Abstract
To develope the design concept for a typically hard and brittle material of fine ceramics, its fatigue properties in static and cyclic loading conditions must be systematized especially from the reliability point of view. Though the number of papers on its fatigue behavior is not so many as compared with those on static strength or fracture toughness because of difficulty in conducting fatigue tests, the results obtained hitherto indicate that the scatter of fatigue life is very large presumably depending on the distribution of pre-existing defects. In order to evaluate the cyclic fatigue strength characteritics of fine ceramics systematically, a new pneumatic resonance type plane bending fatigue testing machine with a loading rate of about 80Hz was trially manufactured. With this testing machine, statistical fatigue tests were carried out by using sintered silicon nitride thin plate specimens of simple shape. Excellent performance of the testing machine was confirmed through the experiments, and the results indicate that the distribution of the fatigue lives obeys a 3-parameter Weibull distribution function.
