Abstract
The influence of nano‐size WS2 powders on the tribological behavior of ta‐C coatings by the filtered cathodic vacuum arc (FCVA) method under boundary lubrication conditions has been investigated. In order to characterize and understand tribological behaviors of nano‐size WS2 powders added to the synthetic oil (poly‐alpha‐olefin 6), lubricants with different mixture ratios, ranging from 2 to 8 wt%, have been prepared. ta‐C coatings fabricated by FCVA method showed that the G‐peak in the obtained Raman spectrum was shifted from 1520 to 1586 cm−1, indicating the sp3 content increased for samples with the thickness of 156 nm. The average friction coefficient decreased proportionally as the nano‐size WS2 compositions increased up to 4 wt% in PAO6. After the friction test, structures and particle sizes of WS2 phases were also precisely characterized by using XRD and SEM.
Highlights
Various lubricants that contain nanometer sized solid lubricants have received a considerable attention recently due to their improved physical and chemical properties compared to bulk materials or individual molecules [1,2,3]
The object of this paper is to investigate the effect of nano-size WS2 additives on the lubrication performance of Xbend filtered ta-C coatings when rubbed against AISI 52100 depending on the load and the concentration of nano-size WS2 solid lubricants added to PAO6 under the boundary lubrication condition
XRD analysis recorded for PAO6 with 4 and 8 wt% WS2 is presented in Figure 2 showing sharp peaks indicating a high quality crystalline structure, with (002) as the strongest peak
Summary
Various lubricants that contain nanometer sized solid lubricants have received a considerable attention recently due to their improved physical and chemical properties compared to bulk materials or individual molecules [1,2,3]. Nanoparticles as additives in lubricating oils as cannot be retained by typical filters [5]. For those reasons, nanoparticle solid lubricants have been synthesized and successfully used in industries. The combination of nanometer sized solid lubricants and tetrahedral ta-C can improve the tribological performance in the rubbing state. An X-bend filter is known for a high plasma transmission efficiency, which leads to the reduced macro particle generation, improved deposition rate, and high quality ta-C films with 80% sp bonding. Tribological performance of ta-C coatings under lubricated conditions and their interaction with lubricating additives are strongly affected by the hydrogen content, chemical stability, sp2/sp ratio, and environmental conditions [10]. The object of this paper is to investigate the effect of nano-size WS2 additives on the lubrication performance of Xbend filtered ta-C coatings when rubbed against AISI 52100 depending on the load and the concentration of nano-size WS2 solid lubricants added to PAO6 under the boundary lubrication condition
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
