Abstract

GIL, Linda et al. EFFECT OF TiN AND ZrN COATING DEPOSITION ON THE CORROSION RESISTANCE OF AA7075-T6 ALUMINIUM ALLO. uct [online]. 2010, vol.14, n.56, pp.157-164. ISSN 1316-4821.

The present investigation has been carried out in order to study the effect of the deposition of both a TiN and a ZrN coating by means of physical vapor deposition (PVD), on the corrosion resistance of an AA7075-T6 aluminum alloy. The corrosion resistance was evaluated by means of potentiodynamic polarization measurements. The morphological characterization of the coatings before and after the corrosion tests was conducted by means of scanning electron microscopy (SEM) techniques coupled with energy dispersive X-ray analysis (EDS), as well as X-ray diffraction (XRD). The potentiodynamic polarization measurements showed that the deposition of the ZrN coatings gave rise to a significant shift of the corrosion potential (E_corr) towards a more positive potential and a decrease of the corrosion current density (i_corr), in relation with the behavior displayed by the uncoated substrate. On the contrary, the deposition of the TiN coating did not improve the corrosion behavior of the substrate.

Keywords : TiN; ZrN; PVD; Coatings; Corrosion.