In vitro evaluation of diamond-like carbon coatings with a Si/SiC_x interlayer on surgical NiTi alloy

摘要

Diamond-like carbon (DLC) coatings were produced with a Si/SiC_x interlayer by a hybrid plasma immersion ion implantation and deposition process to improve the adhesion between the carbon layer and surgical NiTi alloy substrate. The structure, mechanical properties, corrosion resistance and biocompatibility of the coatings were evaluated in vitro by Raman spectroscopy, pin-on-disk tests, potentiodynamic polarization tests and simulated fluid immersion tests. The DLC coatings with a Si/SiC_x interlayer of a suitable thickness have better adhesion, lower friction coefficients and enhanced corrosion resistance. In the simulated body fluid tests, the coatings exhibit effective corrosion protection and good biocompatibility as indicated by PC12 cell cultures. DLC films fabricated on a Si/SiC_x interlayer have high potential as protective coatings for biomedical NiTi materials.