High-Vacuum Tribometers: State of the Art and Current Developments

This paper reviews the application to tribology research of the techniques of high-vacuum surface science, in particular their integration into high-vacuum tribometers. The state of the art, the varied research interests, and the rationale for requiring such research instruments are discussed. The authors have developed a new type of high-vacuum tribometer that is aimed to the detection and characterization of charged-particle triboemission. This tribometer has been successfully used to count triboemitted charges as channel-electron-multiplier pulses and their energy distribution from different material pairs (i.e., ceramics and semiconductors when scratched by a diamond pin, and ceramics-on-same-ceramics). Instrument enhancement is ongoing to include simultaneous under-vacuum photon counting and surface work-function measurement by Kelvin-probe. The enhanced facility will enable one-of-a-kind experiments by characterizations and correlations of electron and photon emission, and of surface property evolution dynamics during sliding contact.