Thin Solid Films, Vol.278, No.1-2, 67-73, 1996
Preparation of Tin Film on Brass by CAPD as a Decoration System
Titanium nitride (TiN) films are deposited onto brass (62 wt.% Cu and 38 wt.% Zn) substrates by the cathodic are plasma deposition process (CAPD). The colour main wavelength and reflectivity of the films are measured by a chromatometer. The pore ratios of the films with different thickness are investigated by a light transmission image analysis system. The corrosion resistance of this system is studied by electrochemical analysis. Scanning electron microscopy, transmission electron microscopy and Auger electron spectroscopy are employed to study the metallography, the preliminary deposition process of CAPD and the interface between the films and substrates respectively. The results show that : (1) the decorative property of TiN/brass system prepared in a certain CAPD parameter range can reach that of standard 24 carat gold; (2) as the nitrogen partial pressure increases, the main wavelength of the film increases and tends to values near and around that of 24 carat gold and the reflectivity of the film increases and reaches that of 24 carat gold; (3) as the substrate temperature increases from about 190 degrees C to about 700 degrees C, the reflectivity of the film dropped seriously but the main wavelength of the film is hardly affected; (3) the light transmission pore ratio falls as a reciprocal function of thickness of the TiN film; (4) finally, the corrosion resistance of this system in an artificial human sweat solution is improved largely compared with that of the bare decorative brass.