Ion-assisted deposition of silver films on ceramics for friction and wear control

Development and implementation of novel surface modification methods for controlling friction and wear of ceramic surfaces are of crucial importance to the success of ceramic tribosystems. Frictional heat, tribochemical interactions, and microfracture during sliding contact give rise to severe wear damage and frictional instabilities in tribosystems consisting of ceramic materials. This study introduces a new approach to surface modification involving ion-assisted deposition (IAD) of silver films on alumina and sapphire ceramics to achieve improved adhesion, friction, and wear behavior. The results of pin-on-disc experiments showed that silver films produced by IAD were very adherent and the wear rates of ceramic substrates coated with IAD silver were negligible. The friction coefficients of ceramic substrates were also substantially reduced by these silver films. Without ion assistance, silver films severely delaminated from the wear tracks of ceramic substrates and the wear rates and friction coefficients were relatively high. 23 refs., 7 figs., 1 tab.