1994 年 45 巻 4 号 p. 422-427
Titanium films were electrodeposited on 304 stainless steel by constant current and pulse current methods from the eutectic mixture of KCl-NaCl-LiCl containing 2mol% K2TiF6, with and without the additive CeF3. The influence of electrodeposition conditions on the crystal orientation and morphology of the films was investigated by X-ray diffraction and scanning electron microscopy, respectively. In the case of melts without CeF3, increasing temperature caused the Ti films electrodeposited by a constant current to exbibit (002) preferred orientation, while those deposited by pulse current exhibited (110) preferred orientation. In the case of melts with 1mol% CeF3, increasing temperature caused the preferred orientation of the Ti films to change to (110) independent of current waveform. The morphology of the Ti films showed well-crystallized grains, which became large with increasing temperature. Under identical conditions, grains of the films from the melts with CeF3 were larger than those from those without.
Corrosion resistances were estimated by anodic polarization in 3% NaCl solution at 298K. It was found that the films deposited by pulse current or from melts with 1mol% CeF3 had better corrosion resistance than those obiained at constant current or from melts without CeF3.