Low-temperature metal ion implantation assisted deposition of hard coatings

Wear-resistant coatings were deposited by using a vacuum arc ion plating technique combined with pulsed plasma surface treatment. By combining the pulsed processes of the bias voltage as well as of a metal plasma ion implantation (MPII), the substrate temperature was kept below 160 degreesC. The metal vapor vacuum arc (MeVVA) ion source used was equipped with a Cr cathode, a low-frequency ignition system and high voltage supplies for the ion acceleration and plasma shielding, respectively. Mechanical properties of the coatings like thickness, hardness and adhesion were clearly influenced by the metal ion bombardment before and during the deposition process. This will be shown for TiN-coated cemented carbide tools modified by Cr ion implantation with an ion acceleration voltage varied up to 40 kV. The findings of nanoindentation measurements are consistent with the results of X-ray stress analysis (XSA) investigations. The effect of the metal ion implantation process into the surface region of the carbide tools and the growing coatings on the tool lifetime will be discussed. (C) 2004 Elsevier B.V. All rights reserved.