Microstructure and friction behaviour in nanocrystalline diamond films

Abstract

In this study, friction behaviour of as-deposited and N⁺ ion-implanted nanocrystalline diamond films was investigated. In as-deposited film, the friction coefficient in ambient and humid condition was 0.8. Such a high value is explained by the formation of strong bonds across the sliding interfaces. In contrast, under similar test condition, friction coefficient of N⁺ ion-implanted film was ~0.07. The significant decrease in friction coefficient is ascribed to the formation of covalent CN_x phase which limits the formation of strong bonds in sliding interfaces.

Keywords:

• nanocrystalline diamond films
• tribological properties
• chemical passivation

Acknowledgements

The authors would like to sincerely thank Ms S. Kalavathi for XRD, Dr S. Dhara for Raman spectroscopy, Dr R. Subasri for contact angle measurement, Mr P. Maudapathy for N⁺ ion implantation and Mr Nanda Gopala Krishna for XPS.