Preparation and characterisation of diamond-like carbon films prepared by MW ECR/PACVD process deposited on 41Cr–Al–Mo7 nitrided steel

ABSTRACT

In the present work, Diamond-Like Carbon (DLC) films were deposited by the Microwave Electron Cyclotron Resonance/Plasma-Assisted Chemical Vapour Deposition process on 41Cr–Al–Mo7 nitrided steel using a benzene–argon gas mixture. The quality of DLC films grown on nitrided steel using different deposit conditions such as benzene flow rate, temperature and time was investigated. Microstructural analysis by Raman spectroscopy showed main G-band peaks are localised between 1564 and 1595 cm⁻¹, while the D-band peaks are centred at 1297 cm⁻¹. Fourier Transform Infrared Spectroscopy showed the peaks attributed to C–H bending and stretching vibration modes are in the range of 2600–3100 cm⁻¹. The microstructure, surface morphology and mechanical properties of the films were examined by X-ray diffraction, atomic force microscopy and use of a Vickers indenter (Zwick). The deposition parameters of the coatings have been studied and optimised to improve mechanical properties. The observed increase in adhesion is related to the formation of (Fe,Cr)₃C, Cr₃C₂ and Cr₂₃C₆ interlayer phases. DLC films showed a better wear resistance, higher hardness and low friction coefficient compared to nitrided layers tested for comparison.

KEYWORDS:

• Diamond-Like Carbon
• structure
• morphology
• hardness
• friction
• wear
• 41Cr–Al–Mo7 nitride steel
• MW ECR-PACVD process

Acknowledgements

The authors would like to thank the Chair of Department of Surface and Materials Technology (LOT) at the University of Siegen, Germany for support.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

M. Fellah http://orcid.org/0000-0003-0615-6711

Additional information

Funding

This work has been supported by the Heinrich Hertz Stiftung (Project B 42 Nr. 27/97). Heinrich Hertz Foundation Promoting International Research Exchanges, Heinrich Hertz-Stiftung. Völklinger Straße 49 40221 Düsseldorf Germany, www.heinrich-hertz-stiftung.de, www.wissenschaft.nrw.de