抄録
In order to clarify the mechanism of flaking which is generated on the race and bearing of the ceramics, rolling fatigue tests under lubricated ball-plate contact were carried out on the smooth HIP-Si_3N_4 race and the pre-cracked HIP-Si_3N_4 race, and the stress in the race were calculated using the expressions in terms of elementary function of spherical Hertzian contact by M. T. Hanson. As a result, it was found that the crack was initiated at the knoop indentation, and progressed by the maximum shear steres for the knoop race. Also, it was seen that the main crack that made the maximum principal stress to be driving force of the progress progressed along the trajectory of the minimum principal stress for the smooth and ring crack race.
