Abstract
Silicon nitride ceramics are superior in strength at high temperature, and apply to ceramic gas-turbines and fuel cells. However ceramics are brittle and sensitive to flaws. To overcome the sensitivity and improve the reliability of ceramics, we developed Si3N4-SiC composites which show excellent crack-healing ability.
The oxidation behavior of Si3N4-SiC composites having crack-healing ability was investigated and compared with heat-treatment conditions. The oxidation test was carried out at 1000°C for 500hr. The measurement of weight gain, bending strength, observation of oxidized surfaces were carried out.
The main results obtained are as follows: (1)The weight gain of Si3N4-SiC composites treated crack-healing was lower. (2)The bending strength of Si3N4-SiC composites increased the value after oxidation. (3)The crack healing conditions are useful for increasing the oxidation-resistance, and improving strength.
