Friction and Wear of Solid Materials Sliding in Ultrahigh Vacuum and Controlled, Gaseous Environments

摘要

Sliding studies on additional synthetic layer lattic compounds have confirmed high friction in ultrahigh vacuum. However, the synthetic selenides studied could not be lubricated by long chain alcohols as was the case for synthetic sulfides. An analysis of the friction data for molydbenite in the presence of NH3 indicates that the step-wise rise in friction with increasing partial pressure is probably related to multilayer absorption phenomena. The changes in friction when the system is pressurized with N2 in the presence of either NH3 or O2 are probably related to the formation of mixed monolayers at the sliding interface. Wear rates of molybdenite pellets have been monitored continuously. Wear rates are highest at the lowest sliding speeds, and the wear rate increases faster than the first power of the normal load as other variables are held constant. (Author)