Abstract
Thin film coatings toward various types of materials have been used for protecting substrate surface from corrosion damages or adding a lot of functions to them. Till now the studies have been mainly conducted concerning mechanical and chemical properties of TiN thin film coating. However, nanometric defects and cracks were always existed in coated thin film from the initial stage. In actual environment, degradation was generated by corrosive solution intruded from the nanometric defect. Therefore, localized corrosion process toward pitting corrosion or crevice corrosion of coated thin film must be understood in relatively mild environment such as aqueous environment with Cl^- ion when degradation of thin film was examined. For this purpose, morphological changes of localized corrosions were necessary to be grasped through conducting sub-micrometer order observations of generated defects in thin film. Therefore in this study, crevice corrosion resistance of coated specimen was improved through conducting previous treatment of N^+ ion bombardment before TiN coating. Then, localized corrosion process in coated TiN thin film in 3%NaCl aqueous solution was investigated in detail using Atomic Force Microscope (AFM).
