Structure–property relations in Cr–C/a-C:H coatings deposited by reactive magnetron sputtering

• Published in: Surface & coatings technology Vol. 200; no. 1-4; pp. 1147 - 1150
• Main Authors: Gassner, G., Mayrhofer, P.H., Mitterer, C., Kiefer, J.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Lausanne Elsevier B.V 01.10.2005; Elsevier
• Subjects: Applied sciences; Cross-disciplinary physics: materials science; rheology; Cr–C/a-C:H; Exact sciences and technology; Low friction; Materials science; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Nanocomposite; Other topics in materials science; Physics; Production techniques; Surface treatment; Unbalanced magnetron sputtering; Cr–C/a-C:H; Nanocomposite; Low friction; Unbalanced magnetron sputtering; Plasma; Magnetron; Mechanical properties; Coatings; Carbon; Composite material; Sputtering; Surface treatment; Cr-C/a-C:H; Friction; Amorphous hydrogenated material; Physical vapor deposition; Reactive sputtering
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2005.02.186

Amorphous hydrogenated carbon (DLC or a-C:H) coatings have been the subject of intensive research activities within the last two decades due to their superior mechanical and tribological properties. Recently, a nanocomposite concept for severe tribological applications has been proposed, where metal carbides providing enhanced wear resistance are embedded in a lubricating a-C:H matrix. The aim of this work is to investigate coatings based on Cr–C/a-C:H with respect to their structural, mechanical and tribological properties. Coatings in a range of compositions were prepared by reactive unbalanced magnetron (UBM) sputtering from a metallic Cr target in an Ar–CH4 atmosphere. X-ray diffraction and Raman spectroscopy were used to characterize the phase composition of the chromium carbide and a-C:H phases. Dry sliding experiments against different ball counterparts were conducted to determine the friction coefficients. The friction coefficients as well as coating hardness were correlated to different sp3/sp2 a-C:H and chromium carbide fractions within the coatings. The lowest friction coefficients of ∼0.15 could be obtained for coatings deposited at high CH4 partial pressures.