Changes in Microstructure and Properties of ZnO-Added Al₂O₃ upon Sliding

Abstract

The changes in microstructure and properties of ZnO-added alumina upon sliding under water lubrication were studied. Although the frictional force was lower than that of conventional alumina in the early stages, it increased upon long-term friction testing. Of the acicular ZnO-nAl₂O₃ (n=3-9) and granular ZnAl₂O₄ phases dispersed in the samples, ZnAl₂O₄ with its low hardness was worn preferentially and pulled out during testing. The increase of frictional force during the sliding process was attributed to the pull-out of ZnAl₂O₄ particles and their traction on the sliding surface during the experiment.