TiN Coatings on Titanium Substrates Using Plasma Assisted Ion Implantation

Abstract

We present results on producing TiN coatings on titanium substrates, using Plasma-Based Ion Implantation and Deposition (PBII&D). In PBII&D the substrate is immersed into stationary plasma which contains the ion species to be implanted. A negative high voltage pulse is applied to the substrate, which causes the ions in the ion sheath surrounding the substrate to be accelerated across the sheath and implanted into the substrate. We have used a 13.6 MHz, 70 W, radio frequency (RF) plasma, produced with a mixture of 80% N2 + 20% H2, at 200 mTorr, with 4 kV, ≈ 10 μs pulses, at a 0.2 kHz rate. During the implantation process the titanium substrate is heated at 400°C range. The resulting TiN coatings are characterized using atomic force microscopy (AFM), x-ray diffraction (XRD), and Vickers hardness test. Optical emission spectroscopy (OES) is used to identify characteristic RF plasma species.