{{Short description|Graphite-based composite for ultra-high temperature applications}} [[Image:Impact-test.jpg|thumb|right|240px|Pieces of reinforced carbon–carbon including a panel removed from the wing of Space Shuttle ''Atlantis'',<ref>{{Cite web |url=http://www.swri.org/3pubs/ttoday/fall03/LeadingEdge.htm |title=On the Leading Edge |access-date=2012-05-06 |archive-date=2011-12-15 |archive-url=https://web.archive.org/web/20111215202959/http://swri.org/3pubs/ttoday/fall03/LeadingEdge.htm |url-status=live }}</ref> showing brittle failure of '''C/C''' due to foam impact reproducing a possible event during ''Columbia'''s final launch.]] '''Carbon fibre reinforced carbon'''{{#tag:ref| Variously hyphenated "carbon fibre reinforced carbon",<ref name="Kochendörfer">{{cite book |editor-last1=Singh |editor-first1=Mrityunjay|editor-last2=Jessen |editor-first2=Todd |issn=0196-6219 |chapter-url=https://books.google.com/books?id=8ZgXPpxbuTkC&pg=PA11 |access-date=7 September 2017 |date=2009-09-28 |publisher=John Wiley & Sons |isbn=9780470295144 |pages=11–22 |last=Kochendörfer |first=Richard |title=25th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings |chapter=Ceramic Matrix Composites - from Space to Earth: The Move from Prototype to Serial Production |volume=22 |orig-year=2001 |doi=10.1002/9780470294680.ch2|chapter-url-access=subscription }}</ref> "carbon-fibre-reinforced carbon",<ref>{{cite book |editor-last1=Clark|editor-first1=A. F.|editor-last2=Reed|editor-first2=Richard|editor-last3=Hartwig|editor-first3=Gunther|title=Nonmetallic Materials and Composites at Low Temperatures |chapter-url=https://books.google.com/books?id=0RPaBwAAQBAJ&pg=PA245 |access-date=7 September 2017|date=2012-12-06 |publisher=Springer Science & Business Media|isbn=9781461575221 |pages=245–266 : 245 |last1=Fritz|first1=W.|last2=Hüttner |first2=W. |last3=Hartwig |first3=G. |orig-year=1979 |series=Cryogenic Materials (CRYMS) |chapter=Carbon-Fibre-Reinforced Carbon Composites: Processing, Room Temperature Properties, and Expansion Behaviour at Low Temperatures |doi=10.1007/978-1-4615-7522-1_16}}</ref> or "carbon fibre-reinforced carbon";<ref name="Lewandowska">{{cite journal|last1=Lewandowska-Szumieł |first1=M |first2=J |last2=Komender |first3=A |last3=Gorecki |first4=M |last4=Kowalski|year=1997|journal=Journal of Materials Science: Materials in Medicine |title=Fixation of carbon fibre-reinforced carbon composite implanted into bone |volume=8|issue=8|pages=485–488 |issn=0957-4530 |doi=10.1023/A:1018526226382|pmid=15348714 |s2cid=26258090 }}</ref> while "carbon fibre" is also spelled "carbon fiber". |group="n"}} ('''CFRC),'''<ref name="Lewandowska"/> '''carbon–carbon''' ('''C/C),'''<ref name="Kochendörfer"/> or '''reinforced carbon–carbon''' ('''RCC''') is a composite material consisting of carbon fiber reinforcement in a matrix of graphite. It was developed for the reentry vehicles of intercontinental ballistic missiles, and is most widely known as the material for the nose cone and wing leading edges of the Space Shuttle orbiter. Carbon-carbon brake discs and brake pads have been the standard component of the brake systems of Formula One racing cars since the late 1970s; the first year carbon brakes were seen on a Formula One car was 1976.
Carbon–carbon is well-suited to structural applications at high temperatures, or where thermal shock resistance and/or a low coefficient of thermal expansion is needed. While it is less brittle than many other ceramics, it lacks impact resistance; Space Shuttle ''Columbia'' was destroyed during atmospheric re-entry after one of its RCC panels was broken by the impact of a piece of polyurethane foam insulation that broke off from the External Tank.
==Production==
The material is made in three stages:<ref name=":0">{{Cite web|url=http://edge.rit.edu/content/P07109/public/Design%20I/Published%20Research%20Documents/CARBON%20FIBER%20PROPERTIES.pdf|title=Carbon Fiber Properties|date=May 2004|website=Rochester Institute of Technology EDGE (Engineering Design Guide and Environment)|access-date=January 30, 2019|archive-date=February 8, 2023|archive-url=https://web.archive.org/web/20230208040456/http://edge.rit.edu/content/P07109/public/Design%20I/Published%20Research%20Documents/CARBON%20FIBER%20PROPERTIES.pdf|url-status=dead}}</ref>
First, material is laid up in its intended final shape, with carbon filament and/or cloth surrounded by an organic binder such as plastic or pitch. Often, coke or some other fine carbon aggregate is added to the binder mixture.
