Abstract
High temperature strength, creep and creep-fatigue behavior were investigated in air for Al2O3, SiC and Si3N4 ceramics. The high temperature tensile strength was influenced by the existence of additives in ceramics. The tensile strength showed displacement rate dependence. In the creep-fatigue tests of Si3N4 at 1673K, not only hysteresis loops but also ratchetting behavior were observed in the stress-displacement curves. It seemed that the fracture occurred when the total plastic ratchetting deformation reached a constant value.
