Lubrication of Si_3N_4 and Al_2O_3 in water with and without addition of silane coupling agents in the range of 0.05-0.10 mol/l

摘要

To improve water lubrication of ceramics at a lower sliding velocity, the effect of the addition of silane coupling agents was investigated. Si_3N_4 and Al_2O_3 were slid against themselves in water with and without 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 groups were effective in reducing the friction of Si_3N_4 and Al_2O_3 in water. Si_3N_4 also showed significant wear reduction but not Al_2O_3. However, the addition of a silane coupling agent containing an epoxy group increased both friction and wear of Si_3N_4. Improved lubricative characteristics of Si_3N_4 in water and in silane coupling agent solutions were obtained when Si_3N_4 contained smaller amounts of sintering additives. The adsorption behaviour of a silane coupling agent on ceramics was examined using both Fourier transform infrared spectroscopy and thin layer chromatography to clarify the interaction between the silane coupling agent and the ceramics. The role of polysiloxane film formation on ceramics is discussed to demonstrate the lubrication properties of ceramics.