ELECTRODEPOSITION OF METALS AND ALLOYS FROM AQUEOUS SOLUTIONS. REVIEW OF WORK OF EMPLOYEES FROM V.I. VERNADSKY NASU

The article examines in a historical perspective the issues that have been associated with the theory and practice of electrochemical deposition over the years of existence of the V.I. Vernadsky Institute of General and Inorganic Chemistry of NAS of Ukraine. Research in the field of electrochemistry of aqueous solutions, which was and is being carried out at the Institute, made a significant contribution to theoretical and applied electro­chemistry: the theory of electrode pro­cesses, electrochemistry of complex compounds, masstransfer, chemical power sources, electrocatalysis, electrochemical devices, theoretical and engineering electroplating, hydroelectro­metallurgy, electrochemical ecology and a number of other areas of modern chemistry. This article highlights issues related to research in the field of electrodeposition, namely: theo­retical research in the field of electrodeposition, electrodeposition of metals and alloys, hydroelectrometallurgy, corrosion and anticorrosion coatings. It is proved the effect of complexation leads to the formation of elect­rochemically active and inactive coordination ions, a mechanism for the discharge of ions during the formation of a film on the electrode surface is also proposed. The regularities leading to the formation of powders and black deposits of metals are analyzed. The conditions for a stable electrolysis regime were identified, the concept of the electrochemical resistance of the system was introduced, and the relationship between the kinetic parameters of elect­rolysis and the structure of the coatings was shown. The works in the field of hydroelectrometallurgy, corrosion-resistant and protective coatings are analyzed. It is noted that the scien­tific achievements of the Institute’s scientists are widely known around the world.

Comparing Nuclear and Chemical Power Sources for MEMS/NEMS Applications

Nuclear batteries are a class of power sources that harvest energy from decaying radioactive isotopes to generate electricity for powering sensors and electronics. They are well known in the fields of space exploration and implantable medical devices, but are not widely known to micro or nano-technologists in general. Nuclear batteries are compared against chemical sources of energy applicable to small-scale systems, including energy harvesting prototypes and a mm-scale commercial lithium battery, utilizing the metrics of volumetric power and energy density. Nuclear batteries benefit from orders of magnitude more energy density than power sources derived from chemical reactions, however they also have orders smaller power density. For some sensor applications, nuclear batteries enable capabilities not possible with chemical energy sources, and examples are discussed.

Development of Coated Electrodes with Solid Wire and Flux-Cored Alloyed Wire for Microalloyed Steel Welding

In this paper, we will present our investigation of the quality of J55 microalloyed steel welds that were formed by a basic flux-cored wire electrodes that were of appropriate quality and alloyed with Ni and Mo. Based on the comparison and analysis of the obtained results related to the testing of the chemical composition, mechanical properties, toughness at test temperatures, and the microstructure of welding joints formed by a classic and specially coated rutile flux-cored electrode, we assessed the justification to switch from solid wire electrodes to flux-cored alloyed wire electrodes of appropriate quality. The research aim for the application of flux-cored wire electrodes instead of solid wire electrodes is based on the advantages pertaining to a flux-cored wire: molten metal from electrode wire is transferred in the form of fine droplets, easy welding and maximum productivity within all spatial positions related to welding, improved properties of welding joints, and increased productivity when compared to a classic solid wire. Our research encompasses the development of the experimental production at the Research and Development Center IHIS Belgrade (Development Institute for Chemical Power Sources), Serbia, of the new type of a coated electrode with improved welding properties when compared to a classic electrode intended for microalloyed steel welding.