Fretting fatigue of ultrahigh-strength steels at very high numbers of load cycles

Friction fatigue is material damage caused by material surfaces moving against each other. Damage can be the formation of abrasion, the promotion of corrosion, the introduction of resulting surface stresses or microstructural changes in metastable phases. This favors the initiation of fatigue cracks and ultimately causes fracture in the contact area of the material surfaces moving relative to each other. Frictional fatigue occurs, for example, in pressed connections between axles and hubs in railroad carriages, in joint sockets of implants, between engine blades and disks, in rivets on airplanes or in camshafts of engines. The number of load cycles, i.e. the back and forth movements of the components pressed together, is very high and can be in the region of 100 million or more. To investigate the underlying fracture mechanisms, laboratory tests must be carried out up to this high number of load cycles, which takes a long time using conventional test methods. Friction fatigue at very high numbers of cycles is therefore poorly documented in the scientific literature. The scientific question of the project is the development of a method for high-frequency fretting fatigue and its application for testing ultra-high-strength steels. Translated with DeepL.com (free version)