Experimental results of the synthesis of diamond-like high-pressure compounds using the high-pressure technique and the method of laser deposition are presented. Their combination of unique characteristics can be achieved by varying the B / C ratio. The possibility of spraying micron or nanosized carbon films with a high boron content opens the way to the use of such materials on an industrial scale. Hetero-diamonds with a high boron content have high elastic moduli, and diamond polycrystals doped with boron have metallic conductivity.
During solid-phase synthesis of piezoceramic materials based on complex oxides with a perovskite structure, anomalous thermal expansion of the pressed mixture of the initial reaction components is observed. Under certain conditions, the magnitude of this expansion can be an indicator of the degree of progress of solid-phase reactions. The analysis of the thermal expansion of a compressed mixture of powders of potassium, sodium and niobium carbonates during the synthesis of complex oxide of potassium and sodium niobate KNN is carried out. It is shown that on the basis of this analysis it is possible to estimate the temperature and completeness of the synthesis reaction. Several schemes for the solid-phase synthesis of this material are considered. From the material obtained, samples of piezoceramics with a density of up to 92 & # 37; from theoretical and value of piezomodulus d 33 to 1.010 -10 C / N
An original technique has been developed for controlling the strength characteristics of porous ceramic compositions of the abrasive grain - bond - pore system in order to obtain a composite that ensures maximum performance of the grinding tool made from it. The experimental and mathematical dependences of these characteristics, which form the basis of the methodology proposed by the authors, are given. An example of its implementation in the manufacture and operation of the tool is given.
Ceramic block supports were obtained by extrusion molding, varying the particle size and the conditions for obtaining corundum. The structural and mechanical properties of the molding mixtures were investigated, the textural and strength characteristics of the blocks after annealing were determined. It is shown that the use of corundum powder obtained by mixing particles of different sizes leads to the production of a molding mass of the 1st or 4th structural-mechanical type and makes it possible to prepare a ceramic block carrier with a channel density of about 200 pieces / inch 2 , mechanical strength of at least 4.3 MPa and high resistance to thermal cycles
The features of the action of cationic promoters on the thermochemical behavior of zirconium hydroxide have been investigated. It is shown that the composition and properties of the obtained materials are determined by the type, concentration of the promoter, and the temperature of formation of the oxide phase.
The results of a study of the passage of an electron beam with an energy of 10 keV through dielectric channels made of ceramics (zirconium dioxide) and pyroelectric crystals (lithium niobate) are presented. The dependences of the angle of deflection of the electron beam by the channels are measured at different angles of interaction of the beam with the inner walls of the channels. The results obtained indicate possible prospects for the use of dielectric surfaces as effective deflectors of accelerated charged particles.
Prospects for the use of optically transparent ceramics made of aluminum-magnesium spinel are considered. The technologies for the synthesis of spinel powders for subsequent use in the production of transparent ceramics are described.
The paper presents the results of a study on the resistance of VOK-60 cutting ceramics when processing hardened steel workpieces made of 45 steel of different hardness 45 HRC and 54 HRC. Tool life of a cutting ceramic insert when machining a harder workpiece by 41 & # 37; higher than when machining a less hard workpiece. A microstructural analysis of the damageability of the working surface was carried out and a mechanism for wear of the cutting plate was established. The reasons for the faster wear of the plate when processing a workpiece with a lower hardness are determined.
Oleksenko L.P., Maksimovich N.P., Matushko I.P., Chubaevskaya N.V. Nanoscale sensor materials based on CeO2 / SnO2? Sb2O5 // Russian Journal of Physical Chemistry. 2015.Vol. 89.? 3.S. 470? 475.
2. Mihaiu S., Braileanu A., Ban M. et al. Sn? Ce? O advanced mate-rials obtained by thermal decomposition of some precursors // Journal of Optoelectronics and Advanced Materials. 2006. V. 8. N 2. P. 572? 575.
3. Boronin AI, Korenev SV, Novopashin SA Catalysts for low-temperature CO oxidation based on Pd / CeO2 - SnO2 composites synthesized under nonequilibrium conditions // Proceedings of the II Russian Congress on catalysis? Roskataliz ?, Samara, 2? October 5, 2014 Samara, 2014. P. 104.
4. Scurtu M., Mihaiu C., Zaharescu M. Surface evolution of the Sn? Ce? O powders in various atmospheres // Reaction Kinetics, Mechanisms and Catalysis. 2012. V. 105. N 1. P. 135? 144.
5. Teterycz H., Klimkiewicz R., Laniecki M. Study on physico-chemaical properties of tin dioxide based gas sensitive materials used in condensation reactios of n-butanol // Applied Catalysis A: General. 2004. V. 274. P. 49? 60.
6. Khalipova OS, Kuznetsova SA, Galanov SI Synthesis of supported catalysts for deep oxidation of methane based on SnO2? CeO2 // Inorganic materials. 2016.Vol
. 52.? 4.S. 417? 422.
7. Wu S., Li C., Wei W. et al. Synthesis and photocatalytic property of Ce-doped SnO2 // Journal of rare earths. 2010. V. 28. P. 16? 18.
8. Gupta A., Kumar A., ??Hegde MS, Waghmare UV Structure of Ce1-xSnxO2 and its relation to oxygen storage property from first-principles analysis // The Journal of Chemical Physics. 2010. V. 132. Is. 19. P. 194702.
9. Ivanova AI Physicochemical and catalytic properties of systems based on CeO2 // Kinetics and Catalysis. 2009.Vol
. 50.? 6.S. 831? 849.
10. Ivanov VK, Shcherbakov AB, Baranchikov AE, Kozik VV Nano-crystalline cerium dioxide: properties, production, application. Tomsk: Publishing house Tomsk. University, 2013.12 p.
11. Spivakovsky VB Analytical chemistry of tin. Moscow: Nauka, 1975.252 p.
The possibility of increasing the strength characteristics of ceramics by introducing a ceramic-forming polymer polydimethylsilane into the charge is considered. When polydimethylsilane is introduced into the composition in the presence of a catalyst of molybdenum chloride, the transition of polydimethylsilane to polycarbosilane is observed, followed by the transition of the latter to silicon carbide. It is shown that the introduction of this additive at a mass content of more than 4% leads to an increase in strength characteristics, a decrease in open porosity.
