THE FRICTION AND WEAR OF CERAMIC-CERAMIC AND CERAMIC-METAL COMBINATIONS IN SLIDING CONTACT

The tribological characteristics of ceramics sliding on ceramics are c ompared to those of ceramics sliding on a nickel-based turbine alloy. The friction and wear of oxide ceramics and silicon-based ceramics in air at temperatures from room ambient to 900-degrees-C (in a few cases to 1200-degrees-C) were measured for a hemispherically-tipped pin on a flat sliding contact geometry. In general, especially at high temper ature, friction and wear were lower for ceramic/metal combinations tha n for ceramic/ceramic combinations. The better tribological performanc e for ceramic/metal combinations is attributed primarily to the lubric ious nature of the oxidized surface of the metal.