Highly Oriented MoS2 Coatings: Tribology and Environmental Stability

• DOI: 10.1007/s11249-016-0745-0
• Publication Date: 2016-09-03T06:02:29Z
• Authors: John F. Curry; Nicolas Argibay; Tomas Babuska; Brendan Nation; Ashlie Martini; Nicholas C. Stran...; Michael T. Dugger; Brandon A. Krick
• Keywords: 02 engineering and technology; 0210 nano-technology

Molybdenum disulfide (MoS2) coatings have been prepared via nitrogen (N2) spray deposition, a process which deliberately impinges particulates of MoS2 onto a substrate yielding a preferential basally oriented state. Adherent and highly oriented 100- to 300-nm-thick coatings were produced. These coatings exhibited lower initial friction coefficients than sputtered films in dry and humid environments. Such reductions likely stem from a higher degree of basal plane orientation throughout the film as confirmed by XRD. Initial friction in humid air for sprayed coatings (µ = 0.10) was half that of sputtered coatings (µ = 0.21), showing the ability of oriented surface films to produce a low shear strength interface. Aging of these coatings in a humid nitrogen environment also showed the propensity for the films to resist poisoning of their structure which could otherwise result in degraded tribological performance. These results also support the hypothesis that water vapor does not contribute to the oxidation of MoS2.