Effects of carbon doping on microstructure, electrochemical and tribo-corrosion performances of biocompatible TiZrNbTaMoCxNy coatings

Abstract

To improve the longevity of medical devices in physiological environments, a series of TiZrNbTaMoCxNy coatings were fabricated on 316L stainless steel using RF magnetron sputtering. The work demonstrated that appropriate carbon doping can effectively enhance the density, electrochemical properties, and resistance to tribo-corrosion of the coatings. Among the tested samples, coating S4 with a carbon content of 24 at. % exhibited the lowest wear rate (6.496 × 10−7 mm3 N−1 m−1) during the tribo-corrosion tests, due to its favorable lubrication characteristic (COF = 0.127) and enhanced resistance to plastic deformation (H3/E2 = 0.78 Gpa). Additionally, coating S5 with a carbon content of 28 at. % showed superior electrochemical performance (icorr = 5.21 × 10−8 A), attributed to its higher coating density and ability to form passive films. Both S4 and S5 exhibited superior biocompatibility compared to 316L.