Electrochemical corrosion and materials properties of reactively sputtered TiN/TiAlN multilayer coatings

TiN/TiAlN multilayers of 2 μm thickness were successfully prepared by reactive DC magnetron sputtering method. XRD pattern showed the (1 1 1) preferential orientation for both TiN and TiAlN layers. XPS characterization showed the presence of different phases like TiN, TiO2, TiON, AlN and Al2O3. Cross sectional TEM indicated the columnar growth of the coatings. The average RMS roughness value of 4.8 nm was observed from AFM analysis. TiN/TiAlN coating showed lower friction coefficient and lower wear rate than single layer coatings. The results of electrochemical experiments indicated that a TiN/TiAlN multilayer coating has superior corrosion resistance in 3.5% NaCl solution.