Factors Affecting the Tribological Performance of Three Resin Bonded Solid Lubricant Films

Abstract

A ball-on-disk adapter was employed to simulate the point contacts arising at the disk specimens with a thin layer of solid lubricant film. The disk specimens were prepared by various surface treatment methods on the substrates. Other factors affecting the properties of the lubricant films are the coating materials and the thickness of the solid lubricant films. These factors are believed to have an impact on the friction coefficient and are investigated from experiments. The experimental results reveal that the lowest friction coefficient exists in the film which is neither too thick nor too thin. The tests for the specimens with the molybdenum disulphide or the molybdenum disulphide+graphite film show that a film too thin or too thick isn't beneficial to the wear life. On the other hand, the coating film with the polytetrajluoroethylene shows the wear life is almost linearly proportional to the film thickness. For all three lubricant films, a higher friction coefficient is often accompanied with an elevation in wear coefficient. The specimens with the polytetrajluoroethylene film show the smallest friction coefficient and the lowest wear coefJicient among the three solid lubricants under the same load.

Surface Characterization of Three‐Layer Organic Coating Applied on AISI 4130 Steel

“…Values typically higher than 0.3 for Str mean a high isotropy of surfaces [17], which is the case of this surface. Lin and Yan Guu [7] identi ed only a slight increase in the surface roughness Ra when the shot-blasting process was applied onto a ground surface of the steel. ey could have given more attention for that point, once the use of shot blasting as the previous treatment for a MoS 2 deposition resulted in the lowest friction coe cient in a ball-on-disk testing apparatus, comparing it with other surface treatments (phosphatizing and salt-bath soft nitriding).…”

“…Lin and Yan Guu [7] evaluated only the bidimensional average roughness Ra for three primary processes (shot blasting, phosphatizing, and salt-bath soft nitriding) previously applied onto a ground surface of steel before the final treatment to obtain a topcoat of MoS 2 . In the same way, Roberts and Williams [8] investigated the effect of the surface roughness on the tribological performance of sputtered MoS 2 films, but their approach was again limited to two-dimensional characterization and restricted to the average roughness.…”