Summary. There is direct link between non-idealities in fretting wear, friction and fretting fatigue, especially in the case of adhesion spots. Friction is not a constant and varies as a function of load cycles and non-Coulomb friction may occur. Fretting wear may lead to material transfer, resulting in tangential fretting scar interactions, and in the long run, wear debris is entrapped and cumulated in the interface. Fatigue failure can occur at low nominal stress amplitudes due to nonCoulomb effects. Novel tools are required in component design to fully capture these non-ideal phenomena.Key words: fretting, friction, fretting wear, fretting fatigue
DescriptionFretting stands for the action of small amplitude reciprocating surface sliding, causing fretting wear and fretting fatigue. Slip amplitude is orders of magnitude smaller than the size of the contact, especially in engineering applications where large flat-on-flat contacts are common and sliding is typically undesired condition. The appearance and severity of fretting fatigue is dependent on stress field but also essentially on tribological features, such as friction and wear, which may generate surface micro-cracks and accelerate the initial stages of fatigue. Damage may appear below the pure fatigue based stress limits inside the contact that cannot be inspected visually without opening the joint [2,14]. Modelling of contacts is largely based on simple assumptions considering friction, wear and geometry [11].This study investigates fretting induced non-idealities in wear, friction and fatigue cracking, observed with quenched and tempered steel specimens in self contact (34CrNiMo6+QT, abbreviated as QT-steel). Result obtained using three different kinds of fretting apparatuses with different contact and loading types [4,5,8,9].