Effectof shot peening factors on fretting fatigue resistance titanium alloy

The effects of the three factors, i.e., compressive residual stress (CRS), surface roughness (SR) and micro-structure hardening in shot peened (SP) surface on fretting fatigue (FF) resistance were evaluated. The mechanisms of SP on FF were investigated. The experimental results show that the compressive residual stress and surface roughness are predominant factors in improving FF resistance of Ti alloy, and CRS plays more important role than SR which decreases decaying of CRS. Compressive residual stress induced by SP arrests the crack into closure and slow growth. When the contact stress plays a dominant role in FF, the crack propagation controls FF process and the effect of CRS is more remarkable than other factors of SP.