Aircraft ceramic applications

Despite this past downward trend, which has persisted in the United States since 1979 with modernization oflarge suppliers in Japan and Europe, growth of 2 to 2.5% is now expected into the mid-1990s. This reflects increased demand for some military applications and commercial aircraft, plus growing needs for farm and construction machinery (2). U.S. production of the relatively new ceramic ball bearings is expected to increase distinctively by about 50% yearly to reach 17 million in 1993 (3). 

Sintered Materials or Cermets. Heavy weights and high landing speeds of modem aircraft or high speed trains require friction materials that are extremely stable thermally. Organic or semimetallic friction materials are frequendy unsatisfactory for these applications. Cermet friction materials are metal-bonded ceramic compositions (see Composite materials) (12—14). The metal matrix may be copper or iron (15). 

Epoxy-phenolic adhesives were developed primarily for bonding metal joints in high-temperature applications. Their first major application was to join major aircraft components. They are also commonly used for bonding glass, ceramics, and phenolic composites. Because of their relatively good flow properties, epoxy phenolics are also used for bonding honeycomb sandwich composites. 

It is truly remarkable that catalysts can function so well in the exhaust of the modem highspeed vehicle. This fact has raised confidence in industry to use different monolithic (ceramic and metal) structures as supports for catalysts for other environmental applications such as diesel exhausts, power and chemical plants, restaurants, and even on widebody aircraft. 

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