Resum
Nanostructured coatings with variable contents of tungsten carbide (WC) and amorphous carbon (a-C) are prepared by controlling the sputtering power ratio using WC and graphite targets. XRD and TEM/ED analysis shows that increasing the C incorporation, the WC nanocrystalline phases evolve from γ-W2C to β-WC1.x. Further C enrichment leads to a nanocomposite structure of small WC1-x crystals dispersed in a-C matrix. The a-C at.% is estimated by XPS analysis and correlated with the observed tribo-mechanical properties. The hardness and friction properties vary from hard/high friction (36-40GPa; μ=0.6-0.8) to moderate-hard/low friction (16-20GPa; μ~0.2) coatings depending on the film composition. The transition point is found for a-C content of 10at.%. This correlates with a change from nanocrystalline WC to nanocomposite WC1-x/a-C coatings. The overall study will help to understand the previous literature data and will serve as guide for a tailored synthesis of these WC/a-C nanocomposites.
Idioma original | Anglès |
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Pàgines (de-a) | 3490-3500 |
Nombre de pàgines | 11 |
Revista | Surface and Coatings Technology |
Volum | 204 |
Número | 21-22 |
DOIs | |
Estat de la publicació | Publicada - d’ag. 2010 |
Publicat externament | Sí |