F-0211 電子顕微鏡によるセラミックス摩耗面の観察(S34-3 摩擦磨耗メカニズム)(S34 トライボロジー現象の新しい計測・観察法)

抄録

Wear mechanisms of ceramics are discussed based on the microstructural observations of the wear surface by electron microscopy. From room temperature to 600℃, little sign of deformation, such as dislocations and twins, was observed in the sliding wear surface of alumina. Above 800℃, extensive dislocations and twins were observed beneath the very fine grain size layer of the surface. This microstructure suggests that plastic deformation associated with dynamic recrystallization occurs during the high-temperature sliding which prevents brittle microfracture, thus resulting in a low wear rate. For the erosion surface of alumina, dislocations were consistently observed in the surface both at room and high temperatures. The dislocation density increased with increasing temperature, and therefore the erosion rate increased by dislocation-induced microfracture at grain boundaries.