Difference between revisions of "Carbon fibre"

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'''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.
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{{X}}
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<small>''Carbon fibre'' and ''[[Carbon fiber]]''</small>
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[[Image:Kohlenstofffasermatte.jpg|thumb|A cloth of woven carbon filaments]]
  
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It has many applications in [[aerospace]] and [[automotive]] fields, as well as in [[sailboats]], and notably in modern [[bicycle]]s,  where these qualities are of importance. It is becoming increasingly common in small consumer goods as well, such as [[laptop]]s, [[tripod]]s, and [[fishing rod]]s. 
 
  
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==Composite==
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'''Carbon fiber''' can refer to carbon filament thread, or to felt or woven cloth made from those carbon filaments. By extension, it is also used informally to mean any [[composite material]] made with carbon filament; for more on that application, see [[graphite-reinforced plastic]].
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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 [[moulding|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.  
 
  
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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.
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==Synthesis==
  
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The chemistry and manufacturing techniques for [[thermosetting plastic]]s 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]] [http://en.wikipedia.org/wiki/Joint_Strike_Fighter#Program__History competition] included a Delta-shaped carbon fibre reinforced thermoplastic wing, but difficulties in fabrication of this part contributed to [[Lockheed Martin]] winning the competition.
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Each [[carbon]] filament is made out of long, thin filaments of carbon sometimes transferred to [[graphite]]. A common method of making carbon filaments is the oxidation and thermal [[pyrolysis]] of [[polyacrylonitrile]] (PAN), a [[polymer]] used in the creation of many synthetic materials. Like all polymers, polyacrylonitrile molecules are long chains, which are aligned in the process of drawing continuous filaments. When heated in the correct conditions, these chains bond side-to-side (letter polymers), forming narrow [[graphene]] sheets which eventually merge to form a single, [[jelly roll]]-shaped or round filament.  The result is usually 93-95% carbon. Lower-quality fibre can be manufactured using [[Pitch (resin)|pitch]] or [[rayon]] as the precursor instead of PAN. The carbon can become further enhanced, as high modulus, or high strength carbon, by heat treatment processes. Carbon heated in the range of 1500-2000 °C (carbonization) exhibits the highest [[tensile strength]] (820,000 [[pound force per square inch|psi]] or 5,650 MPa or 5,650 N/mm²), while carbon fiber heated from 2500 to 3000 °C (graphitizing) exhibits a higher [[modulus of elasticity]] (77,000,000 psi or 531 GPa or 531 kN/mm²). For further literature see Rose, Ziegmann and Hillermeier.  
  
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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 edge]]s of the [[space shuttle]].
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==Textile==
  
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==Automotive uses==
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There are several categories of carbon fibers: standard modulus (240 GPa) , intermediate modulus (300 GPa), and high modulus (> 300 GPa). The tensile strength of different yarn types varies between 2000 and 7000 MPa. The density of carbon fiber is 1750 kg/m<sup>3</sup>.
  
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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.
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Precursors for carbon fibers are PAN, rayon and pitch. In former times rayon was more used as a precursor and still is for certain specialized applications (rockets). Carbon fiber filament yarns are used in several proccessing techniques: the direct uses are for prepregging, filament winding, pultrusion, weaving, braiding etc.
  
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Several [[supercar]]s 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]].
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These filaments are stranded into a yarn. Carbon fiber yarn is rated by the linear density (weight per unit length = 1 g/1000 m = tex) or by number of filaments per yarn count, in thousands. For example 200 tex for 3K (3,000 filaments) carbon fiber is 3 times as strong as 1K carbon fiber, but is also 3 times as heavy.  This thread can then be used to [[weave]] a carbon fiber filament [[Textile|fabric]] or [[cloth]]. The appearance of this fabric generally depends on the linear density of the yarn and the weave chosen.  Carbon fiber is naturally a glossy black but recently colored carbon fiber has become available.
  
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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.
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==Uses==
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Carbon fiber is most notably used to reinforce [[composite material]]s, particularly the class of materials known as [[carbon fiber reinforced plastic]]s.  This class of materials is used in aircraft parts, high-performance vehicles, sporting equipment, wind generator blades and gears and other demanding mechanical applications; a more thorough discussion of these uses, including composite lay-up techniques, can be found in the [[carbon fiber reinforced plastic]] article.
  
