Mechanical and corrosion study of diamond-like carbon coating on NiTi alloys

Diamond-like carbon (DLC) coatings were prepared on NiTi alloys using plasma immersion ion implantation and deposition. The evaluation of surface hardness using nano-indenter reveals that the DLC coated NiTi alloys is much harder than that of the uncoated sample. The scratch test reveals that the DLC coating has good adhesion strength between the coating and substrate. Anodic polarization has been carried out to examine the electrochemical corrosion behavior of the coated and uncoated samples. The result indicates that the corrosion resistance of the NiTi alloys is improved by the coating.