Information AboutCarbon-carbon |
| CATEGORIES ABOUT REINFORCED CARBON-CARBON | |
| composite materials | |
| refractory materials | |
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Reinforced Carbon-Carbon ('''carbon-carbon''' or '''RCC''') is a Composite Material consisting of Carbon Fiber reinforcement in a matrix of Graphite , often with a Silicon Carbide coating to prevent oxidation. It was developed for the nose cones of Intercontinental Ballistic Missiles , and is most widely known as the material for the nose cone and Leading Edge s of the Space Shuttle . 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 after one of its RCC panels was broken by the impact of a piece of foam insulation from the Space Shuttle External Tank . This was a catastrophic failure partly because original shuttle design requirements did not consider such a violent impact to be likely. PRODUCTION The material is made in three stages: 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, so that voids 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. |
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