Nanostructured vacuum arc deposited titanium coatings

Titanium coatings are mainly attractive due to their biocompatibility, which makes them reliable for the design of medical instruments or implants in the human body. Ti coatings on silicate glass substrates have been produced using a nonfiltered vacuum arc deposition technique. The dependence of the deposition rate on the distance from the cathode both in lateral and transversal directions was investigated. The average roughness, R sub a , decreases with the distance, showing a transition area between the microparticle-containing and microparticle-free Ti films. R sub a depends strongly on the number of microparticles. A linear dependence of R sub a on the discharge current was obtained only for substrates far enough from the cathode. For substrates close to the cathode the dependence is governed by the microparticle density. Transmission electron microscopy (TEM) reveals dense structure with nanograins.