Effect of relative slip amplitude on fretting fatigue behavior of silicon nitride

Fretting fatigue tests were carried out using HIP-sintered silicon nitride to study the effect of relative slip amplitude between the specimen and the contact pad on fretting fatigue behavior. Fretting fatigue strength decreased with increasing relative slip amplitude. Application of static contact without fretting motion had no influence on static fatigue strength. Therefore, fretting action with relative slip is essential for the degradation of fatigue strength. Fretting fatigue life prediction based on fracture mechanics analysis was also carried out, where the frictional force between the specimen and the contact pad was taken into consideration. The predicted fretting fatigue lives agreed well with the experimental results.