The Effect of PVD Tungsten-Based Coatings on Improvement of Hardness and Wear Resistance

Abstract:

This article deals with the analysis and evaluation of coatings applications made by Physical vapour deposition on ceramics substrates. Main focus is on the application of tungsten and tungsten nitride coatings for functionally graded materials (FGM). The article focuses on analysis and evaluation of tungsten and tungsten nitride coatings with ceramics substrates. Firstly suitable deposition parameters of W and WN coatings, prepared by magnetron sputtering, were tested. Test coatings on tool steel substrate exhibited high adhesion and good mechanical and technological properties. Both tungsten and tungsten nitride coatings on selected ceramics substrates exhibited good mechanical a technological properties. Properties such as hardness, reduced elastic modulus and wear are discussed for each coating/substrate combination. Both coatings seem to be good candidates for application in field of FGM. The results of the presented experiment shows that the adhesion and the final quality of the coating depends on the type of chemical bond in the coating and in the substrate, and on the ability of the coating to deform plastically.

• Periodical: Key Engineering Materials (Volume 606)
• Pages: 163-166
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.606.163
• Online since: March 2014
• Authors: Jakub Horník, David Tondl, Pavel Sachr, Evgenyi Anisimov, Maxim Puchnin, Tomáš Chráska
• Keywords: Adhesion, Nanoindentation, PVD, Scratchtest, Tungsten

References

[11] This is very promising especially for applications like milling in aggressive environment. Conclusions From presented measurements following conclusions could be made: Both coatings (W, WN) are considered as a suitable for the FGM with a sharp phase boundary. Especially suitable substrates for these coating are: homogeneous substrates, substrates with low hardness or wear resistance. In other cases (hard substrates like WC+Co) there were only minor improvement but other advantages could be reached (like higher resistance to high temperature corrosion etc. ), but these properties were not studied in presented work. 1) Pure tungsten could be considered as coating with high toughness decreasing crack growth between layer interfaces. Since its ability of increasing hardness or wear resistance were negligible in all studied cases. 2) Tungsten nitride could be considered as high strength and abrasion resistant coating improving the surface properties, since tungsten nitride coat improved hardness and wear resistance, in the majority of cases. 3) The adhesion dependence on chemical bond (coating and the substrate) and the plastic properties of coatings was observed. Adhesion seamed to decrease in systems with high bonding energy of the substrate. Acknowledgement Research was supported by Czech Science Foundation grant P108/12/1872. Literature.

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