Corrosion resistance of PAPVD TiN coating on AISI 304 stainless steel

In this work the corrosion resistance of PAPVD TiN hard coatings on AlSl 304 stainless steel with a titanium interlayer has been addressed Cyclic voltammetry corrosion tests in NaCl 3.5% solutions were performed for samples prepared by depositing TiN/Ti onto steel using different deposition parameters. The surface morphology of the samples was examined by using a scanning electron microscope (SEM) and phase analysis was performed by X-ray diffraction (XRD). The cyclic voltammetry curves showed two distinct behaviours. Firstly, a reduction in corrosion resistance it,as observed when current density was increased for the whole potential range studied The second observation, no less important, was the increase in corrosion resistance compared to the uncoated steel. The TiN films deposited showing (111) preferred orientation showed better corrosion resistance than films presenting other orientations.