LUBRICATION OF SI3N4 AND AL2O3 IN WATER WITH AND WITHOUT ADDITION OF SILANE COUPLING AGENTS IN THE RANGE OF 0.05-0.10 MOL L/

To improve water lubrication of ceramics at a lower sliding velocity, the effect of the addition of silane coupling agents was investigated. Si3N4 and Al2O3 were slid against themselves in water with and withou t the addition of silane coupling agents in amounts ranging from 0.05 to 0.10 mol/l. Silane coupling agents containing one or more amino gro ups were effective in reducing the friction of Si3N4 and Al2O3 in wate r. Si3N4 also showed significant wear reduction but not Al2O3. However , the addition of a silane coupling agent containing an epoxy group in creased both friction and wear of Si3N4. Improved lubricative characte ristics of Si3N4 in water and in silane coupling agent solutions were obtained when Si3N4 contained smaller amounts of sintering additives. The adsorption behaviour of a silane coupling agent on ceramics was ex amined using both Fourier transform infrared spectroscopy and thin lay er chromatography to clarify the interaction between the silane coupli ng agent and the ceramics. The role of polysiloxane film formation on ceramics is discussed to demonstrate the lubrication properties of cer amics.