Effect of Modulation Periods on the Mechanical and Tribological Performance of MoS2–TiL/MoS2–TiH Multilayer Coatings

Abstract

MoS2–Ti coating is a widely used solid lubricant owing to its low friction coefficient. The mechanical and tribological performance of the coating can be further improved via introducing a multilayer structure, which is closely related to the modulation period and significantly affects the properties of the coating. Herein, the effect of two different modulation periods on the mechanical and tribological performance of the MoS2–TiL/MoS2–TiH multilayer coatings (where L and H represent low and high-powered sputtering of the titanium target) was studied. The performance of the coatings was found to depend on modulation periods of single layer thickness and thickness ratio, respectively. When the thickness ratio of MoS2–TiL layer to MoS2–TiH layer was fixed with different number of layers, the adverse effects of the interface outweighed the beneficial effect; thus, the mechanical and tribological performance of the multilayer coatings were improved with an increase in the single layer thickness. When the effect of the multilayer interfaces on the studied coatings was similar with the same number of layers, the MoS2–TiH layer had more impact on the hardness of the MoS2–TiL/MoS2–TiH multilayer coatings, whereas the MoS2–TiL layer substantially affected the adhesion properties, friction behavior and wear resistance. This study can provide a way to regulate coatings with different performance requirements via building different multilayer microstructures.

Solid Lubrication System and Its Plasma Surface Engineering: A Review

“…The layers consist of S-Mo-S three-atomic-layer structures held together by weak van der Waals forces between the layers [194,[218][219][220]. In the occurrence of sliding, the crystalline layers of MoS2 will easily slide and orient parallel to the direction of relative movement, which provides the lubricating effect [209,[221][222][223]. On the other hand, the solid ionic bond between S and Mo provides the lamellae a high resistance to asperities penetration.…”