Shrouding Gas Plasma Deposition Technique for Developing Low-Friction, Wear-Resistant WS2-Zn Thin Films on Unfilled PEEK: The Relationship Between Process and Coating Properties

Research output: Contribution to journalArticleResearchpeer-review

Authors

  • Dietmar Kopp
  • Reinhard Kaindl
  • Thomas Prethaler
  • Anna Maria Coclite
  • Wolfgang Waldhauser

External Organisational units

  • Institute for Water Resources Management Hydrogeology and Geophysics
  • Technische Universität Graz

Abstract

In this study, tungsten disulfide–zinc (WS2-Zn) composite films were generated on polyether ether ketone (PEEK) disks by an atmospheric pressure plasma jet (APPJ) equipped with a shrouding attachment. The friction and wear properties of the WS2-Zn coatings were intensively investigated by using a rotational ball-on-disk setup under dry sliding and ambient room conditions. In order to gain more information about the lubrication mechanism, the coating areas as deposited and the worn areas (i.e., in the wear track) were analyzed with a scanning electron microscope (SEM) with regard to their chemical composition in depth by energy-dispersive X-ray spectroscopy (EDS). X-ray photoelectron spectroscopy (XPS) was conducted to obtain precise chemical information from the surface. The results indicated that WS2-Zn coatings significantly improved the tribological properties, exhibiting a coefficient of friction (COF) of <0.2. However, the tribological performance of the coatings is strongly dependent on the plasma process settings (i.e., plasma current, dwell time of the powder particles in the plasma jet), which were tuned to reduce the oxidation by-products of WS2 to a minimum. The COF values achieved of the dry lubricant films were significantly reduced in contrast to the uncoated PEEK by a factor of four.

Details

Original languageGerman
Article number1365
Number of pages18
JournalCoatings
Volume14.2024
Issue number11
DOIs
Publication statusPublished - 27 Oct 2024