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[[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.
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Non-polymer materials can also be used as the matrix for carbon fibres.  Due to the formation of metal carbides (i.e., water-soluble [[aluminium carbide|AlC]]), bad [[wetting]] by some metals, and [[corrosion]] considerations, carbon has seen limited success in [[metal matrix composite]] applications; however, this can be improved by proper surface treatment, eg. for carbon-aluminium MMCs a [[vapor deposition]] of [[titanium boride]] on the fibers is often employed.  [[Reinforced carbon-carbon]] (RCC) consists of carbon fiber-reinforced graphite, and is used structurally in high-temperature applications, such as the nose cone and [[leading edge]]s of the [[space shuttle]].
  
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[[Chevrolet]] is already using carbon fiber in its flagship sports car, the [[Chevrolet_Corvette|Corvette]].  A special option package for the Corvette, dubbed the [[Chevrolet_Corvette#Z06_2|Z06]], includes carbon fiber front bodywork for reduced weight and added rigidity.
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The fiber also finds use in [[filtration]] of high-temperature gases, as an [[electrode]] with high surface area and impeccable [[corrosion]] resistance, and as an anti-[[Triboelectric effect|static]] component in high-performance clothing.
  
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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.
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Some [[string instrument]]s, such as [[violin]]s and [[cello]]s, use carbon fiber reinforced composite [[bow (music)|bows]]. This is an alternative to the more common wooden bows. There are also several companies which make entire instruments, such as cellos, out of carbon fiber.
  
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==Civil Engineering Applications==
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Many high-end frames for [[road bike]]s and [[mountain bike]]s are made of carbon fiber reinforced composite.  Also, many road bikes made of aluminum have carbon fiber reinforced composite seat posts, handlebars and forks for reduced weight and improved rider comfort.
  
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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 stress|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[http://www.abigroup.com.au/categoryProjects.asp?id_category=54&id_nav_parent=31]
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It is also widely used to enhance the look of automobiles and reduce weight. Many of the "[[car tuning|tuner]]" style cars have carbon fiber hoods to reduce weight from a stock 28 lb hood to an 8 lb hood. Another use is in the increasingly popular hobby of [[RC car]]s, many high-end kits come with many carbon fiber parts due to their light weight and attractive appearance.
  
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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.
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Carbon fiber is also used by [[skateboard]] companies to make strong lightweight skateboards for all types of skating, mainly downhill speedboarding. It is also used in many composite longboards to stiffen an otherwise very flexible board.
  
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== See also ==
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Carbon fiber is also used on racing [[yacht|yachts]], [[scull|rowing boats]], [[kayak|kayaks]] and [[sprint canoe|canoes]], as well as on the [[paddle|paddles]] and [[oar|oars]] used with them. Its use has allowed boat builders to produce stiffer and lighter boats.  Carbon, along with other artificial fibers, has replaced more traditional [[laminate|laminated]] [[wood|wooden]] or [[fiberglass]] constructions.
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*[[Carbon fiber]]
 
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*[[Graphite]]
 
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*[[Kevlar]]
 
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*[[Fibreglass]]
 
  
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== External links ==  
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==External links==
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*[http://www.societyofrobots.com/materials_carbonfiber.shtml Working with Carbon fibre for Robotics and R/C Aircraft]
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*[http://www.f1technical.net/articles/3 Carbon Fibre in Formula One]
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*[http://www.chm.bris.ac.uk/webprojects2002/mjames/homepage.html The Chemistry of Carbon Fibre]
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*[http://pslc.ws/macrog//carfsyn.htm Making Carbon Fibre]
  
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{{Commons|Carbon fibre}}
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*[http://www.carbonfibre.gr.jp/english/ Japan Carbon Fibre Manufacturers Association (English)]
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[[Category:Carbon forms]]
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*[http://www.psrc.usm.edu/macrog/carfib.htm Carbon fibre page from the Department of Polymer Science at USM]
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[[Category:Synthetic fibers]]
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*[http://www.germancarfans.com/News.cfm/NewsID/2030725.001 BMW's use of carbon fibre reinforced plastics]
 
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[[Category:Composite materials]]
 

Latest revision as of 13:23, 8 October 2009

Carbon fibre and Carbon fiber

A cloth of woven carbon filaments


Carbon fiber can refer to carbon filament thread, or to felt or woven cloth made from those carbon filaments. By extension, it is also used informally to mean any composite material made with carbon filament; for more on that application, see graphite-reinforced plastic.

