抄録
A mullite/SiC composite ceramic was sintered. Four point bend tests were conducted according to JIS standard. Semi-elliptical surface crack of 100 or 200μm in diameter was made on the specimen. For four kinds of specimens (asreceived, heal treated, pre-cracked and heal treated cracked), crack healing behavior and high temperature strength were tested systematically. The main conclusions were obtained as follows: (a) Mullite/SiC composite ceramic has ability to heal crack. (b) Best healing condition was found to be 1300°C, in air for 1h. (c) Maximum crack size to be healed is semi-elliptical crack of 100μm in diameter. (d) Crack healed part has enough strength up to 1100°C and most specimen failed outside the pre-cracked zone and healed crack is not sensitive to static fatigue.
