Carbon fibre
Graphite-reinforced plastic or carbon fiber reinforced plastic (CFRP or CRP), is a strong, light and very expensive composite material or fibre reinforced plastic. Like glass-reinforced plastic, which is sometimes called fiberglass, the composite material is commonly referred to by the name of its reinforcing fibers (carbon fiber), an example of part-for-whole metonymy. The plastic is most often epoxy, but other plastics, like polyester or vinylester, are also sometimes used.
It has many applications in aerospace and automotive fields, as well as in sailboats, and notably in modern bicycles, where these qualities are of importance. It is becoming increasingly common in small consumer goods as well, such as laptops, tripods, and fishing rods.
Composite
The choice of matrix can have a profound effect on the properties of the finished composite. One common plastic for this application is graphite epoxy, and materials produced with this methodology are generically referred to as composites. The material is produced by layering sheets of carbon fibre cloth into a mould in the shape of the final product. The alignment and weave of the cloth fibres is important for the strength of the resulting material. In professional applications all air is evacuated from the mould, however in applications where cost is more important than structural rigidity, this step is skipped. The mould is then filled with epoxy and is heated or air cured. The resulting stiff panel will not corrode in water and is very strong, especially for its weight. If the mould contains air, small air bubbles will be present in the material, reducing strength. For hobby or custom applications the cloth can instead be draped over a mould, and the epoxy is "painted" over it, however because of the resulting lack of strength, this is usually only used for cosmetic details.
The high amount of (often manual) work required to manufacture composites has hitherto limited their use in applications where a high number of complicated parts is required.
The chemistry and manufacturing techniques for thermosetting plastics like epoxy are often poorly-suited to mass-production. One potentially cost-saving and performance-enhancing measure involves replacing the epoxy matrix with a thermoplastic material such as Nylon or polyketone. Boeing's entry in the Joint Strike Fighter competition included a Delta-shaped carbon fibre reinforced thermoplastic wing, but difficulties in fabrication of this part contributed to Lockheed Martin winning the competition.
Other materials can be used as the matrix for carbon fibres, as well. Due to the formation of metal carbides (i.e., water-soluble AlC) and corrosion considerations, carbon has seen limited success in metal matrix composite applications. Reinforced carbon-carbon (RCC) consists of carbon fibre-reinforced graphite, and is used structurally in high-temperature applications, such as the nose cone and leading edges of the space shuttle.
Automotive uses
Carbon fiber is used extensively in racing, most especially in Formula One and Indycar racing. The high cost of carbon fiber is mitigated by the material's unsurpassed strength-to-weight ratio, and low weight is essential for high-performance automobile racing.
Several supercars over the past few decades have used carbon fiber for various components. The most notable is the current holder of the World Speed Record, the Koenigsegg CCR. This supercar is made almost entirely of carbonfibre, even the monocoque. Other supercars that make significant use of the material include the McLaren F1, Bugatti EB110, Pagani Zonda, Ferrari Enzo and Porsche Carrera GT.
Until now, the material has had limited use in mass-produced cars because of the expense involved - in terms of materials, equipment and the relatively limited pool of individuals with expertise in working with it.
BMW has begun studying and creating methods of producing carbon fibre reinforced plastics in its Landshut plant. To make the roof of the BMW M3 CSL, 5 layers of carbon fibre cloth are placed in an 1,800 ton press, where epoxy is resin transfer moulded and heat-cured in a robot-automated process. The resulting roof is half the weight of the equivalent steel roof.
Chevrolet is already using carbon fiber in its flagship sports car, the Corvette. A special option package for the Corvette, dubbed the Z06, includes carbon fiber front bodywork for reduced weight and added rigidity.
Use of the material has been more readily adopted by low-volume manufacturers like TVR who use it primarily for creating body-panels for some of their high-end cars due to its increased strength and decreased weight compared with the glass-reinforced plastic they use for the majority of their products.
Civil Engineering Applications
CFRP has recently become somewhat of a hot topic in the field of Structural Engineering, surprisingly enough, due to cost-effectiveness. Think for example, of a bridge. Many small bridges in the world were built quite a number of years ago, some actually dating to the era of horse-drawn carts. These bridges were designed to tolerate far lower service loads then they are subject to today. So compared with the cost of replacing the bridge, reinforcing it with CFRP is quite cheap. Due to the incredible stiffness of carbon fibre, it can be used underneath spans to help prevent excessive deflections, or wrapped around beams to limit shear stresses etc. The Westgate Bridge in Melbourne, for example, is as of 2005, the largest bridge in the world to be reinforced with carbon fibre laminates[1]
Much research is also now being done using CFRP as internal reinforcement in concrete structures, such as beams and bridge decks. The material has many advantages over conventional steel, mainly that it is much stiffer and corrosion resistant. There is, however, some hesitation among the engineering community in implementing these new materials, as more real-world evaluation must be done.