Abstract
Cyclic fatigue crack growth behavior in Si_3N_4 was investigated using a small bending specimen with a micro notch. The micro notch was introduced by a Focused Ion Beam device. The bending fatigue tests were carried out under constant amplitude load at stress ratio R=-1. Fatigue crack growth rate and macroscopic crack closure were measured by means of an unloading elastic compliance method. It was found that the crack growth rate of a small crack was faster than that of a long crack due to the immaturity of grain interlocking.
