Development of Al2O3 based ceramics for dry friction systems

Increasing requirements for friction systems such as smaller dimensions and greater power transmission lead to enhanced power density in dry frictional contact. Present organic based materials will be overloaded due to severe conditions and new friction materials are needed maybe on the basis of advanced ceramics. In the present study, ceramic composites were produced by embedding TiN particles into the surface of a commercial monolithic Al2O3 ceramic using a laser-assisted process. In this way multiphase microstructures were achieved in a surface layer of about 300 μm thickness. Tribological performance of the ceramic composites was studied in a pellet-on-disc tribometer by running consecutive short-time tests as function of the counterbody material, sliding speed, humidity and temperature. The results showed a substantially improved stability of friction coefficient compared with the monolithic alumina used for reference.