Structural, mechanical and tribological properties of ZrC thin films deposited by magnetron sputtering

• Published in: Vacuum Vol. 169; p. 108909
• Main Authors: Gilewicz, Adam, Mydłowska, Katarzyna, Ratajski, Jerzy, Szparaga, Łukasz, Bartosik, Przemysław, Kochmański, Paweł, Jędrzejewski, Roman
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-11-2019
• Subjects: Friction; Magnetron sputtering; Mechanical properties; Phase composition; Wear; Zirconium carbide; Mechanical properties; Magnetron sputtering; Zirconium carbide; Phase composition; Friction; Wear
• ISSN: 0042-207X; 1879-2715
• DOI: 10.1016/j.vacuum.2019.108909

In the present study, thin coatings of ZrC were deposited by reactive pulsed magnetron sputtering of a zirconium target in an Ar + C2H2 atmosphere on HS6-5-2 steel substrates, and their phase composition, microstructure, coating chemistry, mechanical and tribological properties were studied. The phase composition and microstructure were studied using standard techniques such as X-ray diffraction (XRD) and scanning electron microscopy (SEM). The surface chemistry of the coatings was analysed by using a surface sensitive X-ray photoelectron spectroscopy (XPS). The experimental results were also compared with the results of the ZrC coatings produced using a reactive atmosphere of Ar + CH4 obtained by other authors. In particular, a correlation between the phase composition, microstructure, mechanical and tribological properties of the ZrC coatings is developed and discussed here. Carbon appears in these coatings as an amorphous structure with a high fraction of sp2 bonds and the share of this phase in the coating grows with an increase of the total carbon concentration. Results reveal rather narrow range of carbon concentrations near 50 at. %, in which the coatings are characterized by the maximum values of hardness and Young's modulus.
•Appearance of an amorphous carbon phase with a high share of sp2 C–C bonds.•Evolution of structure from Zr to nc-ZrC in a-C:H matrix with increase carbon concentration.•Maximum hardness and Young's modulus at approximately 50% of carbon atoms in the ZrC coating.•Increase in carbon concentration results in a lower COF value and a lower wear rate.