Abstract
Ion-plated TiN films for watch case exteriors were studied in terms of decorative properties (appearance, coverage and color) and film structure. Using a substrate of 18-8 stainless steel, the application of over sputter cleaning by Ar discharge produced an austenite grain boundary on the substrate surface, to the detriment of decorative properties. Ion-plated TiN film had excellent film thickness distribution and coverage, and application of this technique to watch case exteriors was found to be ideal. Spectrophotometry showed that the shape of the reflectance curve of ion-plated TiN, TiNXCY film was similar to that of gold plating but the values were lower. The dependance of film structure on acceleration voltage was investigated by X-ray diffraction. A change in the orientation of the TiN (111) plane with acceleration voltage was observed by means of rocking curve, and the orientation was found to be affected by acceleration voltage. Stress in the TiN films was measured by X-ray techniques, showing that ion-plated TiN film had very high stress.
