Electrochemical Synthesis of Tib2 Layers out of Flinak Electrolyte in the Presence of Tacl5 Additive

TiB2 coatings on Mo substrates were electrodeposited out of a FLiNaK electrolyte in the presence of TaCl5 additive. The results show that a low concentration of TaCl5 in the melt changes significantly the chemical composition and consequently, the properties of the coatings. The energy-dispersive X-ray analysis indicates up to 10 atom % Ta in the TiB2 coatings. X-ray phase analysis demonstrates the changes in the texture of TiB2 in the < 001 > direction. Codeposition of TaB2 in a TiB2 layer decreases the grain size and improves the smoothness of the layer. Addition of TaCl5 in the electrolyte permits to obtain TiB2-TaB2 layers of high quality and makes the process reproducible. In addition, the individual electrochemical behavior of the starting compounds, K2TiF6, KBF4, and TaCl5, as well as their mixtures was investigated in the FLiNaK electrolyte by means of cyclic voltammetry. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3489403] All rights reserved.