ENHANCED INDUSTRIAL APPLICDABILITY OF ALUMINUM ALLOY BY COATING TECHNIQUE WITH TITANIUM/CARBON COMPOSITIONALLY GRADIENT FILM USING MAGNETRON CO-SPUTTERING

摘要

Coating of Aluminium alloy substrates with Ti/C compositionally gradient films was examined by magnetron sputtering, in order to improve not only the abrasion resistance of the alloy but also the adhesion between the deposited film and the alloy substrate with preserving the high hardness of such ceramic coatings. The Ti/C compositionally gradient films were deposited by co-sputtering of 2 sputter cathodes which had a pure titanium target and a titanium carbide target respectively, and their compositionally gradient was realized by varying continuously the electric power supplied to each sputter cathode. Under visual observation, the obtained Ti/C compositionally gradient films appeared to be uniform and adhesive. According to AES in-depth profiles, the carbon(C) concentration in the film gradually decreased in depth direction from trhe surface toward the substrate, confirming that a Ti/C compositionally gradient film had formed on the alloy substrate. On the basis of XRD, it was found that titanium carbide and a -titanium phases were formed in the gradient film. Furthermore the Vickers hardness of the film reached over Hv=2600. Therefore the abrasion resistance of the alloy and the adhesion of the hard coatings were expected to be improved by this method.