0
Research Papers

Microtribological Behavior of W-S-C Films Deposited by Different Sputtering Procedures

[+] Author and Article Information
C. Tomastik

e-mail: tomastik@ac2t.at

A. Pauschitz

Austrian Centre of Competence for Tribology,
Viktor-Kaplan-Strasse 2,
Wiener Neustadt, 2700, Austria

M. Roy

Defence Metallurgical Research Laboratory,
PO Kanchanbagh,
Hyderabad, 500 058, India

1Corresponding author.

Contributed by the Tribology Division of ASME for publication in the JOURNAL OF TRIBOLOGY. Manuscript received January 30, 2012; final manuscript received July 24, 2012; published online December 20, 2012. Assoc. Editor: Hong Liang.

J. Tribol 135(1), 011001 (Dec 20, 2012) (9 pages) Paper No: TRIB-12-1017; doi: 10.1115/1.4007537 History: Received January 30, 2012; Revised July 24, 2012

Tungsten sulfide is a transition metal dichalcogenide (TMD) with excellent self-lubricating properties, and a potential candidate for coatings for MEMS applications. Its mechanical and tribological properties can be further improved by alloying it with carbon (W-S-C films). These films are commonly manufactured by sputter deposition. The present work investigates the influence of sputtering procedure on the microtribological performance of W-S-C films. For this purpose, carbon was incorporated in the films via three different ways: (1) by using a reactive gas (CH4); (2) by co-sputtering from two separate targets (WS2 and C); and (3) by sputtering from a composite target of graphite embedded with WS2 pellets. The films were characterized with scanning electron microscopy (SEM), nanoindentation, atomic force microscopy (AFM), and micro-Raman spectroscopy (RS). Reciprocating wear tests were performed on a microtribometer with steel balls as counterbodies. The worn surfaces were investigated with white light confocal microscopy, RS, and X-ray photoelectron spectroscopy (XPS). The results show that the total wear decreases with the hardness of the investigated films and increases with applied load of the tribological test. The friction coefficient at higher load is governed by the roughness of the films. At low load, the presence of graphitic carbon determines the friction coefficient. No transfer of material from the counteracting body is observed.

FIGURES IN THIS ARTICLE
<>
© 2013 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Raman spectra obtained from the investigated films

Grahic Jump Location
Fig. 2

Deflection of the AFM cantilever tip as a function of the distance from the film surface for all three films: (a) reactively sputtered film, (b) film obtained by co-sputtering two targets, and (c) film obtained by sputtering a composite target

Grahic Jump Location
Fig. 3

The variation of the friction coefficient as a function of the number of cycles for all three films at different applied loads: (a) applied load = 200 mN, (b) applied load = 50 mN, and (c) applied load = 25 mN

Grahic Jump Location
Fig. 4

Topographic images obtained by white light confocal microscopy of the investigated films: (a) reactively sputtered film, (b) film obtained by co-sputtering two targets, and (c) film obtained by sputtering a composite target

Grahic Jump Location
Fig. 5

Total wear of the investigated films at different loads

Grahic Jump Location
Fig. 6

Topographic images obtained using SPM from the worn surfaces of the investigated films: (a) reactively sputtered film, (b) film obtained by co-sputtering two targets, and (c) film obtained by sputtering a composite target

Grahic Jump Location
Fig. 7

Raman spectra obtained from the worn surfaces of the investigated films

Grahic Jump Location
Fig. 8

XPS survey spectra obtained from the worn surfaces of the investigated films

Grahic Jump Location
Fig. 9

XPS detail spectra of S, C, O, and W from the worn surface of the reactively sputtered film

Grahic Jump Location
Fig. 10

Load dependence of the friction force for the films under microtribological test conditions

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In