Lubricated seizure of mild steel observed by X-ray imaging

Observation of frictional contacts has always been a problem as the contact is normally hidden. In this work, an X-ray microscope has been used for in situ observation of frictional seizure, wear and interfacial features duri ng the testing of mild steel specimens sliding against an Al alloy 6061 dis c. This technique enables the interfacial features of the hidden contact to be observed. Seizure tests were conducted at different sliding speeds of 2 , 4 and 5 m/s under lubricated conditions with plain mineral oil. The image s obtained during the tests indicated that the X-ray attenuation along its path increased with sliding at isolated locations, due possibly to localize d changes in path length or attenuation by the degraded mineral oil. The sl iding speed was found to have a considerable impact on the degradation of t he oil, which affected the seizure behaviour.