The influence of ring crack location on the rolling contact fatigue failure of lubricated silicon nitride: experimental studies

This paper presents an experimental study of the influences of ring crack location within the contact path on the rolling contact fatigue failure. The rolling contact tests are performed on silicon nitride/steel elements. Silicon nitride ball surfaces are examined before testing using a dye-penetrant technique and light microscopy. The surfaces during testing, post-test and after failure are examined using light microscopy. Research shows that fatigue failure under rolling contact loading is markedly sensitive to the location of ring crack on the contact track. Only a few locations on the contact track can lead to fatigue failure at the maximum Hertz contact pressure of 5.58 GPa.