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, 46.5:11.5:42molar ratio) with solutes K2TiF6 andKBF4 with the electrochemically-active components in themolar ratio of one to five. The coatings produced by PIC show improvements in morphology and microstructure for the suitable conditions: i=0.5 A/cm, frequency=100 Hz, the time ratio tc/ toff (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. © 2006 Elsevier B.V. All rights reserved.