Space shuttle, carbon composite

Historically, polymer-matrix composite materials such as boron-epoxy and graphite-epoxy first found favor in applications, followed by metal-matrix materials such as boron-aluminum. Ceramic-matrix and carbon-matrix materials are still under development at this writing, but carbon-matrix materials have been applied in the relatively limited areas of reentry vehicle nosetips, rocket nozzles, and the Space Shuttle since the early 1970s. 

What do bamboo stalks, mud bricks, steel-belted radial tires, fiberglass fishing rods, reinforced concrete, and the heat tiles on a space shuttle have in common The answer is that these materials are all composites. A composite is a material consisting of two or more components with overall properties different from and superior to either or any one of the individual components. For example, many pleasure boats today have hulls made of a composite material called reinforced plastic that contains glass, plastic, carbon, or some other type of fiber embedded in plastic. The composite material is stronger, more durable, and less dense than the fibers or plastics of which it is made. 

The performance of carbon/carbon composites became well known to the general public by the repeated successful landings of the American space shuttles, in which 2D carbon/carbon composites, reinforced two-dimensionally by a fiber web or fabric, are used for structural parts that are critical during reentry, such as the nose cap and the leading edges of the wings see Figure 1 (9 ) ... 

Figure 1. The leading edge (L.E.) of the wing and the nose cap of the COLUMBIA space shuttle (jj) are made of reinforced carbon composites (RCC) ...

For the purposes of this chapter, carbon/carbon (C/C) composites consist of carbon fiber preforms which are surrounded by a carbon matrix. Development of these materials began in the late 1950s, and was continued under a variety of U.S. Air Force, NASA, and other federal government programs.7 They currently find use in structures such as the space shuttle nose cone and leading edges, and brake materials, and have the potential to be used in many... 

Other forms of carbon-carbon composites have been or are being developed for space shuttle leading edges, nuclear fuel containers for satellites, aircraft engine adjustable exhaust nozzles, and the main structure for the proposed National Aerospace plane (34). For reusable applications, a silicon carbide [409-21-2] based coating is added to retard oxidation (35,36), with a boron [7440-42-8] based sublayer to seal any cracks that may form in the coating. 

The importance of carbon-fibre composite materials in the development of the space shuttle cannot be overemphasized. Reinforced carbon-carbon composites are used in the nose cone and wing leading edges to provide the resistance to thermal shock and stress required for re-entry into the Earth s atmosphere. Carbon-carbon composites are a particular group of carbon-fibre reinforced materials in which both the bulk material and fibres are carbon. The... 

The real development of carbon-earbon composites started in 1958, with US Air Force sponsored work, which later received a massive boost with the onset of the Space Shuttle Program. Carbon-carbon composites can be tailor-made to give a wide family of products by controlling the choice of fiber type, fiber presentation and matrix. 

These rayon-based carbon fabrics found Immediate success In the exit cone application as well as In heat shields. In subsequent developments, the phenolic resin matrix was Itself "carbonized and "graphltlzed to further enhance heat resistance capability and such "carbon-carbon" composites, containing rayon-based carbon fabrics, are found today on the nose and the wing leading edge of the space shuttle. 

Carbon-ceirbon composites for aircraft brakes and space shuttle components... 

Carbon-fiber composites are found in many new structural applications such as racing cars, fishing poles, tennis rackets, competition skis, and sailboat spars. However, their greatest impact is in the aerospace industry with applications in the space shuttle, advanced passenger airplanes, aircraft brakes, and many others. 

Due to the excellent high-temperature properties of ceramics, ceramic matrix composites are mainly used in aerospace industry and in power engineering. For example, components for gas turbines, rocket engines, or heat shields (e g., in the Space Shuttle) can be made of ceramic matrix composites. They may also be used in brake discs in aeroplanes or in upmarket cars. One example are the brake discs of the Boeing 767, manufactured from a carbon-carbon composite. Compared to a conventional brake disc, the mass could be reduced by almost 40% [28]. 

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