Abstract
Surface crack growth behavior and flaking failure of Si_3N_4 ball bearings were investigated under rolling contact fatigue (RCF). Tests were carried out by using a thrust-type RCF machine. Small surface cracks and large surface cracks were made by using a Vicker's indenter and their lengths were measured during the tests. Their growth behavior was compared. It was found that the large cracks stably grew and that the small cracks initially grew but stopped growing after a certain number of cycles. The flaking failure occurred from the large surface cracks. It was discovered that the flaking failure was caused by subsurface cracks branched from the surface cracks.
