Abstract
This study describes the correlation between microstructure, mechanical and tribological properties of TiCx coatings (with x being in the range of 0-1.4), deposited by reactive magnetron sputtering from a Ti target in Ar/C2H2 mixtures at ~ 200 °C. The mechanical and tribological properties were found to strongly depend on the chemical composition and the microstructure present. Very dense structures and high hardness, combined with low wear rates and friction coefficients, were observed for coatings with chemical composition close to TiC. X-ray diffraction and X-ray photoelectron spectroscopy analysis, used to evaluate coating microstructure, composition and relative phase fraction, showed that low carbon contents in the coatings lead to sub-stoichiometric nanocrystalline TiCx coatings being deposited, whilst higher carbon contents gave rise to dual phase nanocomposite coatings consisting of stoichiometric TiC nanocrystallites and free amorphous carbon. Optimum performance was observed for nanocomposite TiC1.1 coatings, comprised of nanocrystalline nc-TiC (with an average grain size of ~ 15 nm) separated by 2-3 monolayers of an amorphous a-DLC matrix phase.
Original language | British English |
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Pages (from-to) | 2054-2061 |
Number of pages | 8 |
Journal | Diamond and Related Materials |
Volume | 17 |
Issue number | 12 |
DOIs | |
State | Published - Dec 2008 |
Keywords
- Diamond-like carbon
- Nanocrystalline
- Sputtering
- Tribology