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Si3N4/SiC composite ceramics were sintered and subjected to three-pointbending. A semi-elliptical surface crack of 100 μm in surface length was made on eachspecimen. The crack-healing behavior under cyclic stress of and resultant cyclic fatiguestrength at the healing temperature of 1100 ℃ and 1200 ℃ were systematicallyinvestigated. The main conclusions are as follows. (1) Si3N4/SiC composite ceramics havethe excellent ability to heal a crack at 1100℃ and 1200℃. (2) This sample can heal acrack even under cyclic stress at a frequency of 5 Hz. (3) The crack-healed sampleexhibited sufficient cyclic fatigue strength at the each crack-healed temperature, 1100 ℃and 1200 ℃.