Structural and Tribiological Studies of MoS2 Solid Lubricant Films HavingTailored Metal-Multilayer Nanostructures

摘要

Molybdenum disulfide (MoS2) solid lubricant films were prepared by rf magnetronsputtering on 440C steel, 52100 steel, and Si substrates. This study concentrated on films that were multilayer coatings of MoS2 with either Ni or Au-Pd(20%) metal interlayers. Multilayer thickness ranged from 0.2 run to 1.0 run while the multilayer periodic spacing ranged from 3 to 10 run. Scanning electron microscopy and X-ray diffraction revealed that the multilayer films had dense microstructures that, in some cases, exhibited significant orientation of their basal planes parallel to the substrate. Film endurance was assessed in sliding contact by using thrust washer tests and in rolling contact by using thrust bearing tests. Some film microstructures exhibited excellent endurance. Brale indentation indicated that the metal layers can improve film fracture toughness. Friction in air and ultra-high vacuum (UHV) was investigated using a UHV-compatible test apparatus. Friction coefficients between 0.05 and 0.08 were measured in UHV.