Various ongoing aerospace programmes call for development of improved materials capable of withstanding extremely high temperatures, having comparatively low density and high wear resistance. Several advanced materials like intermetallics, metal matrix composites (MMCs), ceramic matrix composites (CMCs) and carbon-carbon composites (C-CCs) are emerging to meet these challenges. The propulsion system is another vital area in which C-CCs find important applications. By making valves and tubings of C-CCs/carbon-ceramic composites, it has been possible to use propellants well beyond 2000 deg C, thus improving the specific impulse considerably. C-CCs have comparatively low densitycombined with very high-temperature capability. Its typical applications include aircraft brakes, ablativbe structures, rocket nozzles, engine parts, missiles, aerospace vehicles, thermal protection systems, satellites, racing car clutch, radio-antenna reflector panels, fire suppression, IR suppression shroud, avionics laser protection for compartment doors and internal shielding, radar absorbent material (RAM), ramjet combustor, heat pipes for space radiators, etc. Related to the theme of this conference is also the development of fullerenes, discovered only a few years ago. Unlike graphite or diamond, the fullerenes do not have a single structure but a family of molecular, geodesic structures in the form of cage-like spheroids. The unique features of fullerene molecules enable them to spin at a very high rate unrestrained. Its use in several fields is envisaged such as semiconductors, superconductors, non-metallic ferromagnetic materials, gas storage and gas separation, purification of natural gas, fuel cells and hydrogen storage, lubricants, microchips, electromechanical devices, sensors, diamond fibres and storage for radioactive isotopes.
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