Lubricity and Tribochemical Reactivity of Advanced Materials Under High Vacuum

The aim of this study was to develop and characterize advanced tribological materials for space applications. For this purpose a newly developed Ultra High Vacuum (UHV) tribometer CA3UHV was used to determine friction, wear and triboemission of gases and volatiles from atmospheric pressure down to high or ultrahigh vacuum. The study was focused on two classes of materials: a) advanced lubricants based on ionic liquids (ILs), b) engineered diamond-like carbon films as anti- wear and low-friction coatings. Tribochemical mechanisms were identified by analyzing gas triboemission involved in the generation of protective tribofilm layer and/or transfer film and surface chemical characterization.