Twin-disc tests in microelastohydrodynamic lubrication (micro-EHL) confirm that prior running-in at lower sliding speed enhances load and temperature at scuffing. Examination of surface oxidation and smoothing gives a new insight into the running-in process and suggests that the latter is the dominant effect. Restatement of the operating conditions in terms of non-dimensional groups that take into account the current roughness of the surfaces shows there to be little difference at scuffing.

No abstract