ABSTRACT
The chemistry involved in tribological interactions of two rubbing solids is complicated [1,2]. Mechanical contact, deformation, and shear at the interface create dynamic and often chemically reactive conditions for the atoms at the surface and within the subsurface [1]. Unless tribological contacts are made in ultra-high vacuum (UHV) conditions with no molecules adsorbed on the surface, or in ultra-high purity gases with absolutely no reactive impurities, there always will be third “chemical” components involved in the tribology in addition to the two sliding and countersliding solid surfaces. These third components can drastically alter the tribological responses of the solid interfaces. Those are the molecules impinging onto the solid surface from the surrounding space. If a liquid lubricant is utilized to mitigate the
7.1 Introduction ................................................................................................... 153 7.2 Survey of Environmental Effects in Tribology ............................................. 156
7.2.1 Metals ............................................................................................... 156 7.2.2 Ceramics ........................................................................................... 162 7.2.3 Carbon Surfaces ................................................................................ 165 7.2.4 Solid Lubricants ................................................................................ 168
7.3 Effects of Alcohol and Water Vapor on Adhesion, Friction, and Wear of Silicon Oxide ................................................................................................ 168 7.3.1 Capillary Adhesion ........................................................................... 169 7.3.2 Mitigating Friction and Preventing Wear of SiO2 in the Presence
of Alcohol Vapor ............................................................................... 176 7.3.3 Tribochemical Reactions of Alcohol on SiO2 Surfaces .................... 178
7.4 Lubrication Using Environmental Effects .................................................... 182 7.5 Concluding Remarks and Future Prospects .................................................. 184 Acknowledgments .................................................................................................. 184 References .............................................................................................................. 185
friction and wear problems between two solid contacts, then it is obvious that the tribological interface consists of three components; that is, solid--liquid--solid. Even if there is no liquid lubricant added to the system, there are always molecules adsorbed onto the solid surface from the gas phase that act as a third tribological component.
