Abstract: Friction and wear of alumina ceramics were conducted in dry sliding from room temperatureto 1200℃. Both friction and wear decreased obviously over 600℃. The friction coefficient at1200℃ was only 60% as that at room temperature. The specific wear rate at 1200℃ decreasedtwo orders of magnitude than that at 600℃, down to 5×10^-16m³/(N.m). There are three modelsof wear mechanism in the temperature range. Before 600℃, abrasive wear and development ofmicrocracks are the dominating mechanism. Between 600℃ and 1000℃, a amooth surface layer with very fine grains, similar to the structure of nano-ceramics, was formed. Plastic deformation and recrystallization controls the friction and wear. At 1200℃, a glassy film occurred on the surface by the severe plastic deformation, which makes the friction be in hydro-dynamic lubrication.

Key words: alumina ceramics, friction, wear, plastic deformation, self-lubrication, high temperature