Wear performance of ground nanostructured ceramic coatings

This study investigates the wear performance of ground nanostructured ceramic coatings. In this study, nanostructured Al2O3/13TiO2 coatings were ground under various conditions and subjected to wear tests under given speed and loading conditions. In the wear tests, a ground sample of cylindrical shape was mounted onto the spindle head of a vertical milling machine. The sample was rotated and slid/rolled against a flat Si3N4 ceramic wear bar that traveled back and forth. Wear tracks of the nanostructured ceramic coatings on the cylindrical surface were observed and measured with a scanning electron microscope and a surface profilometer. The result of wear performance of the nanostructured Al2O3/13TiO2 coatings was compared with that of their conventional counterparts. To further investigate wear mechanisms of the coatings, finite element method was used to model the stress fields in the sliding/rolling contact. The information on the stress fields should provide a clue to wear crack initiation and propagation within the coating. Discussion is provided on how the wear performance of the coatings is related to the grinding process parameters and to the grain size of the coating.