INFINA (EX INFIP)   05545
INSTITUTO DE FISICA INTERDISCIPLINARIA Y APLICADA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Hardness and Wear Characterization of Titanium Thin Films Obtained with a Cathodic Arc Employing a Magnetic Concentrator.
Autor/es:
F. BERMEO; A. KLEIMAN; A. MÁRQUEZ
Lugar:
Mar del Plata
Reunión:
Workshop; 14th Latin American Workshop on Plasma Physics (LAWPP 2011).; 2011
Resumen:
Thin film growth with cathodic arc devices has been widely investigated due to this technique promotes the formation of dense nanostructured films with good adhesion and a very high deposition rate. In cathodic arc discharges a metallic plasma jet is ejected from the cathode surface. If a substrate is located facing the plasma jet its surface is coated with a metallic film. The main disadvantage of vacuum arc deposition is the emission of macroparticles (MPs) from the cathode. MPs in the coatings produce protuberances and depressions on the substrate surface that not only increase the roughness, but also degrade mechanical properties. Employing a magnetic field parallel to the propagation direction of the plasma jet, the ions are concentrated on this direction and the plasma density increase, then the deposition rate increase and the fraction of MPs decreases. In this work, Ti films were grown on stainless steel AISI 316 with a DC cathodic arc employing a magnetic concentrator. The magnetic duct was 10 cm in diameter and 20 cm length with a magnetic field of 120G in the region of maximum field value. The entrance of the magnetic duct was located at 10 cm from the cathode surface. The substrate temperature was maintained at (230 ± 10)ºC during the discharge by means of a heater integrated to the vacuum chamber. The samples were placed in front of the cathode at different distance respect to the entrance of the magnetic concentrator. The uniformity and morphology of the films as well as the presence of MPs were characterized for the different sample positions and correlated with the hardness and tribological properties of the films. The morphology was analyzed using a SEM microscopy and the composition was detected by EDS. The uniformity of the films was studied with a colotester and with a prefilometer, The hardness measure was made by a Nanovea nanoindentator and the wear test by a CSEM tribometer. The experimental results showed that films with the best mechanical properties (highest hardness, elastic modulus, and lowest friction coefficient and wear rate) corresponded to those grown at the position where the magnetic field was maxima.