Second, the lay-up is heated, so that pyrolysis transforms the binder to relatively pure carbon. The binder loses volume in the process, causing voids to form; the addition of aggregate reduces this problem, but does not eliminate it.
Third, the voids are gradually filled by forcing a carbon-forming gas such as acetylene through the material at a high temperature, over the course of several days. This long heat treatment process also allows the carbon to form into larger graphite crystals, and is the major reason for the material's high cost. The gray "Reinforced Carbon–Carbon (RCC)" panels on the space shuttle's wing leading edges and nose cone cost NASA $100,000/sq ft to produce,{{clarify|date=April 2014}}<!-- so how big is the "panel" described? what is the cost per sq. meter of a certain thickness? or cost per kg of Carbon-Carbon material produced? or cost per unit volume of material? And, of course, need sources too. --> although much of this cost was a result of the advanced geometry and research costs associated with the panels. This stage can also include manufacturing of the finished product.<ref name=":0" />
C/C is a hard material that can be made highly resistant to thermal expansion, temperature gradients, and thermal cycling, depending on how the fiber scaffold is laid up and the quality/density of the matrix filler. Carbon–carbon materials retain their properties above 2000 °C. This temperature may be exceeded with the help of protective coatings to prevent oxidation.<ref>{{Cite web |url=http://www.makeitfrom.com/data/?material=Carbon-Carbon |title=Material Properties Data: Carbon–carbon |access-date=2010-03-06 |archive-date=2010-04-01 |archive-url=https://web.archive.org/web/20100401131419/http://www.makeitfrom.com/data/?material=Carbon-Carbon |url-status=live }}</ref> The material has a density between 1.6 and 1.98 g/cm<sup>3</sup>.<ref name="ias">{{cite journal|url=http://www.ias.ac.in/sadhana/Pdf2003Apr/Pe1069.pdf|date=24 April 2003|journal=Sādhanā|volume=28|pages=349–358|title=High performance carbon–carbon composites|author=LALIT M MANOCHA|issue=1–2|doi=10.1007/BF02717143|s2cid=123705345|access-date=2014-06-28|archive-date=2013-09-03|archive-url=https://web.archive.org/web/20130903021716/http://www.ias.ac.in/sadhana/Pdf2003Apr/Pe1069.pdf|url-status=live}}</ref>
==Similar products== [[File:Concorde_undercarriage_Speyer_02_with_disc_brakes.JPG|thumb|right|240px|The Dunlop carbon brakes as used on the Concorde airliner.]]
[[Image:Ferrari F430 Challenge Brake.JPG|thumb|right|240px|The brake disc of this Ferrari race car's braking system is made from carbon fibre-reinforced silicon carbide which is a CMC rather than a C/C]]
'''Carbon fibre-reinforced silicon carbide''' ('''C/SiC''') is a development of pure carbon–carbon that uses silicon carbide with carbon fibre. It is slightly denser than pure carbon-carbon and thought{{by who|date=July 2023}} to be more durable.
It can be used in the brake disc and brake pads of high-performance road cars. The first car to use it was the Mercedes-Benz C215 Coupe F1 edition.<ref>[http://www.supercars.net/cars/1229.html 2000 Mercedes-Benz CL55 AMG F1]</ref> It is standard on the Bugatti Veyron and many Bentleys, Ferraris, Lamborghinis, Porsches, and the Corvette ZR1 and Z06. They are also offered as an optional upgrade on certain high performance{{clarify|date=July 2023}} Audi cars, including the D3 S8, B7 RS4, C6 S6 and RS6, and the R8. The material is not used in Formula 1 because of its weight.{{citation needed|date=August 2025}}
Carbon brakes became widely available for commercial airplanes in the 1980s,<ref>[http://www.boeing.com/commercial/aeromagazine/articles/qtr_03_09/article_05_1.html Boeing: Operational Advantages of Carbon Brakes]</ref> having been first used on the Concorde supersonic transport.
A related non-ceramic carbon composite with uses in high-tech racing automotives is the carbotanium carbon–titanium composite used in the Zonda R and Huayra supercars made by the Italian motorcar company Pagani.
==Footnotes== {{reflist|group="n"}}
==References== {{reflist}}
==External links== *[http://www.flightglobal.com/pdfarchive/view/1971/1971%20-%202817.html ''Carbon brakes for Concorde'']
{{DEFAULTSORT:Reinforced Carbon-Carbon}} Category:Composite materials Category:Refractory materials Category:Fibre-reinforced polymers