Synthesis

Each carbon filament is made out of long, thin filaments of carbon sometimes transferred to graphite. A common method of making carbon filaments is the oxidation and thermal pyrolysis of polyacrylonitrile (PAN), a polymer used in the creation of many synthetic materials. Like all polymers, polyacrylonitrile molecules are long chains, which are aligned in the process of drawing continuous filaments. When heated in the correct conditions, these chains bond side-to-side (letter polymers), forming narrow graphene sheets which eventually merge to form a single, jelly roll-shaped or round filament. The result is usually 93-95% carbon. Lower-quality fibre can be manufactured using pitch or rayon as the precursor instead of PAN. The carbon can become further enhanced, as high modulus, or high strength carbon, by heat treatment processes. Carbon heated in the range of 1500-2000 °C (carbonization) exhibits the highest tensile strength (820,000 psi or 5,650 MPa or 5,650 N/mm²), while carbon fiber heated from 2500 to 3000 °C (graphitizing) exhibits a higher modulus of elasticity (77,000,000 psi or 531 GPa or 531 kN/mm²). For further literature see Rose, Ziegmann and Hillermeier.

Textile

There are several categories of carbon fibers: standard modulus (240 GPa) , intermediate modulus (300 GPa), and high modulus (> 300 GPa). The tensile strength of different yarn types varies between 2000 and 7000 MPa. The density of carbon fiber is 1750 kg/m3.

Precursors for carbon fibers are PAN, rayon and pitch. In former times rayon was more used as a precursor and still is for certain specialized applications (rockets). Carbon fiber filament yarns are used in several proccessing techniques: the direct uses are for prepregging, filament winding, pultrusion, weaving, braiding etc.

These filaments are stranded into a yarn. Carbon fiber yarn is rated by the linear density (weight per unit length = 1 g/1000 m = tex) or by number of filaments per yarn count, in thousands. For example 200 tex for 3K (3,000 filaments) carbon fiber is 3 times as strong as 1K carbon fiber, but is also 3 times as heavy. This thread can then be used to weave a carbon fiber filament fabric or cloth. The appearance of this fabric generally depends on the linear density of the yarn and the weave chosen. Carbon fiber is naturally a glossy black but recently colored carbon fiber has become available.

Uses

Carbon fiber is most notably used to reinforce composite materials, particularly the class of materials known as carbon fiber reinforced plastics. This class of materials is used in aircraft parts, high-performance vehicles, sporting equipment, wind generator blades and gears and other demanding mechanical applications; a more thorough discussion of these uses, including composite lay-up techniques, can be found in the carbon fiber reinforced plastic article.

Non-polymer materials can also be used as the matrix for carbon fibres. Due to the formation of metal carbides (i.e., water-soluble AlC), bad wetting by some metals, and corrosion considerations, carbon has seen limited success in metal matrix composite applications; however, this can be improved by proper surface treatment, eg. for carbon-aluminium MMCs a vapor deposition of titanium boride on the fibers is often employed. Reinforced carbon-carbon (RCC) consists of carbon fiber-reinforced graphite, and is used structurally in high-temperature applications, such as the nose cone and leading edges of the space shuttle.

The fiber also finds use in filtration of high-temperature gases, as an electrode with high surface area and impeccable corrosion resistance, and as an anti-static component in high-performance clothing.

Some string instruments, such as violins and cellos, use carbon fiber reinforced composite bows. This is an alternative to the more common wooden bows. There are also several companies which make entire instruments, such as cellos, out of carbon fiber.

Many high-end frames for road bikes and mountain bikes are made of carbon fiber reinforced composite. Also, many road bikes made of aluminum have carbon fiber reinforced composite seat posts, handlebars and forks for reduced weight and improved rider comfort.

It is also widely used to enhance the look of automobiles and reduce weight. Many of the "tuner" style cars have carbon fiber hoods to reduce weight from a stock 28 lb hood to an 8 lb hood. Another use is in the increasingly popular hobby of RC cars, many high-end kits come with many carbon fiber parts due to their light weight and attractive appearance.

Carbon fiber is also used by skateboard companies to make strong lightweight skateboards for all types of skating, mainly downhill speedboarding. It is also used in many composite longboards to stiffen an otherwise very flexible board.

Carbon fiber is also used on racing yachts, rowing boats, kayaks and canoes, as well as on the paddles and oars used with them. Its use has allowed boat builders to produce stiffer and lighter boats. Carbon, along with other artificial fibers, has replaced more traditional laminated wooden or fiberglass constructions.

External links

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