Titanium diboride (TiB2) coatings were prepared by electroplating in fluoride-chloride electrolytes (KF-KCl)containing K2TiF6 and KBF4 as the electrochemically-active components. An attempt was made to correlate the thermody-namic prediction and experimental observations. Thick, adherent, and uniform TiB2 coatings were obtained and the coatingmicrohardness reaches the value of 33 GPa. The effects of the current density on the mechanical properties, structures, andmorphologies of the coatings were studied. XRD analysis indicates that the preferred orientation of the coatings is (001),which is in accordance with the prediction of the two-dimensional crystal nuclei theory. Thermodynamic prediction and ex-perimental results show that some phases such as TixCy and BaCb are absent at the interface, which indicates the substrateand coatings bind mechanically or physically. Some cracks exist at the interface, which is attributed to the difference be-tween the coefficients of thermal expansion of TiB2 and graphite. Titanium diboride (TiB2) coatings were prepared by electroplating in fluoride-chloride electrolytes (KF-KCl) containing K2TiF6 and KBF4 as the electrochemically-active components. An attempt was made to correlate the thermody- namic prediction and experimental observations. Thick, adherent, and uniform TiB2 coatings were obtained and the coating microhardness reaches the value of 33 GPa. The effects of the current density on the mechanical properties, structures, and morphologies of the coatings were studied. XRD analysis indicates that the preferred orientation of the coatings is (001) , which is in accordance with the prediction of the two-dimensional crystal nuclei theory. Thermodynamic prediction and ex-perimental results show that some phases such as TixCy and BaCb are absent at the interface, which indicates the substrate and coatings bind mechanically or physically. Some cracks exist at the interface, which is attributed to the difference be-tween the coefficients of thermal expansion of TiB2 and graphite.