Low Wear and Low Friction DLC Coating With Good Adhesion to CoCrMo Metal Substrates. Issue 12 (2nd November 2018)

• Record Type: Journal Article
• Authors: Cano, David; Lousa, Arturo; Esteve, Joan; Ferrer‐Anglada, Núria
• Is Part Of: Physica status solidi. Volume 255:Issue 12(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-11-02
• Subjects: coatings -- diamond‐like carbon -- friction -- prostheses -- wear; Solid state physics -- Periodicals; Solids -- Periodicals; Atomic structure -- Periodicals; 530.41
• DOI: 10.1002/pssb.201800225
• Languages: English
• ISSNs: 0370-1972

Abstract

Abstract : A challenge currently facing the orthopedics sector consists in the durability problems posed by joint prosthesis based on metal‐on‐metal contacts. While the diamond‐like carbon (DLC)‐based coating solves the shortcomings of wear and friction found in the uncoated metal parts, they are generally subject to adhesion failures that may prove to be catastrophic. Our coatings were deposited with a specific multilayered composition that changes from highly metallic at the metal interface, up to a DLC at the sliding contact region. These coatings show very good wear performance results when tested in a highly humid air atmosphere as well as when they are tested in water immersion or in bovine serum. The friction coefficients of our DLC‐against‐DLC tribological pair are found to be always less than 0.1, while wear rates are extremely low, under 2.5 × 10 −8 mm 3 /N m, and it produces highly polished surfaces. The compressive stresses of our coatings are always lower than 2.5 GPa, and when combined with good interface adhesion to the CoCrMo metal substrates, make the coatings highly resistant to delamination even after prolonged test runs. Raman analyses do not reveal any detectable changes even after very long test runs, indicating that no tribochemical reactions occur on the DLC coating. Abstract : The authors present the development and analysis of a multi‐layer coating based on DLC (diamond‐like carbon) material with intermediate layers of Cr, CrN, and CrC on metal substrates. Friction, wear, adhesion, and abrasion resistance as tribological properties of less‐hydrogenated, multilayered DLC coatings have been investigated. Scratch‐test plus Raman spectroscopy are used to analyze the adhesion. Good adhesion to the CoCrMo metal substrates, good wet wear performance, and long service life are promising in the use of this DLC as an effective coating for metal‐on‐metal prostheses.