An obvious requirement for any high performance-racing vehicle is that it should be strong and lightweight. For these reasons carbon fibre has been acknowledged as the best material for the job. The modern F1 car is based around the central monocoque, which protects the driver, and is the connection point for other components. This is the part of the car that is made from carbon fibre due its properties, of having a high tensile strength and high torsional rigidity. Carbon fibre is also flame proof, and when the car crashes it absorbs a huge amount of energy shattering the fibres and prevents the energy from transferring to the driver. This is what allows F1 drivers to walk away unscathed from horrific accidents.
Properties
They have a very low thermal expansion coefficient, making them dimensionally stable at a wide range of temperatures, and they have high thermal conductivity. Highly resistant to thermal shock and fractures due to temperature change.
However the main reason that makes carbon fibre desirable, is that it is strong, and extremely lightweight. This is what allows objects like rackets and clubs to hit ball with great force and power, and being lightweight makes it easy to do so.
Structure
Carbon fibres are polycrystalline and consist of a large number of small crystallites. They are made up of two-dimensional layers of carbon atoms as in the graphite structure and are about 10-8m thick and about 2.5 x 10-8m in diameter.
Then undirectional fibres, woven or knitted into a polymer matrix, usually in resin form; an example would be a thermosetting resin such as epoxy or maybe a thermoplastic such as PEEK.
While woven carbon fibre is available un-coated, the majority of carbon fibres have the polymer pre-coated. As they have been reinforced carbon fibres are thought of as a composite material, and this is what gives this material its strength but enables the product to remain lightweight.
How is it made?
Start off with a polymer called poly-acryloni-trile, we take this polymer and heat it up, as the thermal energy causes the cyano repeat units to form cycles
DIAGRAM ONE
Then the new product is heated again, but at a higher temperature, and the carbon atoms kick off their hydrogen, and the rings become aromatic. This polymer is a series of fused pyridine rings
DIAGRAM TWO
Then we have heat it again slowly roasting the polymer around 400-600 degrees centigrade, which will join the adjacent chains together
DIAGRAM THREE
This expels hydrogen gas, and gives us a ribbon like fused ring polymer. But again we have to crank up the heat anywhere from 600 to 1300 degrees centigrade.
DIAGRAM FOUR
The nitrogen is expelled as a gas, and the polymer formed has line of nitrogen atoms along its edge. These ribbons can again be heated to merge and remove the majority of nitrogen, leaving an almost pure carbon fibre.
Other Uses
It is the same, lightweight properties and high tensile strength that allow aircraft to utilise carbon fibre in designs for wings and engines, as the strength is the same as steel so reduces the overall mass of the planes saving fuel and increasing efficiency.
One of the more interesting uses is the use of Carbon fibre in musical instruments. MATIT is company in Finland, which has developed the first carbon fibre flute, made of a high modulus fibre that improves the acoustics of the instrument. They also are looking at using Carbon fibres in guitar strings.
Carbon fibres are widely used for scientific purposes and the most obvious seems to be use of carbon electrodes. It is known for single fibres to be used in neurology due to the diameter of each fibre being only 8 microns. They also can absorb poisonous gases so have military applications.
