Preparation of the TiB2 coatings by electroplating in molten salts

The improvement of titanium diboride (TiB₂) coatings over the molybdenum substrate was investigated by comparing the electrochemical techniques of continuous current plating (CCP) and periodically interrupted current (PIC). The solvent used was a eutectic Flinak mixture (LiF-NaF-KF, 46.5:11.5:42 molar ratio) with solutes K₂TiF₆ and KBF₄ with the electrochemically-active components in the molar ratio of one to five. The coatings produced by PIC show improvements in morphology and microstructure for the suitable conditions: i = 0.5 A/cm², frequency = 100 Hz, the time ratio t_c/t_off (current on/current off) = 4/1. X-ray diffraction (XRD) analyses indicated that the coatings are composed of the relatively pure TiB₂ and the preferred orientation is [001] + [110], which is in accordance with the prediction of the two-dimensional crystal nuclei theory.