Applications of carbon based nano-particles to space and aeronautics lubrication

At The National Aeronautics and Space Administration Glenn Research Center we have active tribology programs for aeronautics and space applications involving carbon based nano-particles. The conditions for application are considerably different for aeronautics and space applications ranging from high temperature atmospheric to ambient vacuum. Some of the lubricants and surface coatings of tribological significance that we have evaluated include neat carbon based nano-particles, both grown in situ and as bulk material deposited on the substrate, and dispersed in oils. These applications prove to be highly substrate dependent. The substrates we have considered for tribological couples include 440C stainless steel (SS), specialty alloys such as Inconel 718, quartz, silicon carbide and silicon nitride coupled to similar material, one of the other substrates listed or eutectic ceramics. In this presentation we will discuss results of our testing these systems in spiral orbit tribometers (SOT), in unidirectional pin-on-disc (PoD) tribometers and in pin-on-flat fretting tribometers.