Rolling Contact Fatigue of Hot-Pressed Sialon Balls

The rolling contact fatigue life, reliability and failure mode of Sialon balls were examined through the rolling contact fatigue tests of the hybrid thrust bearing consisting of hot-pressed Sialon balls and bearing steel SUJ2 races. The rolling contact fatigue life of the Sialon balls was complied with the three-parameter Weibull distribution. In case of the smallest balls, the surface of which exhibits micro flaking with increasing the number of cycles, the shape parameter was relatively small and the fatigue life was comparatively dispersed. The rolling contact fatigue life might be influenced by the defects at the surface layer. The average value of the maximum flaking depths lay between the depth of the maximum value of the orthogonal shear stress τ_yz and the depth of maximum value of the maximum shear stress τ45-.