Abstract
For space mechanical components, the characteristics of silver thin film dispersed nano-cluster diamond powder as a solid lubricant film had been investigated. The silver films dispersed the cluster diamond powder were made on the 440C stainless steel disks under vacuum of 3×(10)^<-2>Pa at 1080K without graphitization of the nano-cluster diamond powder. Frictional characteristics of the films were investigated by a pin-on-disk friction test in injected nitrogen gas atmosphere (30%RH, 15% oxygen gas) and under ultra high vacuum of 2×(10)^<-6>Pa. Initial Hertzian contact pressure was set almost 0.7GPa. The sliding speed between the pin and the disk was about 30mm/s. Compared with ion-plated silver film, the lifetime of the film dispersed the nano-cluster diamond powder was 100 times longer in nitrogen gas atmosphere. The initial friction coefficient showed 0.2,and then it showed stable 0.4 for a while. The cluster diamond powder is considered to prevent the wear of the silver film.
