Crack-Healing Behaviour of Zirconia/SiC Composite Ceramics
Keiji HOUJOU, Kotoji ANDO, Koji TAKAHASHI
Abstract:ZrO2/SiC composite ceramics were sintered and subjected to three-point bending. A surface crack of 100μm in diameter was made on each specimen. We studied crack-healing behavior. The main conclusions are as follows. (1) ZrO2/SiC composite ceramics could heal a crack. Then the best healing condition is 800°C×30h in air. (2) A crack was healed even at 600℃, which was a very low temperature compared with other ceramics. (3) The ZrO2/Y2O3/SiC system ceramics caused an extensive corrosion at over 1000°C. (4) Healing temperature and the minimum -time to heal were in the good proportional relation on the Arrhenius diagram at 600-800°C. Key Words:Ceramics, Zirconia, Crack healing, SiC-composite, Bending -strength, Arrhenius