Characterization of fretting fatigue damage by SEM analysis

Since the earliest studies of fretting fatigue were initiated surface damage and debris produced during the process have been of particular concern. The Scanning Electron Microscope (SEM) has proven to be a useful tool in the analysis of fretting damage mechanisms and their relationship to the degradation of fatigue properties. Results of analysis performed on fatigue specimens which have undergone simultaneous fretting damage and fatigue are presented.The results show that irreparable damage was not produced during the first fatigue cycles. Damage also was classified as initial or advanced by characteristic debris and surface appearance. Fretting damage produced at high fatigue stress was found to be similar in appearance to damage produced at low fatigue stress. Details of the damage and its relationship to the fretting process are discussed in the paper in some depth.