Enhanced corrosion resistance of TiN prepared by plasma-based ion implantation

The injection of nitrogen ions into pure titanium has been performed by the plasma-based ion implantation with a negative voltage of 10 kV, pulse widt h of 10 mu s and a repetition rate of 100 Hz. The ESCA/AES analysis indicat es the nitrogen deposition with a peak at 27 nm from the surface and the fo rmation of TiN. The dissolution current density of the implanted samples wa s decreased about two orders of magnitude less than that of the unimplanted sample, indicating a remarkable enhancement of the corrosion resistance of the ion-implanted titanium. The increase in corrosion resistance appears a t the ion doping concentration exceeding approximately one-fiftieth of the atomic density of titanium. However, for doping concentration above the ato mic density of titanium, the improvement of corrosion resistance was slight ly reduced. (C) 2000 Elsevier Science Ltd. All rights reserved.