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A review of experimental investigations of electrochemical deposition of tungsten from ionic melts is presented. The electrolytes used are systematized depending on the structure of deposits.

We systematize the well-known electrolytes for the high-temperature electrochemical synthesis of borides, carbides, and silicides of metals of the IV–VIA groups by the classes of synthesized compounds. We also generalize the conditions of their deposition from electrolytes of different compositions and analyze the results of recent investigations in this field. Hypotheses on the possible mechanisms of synthesis processes are advanced. Furthermore, we prove the possibility of electrochemical synthesis of borides and silicides of metals of the IV group and carbides of metals of the VI group in the thermodynamic mode as well as that of carbides of metals of the V group and borides and silicides of metals of the VI group in the kinetic mode. We demonstrate the possibility of using carbon dioxide or carbonates of alkali metals as a source of carbon in the synthesis of metal carbides. It is established that the composition of synthesized powders is determined by the concentrations of components in the electrolyte, temperature, cathodic current density, and the duration of electrolysis. We show the possibility of synthesis of three-component hard-alloy carbide compositions. Finally, we determine the technological parameters of production of single-phase powders.

Brief historical review of the high-temperature electrochemical syntheses (HES) of protective coatings from ionic melts is given. The modern state of the branch and the problems met by the HES in producing high-melting compounds of IV–VIA group metals from ionic melts are considered.

The present state of research in the field of high-temperature electrochemical synthesis of the carbides, borides, and silicides of Group IV-VI metals in ionic melts is reviewed. Modern problems in electrochemical synthesis and possible future developments are discussed. The results of recent studies of high-temperature electrochemical synthesis are reported. The bibliography includes 103 references.

Information on the chemistry and electrochemistry of molybdenum in ionic melts is considered and generalized. Data on the electrode potentials, chemical reactions involving molybdenum compounds, and mechanisms of electroreduction of the metal and its electrodeposition in the form of various cathodic deposits are discussed and systematized.

Data on the electrochemistry of molybdenum in melts are considered and generalized. Data on the mechanisms of metal electroreduction and electrodeposition in the form of different cathodic deposits are discussed and systematized. The state of the art in these areas is analyzed, and the prospects are discussed.

The electrochemical behavior of zirconium and boron and the synthesis of disperse zirconium diboride powders and coatings from the chloride-fluoride melts have been studied by voltammetry, galvanic and potentiostatic electrolysis, and X-ray phase analysis. It has been shown that the electrochemical reduction of Zr in the chloride-fluoride melts has the different mechanisms for the low and high concentration of the fluoride ion in the melt. In the first case, it proceeds according to the scheme of auto-inhibition; in the second case, the 4-electron reverse one-stage discharge process is observed. By adjusting the ratio [F-]: [Zr(IV ) ] in the melt, it is possible to find the conditions for the implementation of the one-stage 4-electron discharge process of zirconium and its diboride. During the electrometallurgical synthesis of ZrB2, the electro-active particles that formed as a result of the chemical interaction of zirconium- and boron-containing particles and that have different compositions than those formed in the partial zirconium- and boron-containing melts are discharged.

Information on electroreduction mechanisms of electroplating VI-A group metal coatings from ionic melts is considered and summarized. The state of the art in this field of studies is analyzed and their prospects are discussed.

Information on the chemistry and electrochemistry of chromium in ionic melts is analyzed. Data on chemical reactions with chromium compounds, the electroreduction of chromium, and its electrodeposition (in the form of cathodic deposits) are discussed.