In situ observation of cavitation in crossed microchannels

Tribological research often aims at extending the period of usage and at saving resources by the improvement of the frictional behaviour of contacts. Microtexturing of a functional surface can be an efficient tool for this purpose. In this work the influence of channel-like microtexturing on the tribological behaviour of a textured steel/sapphire contact was investigated in oil-lubricated sliding contact. Under insufficient lubrication bubbly flow structures appeared to be in the micro channels. Cavitation and other possible reasons for their appearance and the correlation with tribological measurements are discussed. A simplified CFD model is used to qualitatively support the results of the observations. Such phenomena could be important factors in applications with high sliding velocities and insufficient lubrication where heat transfer mechanisms in the channels are of great importance.