Papers by Author: N.T. Kuznetsov

Abstract: The main results of the investigation of boron-containing compounds that are planed to use as light components for creation of metal-matrix composites (MMC) are presented in the paper. A number of new general procedures have been developed, physical-chemical properties of boron cluster anions BnHn 2- (n = 10, 12) were investigated. Method of MMC fabrication is based on mechanical alloying and following compaction.

Abstract: In recent years, industries have increasingly demanded novel materials of low density (and, therefore, weight) and high strength. Such materials are required for all kinds of transport, especially for automobile and aviation industries. Lower weight vehicles would allow for reduced fuel consumption, which increases the transportation efficiency (the economical point of view) and a corresponding decrease of emission of pollutants to the atmosphere (the ecological point of view). This is why the development of materials with decreased densities is of great importance. The aim of this study was to develop novel materials as reinforcing elements for metal matrix composites. Boron crystalline compounds are proposed to be used, including the derivatives of higher boron– hydrogen anions BnXn 2- n = 10,12, X = H (in some cases – halogen, for example, Cl) as their respective densities meet the criteria. The study pursued two goals: (i) to develop a method for producing these boron hydrides and (ii) to investigate the structure and properties of these boron hydrides.

Abstract: The major objective of our studies was the thermodynamic analysis of the nSiС+SiO2 system and revealing potentialities for the implementation of the SiC gas-phase transport conditions. As a result of thermodynamic scanning of the chemical activity of nSiС+SiO2 system the conditions for implementing the SiC gas-phase transport were found out within a wide temperature range. It was found out that the basic process in the gas-phase transport of silicon carbide is: SiCs + SiOg→ 2Sig + СОg SiC evaporation at T2 2Sig + СОg → SiCnanowhiskers + SiOg SiC deposition at T1 Sequential evaporation and deposition of silicon carbide result in the growth of SiC crystals from a gas phase. The processes of SiC gas-phase transport and deposition were experimentally realized. Synthesized were SiC nanocrystals over 300 μm long, ~ 300 nm in diameter that forms a three-dimensional subskeleton inside the carbon skeleton.