CORROSION BEHAVIOR OF TI TIN MULTILAYER COATED TOOL STEEL/

The corrosion behaviour of Ti/TiN multilayer coated tool steel has bee n investigated by potentiodynamic measurements in 0.1 M H2SO4 and comp ared with single layer coatings of Ti and TiN, respectively. All the c oatings had a total thickness of about 1 mu m. Two multilayer coatings of different sublayer thicknesses were investigated i.e. 0.5 and 0.08 mu m. An improved protection of the substrate was observed by using m ultilayer coatings with thick sublayers. To obtain good protection of the substrate, the columnar structure of ion plated TiN should be avoi ded. This is achieved by introducing Ti sublayers with a higher degree of perfection which hinder columnar film growth. The introduction of a few thick sublayers was more efficient and resulted in better corros ion protection than many thin sublayers. (C) 1998 Elsevier Science S.A .