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

• Published in: Transactions of the Institute of Metal Finishing 2018-05, Vol.96 (3), p.145-154
• Main Authors: Assala, O., Fellah, M., Mechachti, S., Touhami, M. Z., Khettache, A., Bouzabata, B., Weiβ, H., Jiang, X.
• Format: Article
• Language: English
• Subjects: 41Cr-Al-Mo7 nitride steel; Diamond-Like Carbon; friction; hardness; morphology; MW ECR-PACVD process; structure; wear
• ISSN: 0020-2967; 1745-9192
• DOI: 10.1080/00202967.2018.1453444

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) 3 C, Cr 3 C 2 and Cr 23 C 6 interlayer phases. DLC films showed a better wear resistance, higher hardness and low friction coefficient compared to nitrided layers tested for comparison.