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Sputter deposited nanostructured Au-WS2 solid lubricant coatings

IR@NAL: CSIR-National Aerospace Laboratories, Bangalore

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Title Sputter deposited nanostructured Au-WS2 solid lubricant coatings
 
Creator Deepthi, B
Srinivas, G
Praveen, Kumar
Sridhara Rao, DV
Barshilia, Harish C
 
Subject Chemistry and Materials (General)
 
Description Au-WS2 nanocomposite coatings with approximately 60 at.% Au were prepared using magnetron sputtering from high purity Au and WS2 targets. Structural characterization of the coatings using X-ray diffraction indicated the presence of (111), (200) and (220) peaks of cubic Au and broad bands corresponding to (002) and (004) planes of hexagonal WS2. Surface morphology of Au-WS2 coatings was studied using field emission scanning electron microscopy (FESEM) and atomic force microscopy which showed formation of uniformly distributed interconnected ligament-like features. High resolution transmission electron microscopy studies showed the presence of a two phase nanocomposite structure wherein nanocrystalline Au was dispersed in a matrix of nanocrystalline and amorphous WS2. The electrical resistivity of Au-WS2 coating measured using four-point-probe method was approximately 0.2 μΩm compared to Au and WS2 coatings which exhibited electrical resistivity values of approximately 0.04 μΩm and 0.057 Ωm, respectively. Ball-on-disc reciprocating tests at a load of 7 N showed that Au-WS2 nanocomposite coating exhibited a friction coefficient of 0.22 after 57,600 cycles and outperformed Au and WS2 coatings. Analyses of the ball and wear track of Au-WS2 coating using FESEM at the end of the wear test indicated formation of smooth transfer films, less accumulation of wear debris and reduced oxidation.
 
Publisher American Scientific Publishers
 
Date 2012
 
Type Journal Article
PeerReviewed
 
Relation http://dx.doi.org/10.1166/nnl.2012.1274
http://nal-ir.nal.res.in/11478/
 
Identifier Deepthi, B and Srinivas, G and Praveen, Kumar and Sridhara Rao, DV and Barshilia, Harish C (2012) Sputter deposited nanostructured Au-WS2 solid lubricant coatings. Nanoscience and Nanotechnology letters, 4 . p. 53. ISSN 1941-4900