, made out of ceramic and metal materials
which are combined together.
Board composites
Hardboard - Used for clipboards, furniture and benches.
Chipboard- Used for flooring, furniture and wardrobes.
Plywood -Used for seats, desks and housing e.g.: Ceiling.
Fibre composites
Natural wood – Used for toilet seats, drawers, for building
support.
Elastomers mixed with fibre- Used for grip on shoes, tires, and
springs on bicycles
Concretes mixed with fibres- Chair legs, basements and
flooring.
How does the
structure of plywood give material strength?
Plywood as a high density strength because it is a composite
material made up by gluing woods that can be softwoods and hardwoods. The more
layers and the more glue applied, the more strength Plywood will have as it
will start to become more resistant if lots of different layers are being used.
MDF (Medium
Density Fibreboard)
MDF is a wood product which is produced by the breaking down
of softwoods and hardwoods into small fibres of wood. It is made up of all
types of different fibre board. Sawdust can create MDF as when it is sawdust,
it is all combined together with glue and then hardened to gives the physical
properties of MDF. MDF can be used for worktops, draws and chairs.