bond and a decrease in strength, but to an increase in heat resistance.
UDC 621.315.592
N. V. Novikov, T. A. Nachalnaya, S. A. Ivakhnenko, O. A. Zanevsky, I. S. Belousov, V. G. Malogolovets, G. A. Podzyarei, L. A. Romanko (Kyiv)
Defectiveness and impurity composition of semiconductor diamonds grown under temperature gradient conditions
Large (≈ 6 mm) single crystals of semiconductor synthetic diamonds grown on a seed by the temperature gradient method were studied. Their impurity-defect composition and the distribution of the main electrically active impurities over the volume of the crystals were investigated using electron paramagnetic resonance, infrared spectroscopy and cathodoluminescence. The volt-ampere characteristics and the temperature dependence of electrical conductivity were measured. It was shown that the potential relief formed by the electric fields of the inhomogeneities of the distribution of acceptor and donor centers plays a decisive role in the processes of charge transfer. The results of the work indicate the prospects of using the temperature gradient method to obtain large single crystals of semiconductor diamonds (type IIb) with specified electrical parameters, and the possibility of significantly expanding the use of such crystals (or their fragments) in the electronics industry. UDC 544.72
V. M. Perevertaylo, O. B. Loginova (Kyiv)
Classification of additives in growth media by their effect on the diamond crystallization process
A comprehensive study of the patterns of change in capillary characteristics (wettability, adhesion, surface and interfacial tension) in crystal-melt systems depending on the composition of the growth medium and the structure of the corresponding phase diagrams allowed us to conclude that there is a correlation between the capillary properties of the melt (bulk and surface properties of the system), the degree of transformation, the number of crystallization centers, the size and morphology of the resulting diamond crystals, and to develop a classification of additives in growth media by their effect on the diamond crystallization process.
UDC 669: 621.762
O. V. Pshenichnaya, G. K. Kozina (Kyiv)
Formation of a bond during the production of heterophase ceramic material AlN—TiN
A mechanism for the formation of an adhesive bond between phases in the ceramic composite material AlN—TiN during sintering is proposed. Various methods of analysis have shown that industrial nitride powders are enriched with impurities, primarily oxygen. The presence of aluminum vacancies and impurity oxygen atoms in the aluminum sublattice in the AlN phase promotes the formation of a limited solid solution of aluminum substitution by titanium in the contact zone of AlN particles, which leads to the displacement of oxygen to the surface with the growth of the spinel phase layer Al11O15N. The mass transfer process during sintering of the AlN—TiN material is activated by the liquid phase formed by the eutectic reaction between aluminum oxide and spinel.
UDC 676.747
A. F. Ilyushchenko, M. T. Zabavskiy, L. P. Pilinevich, G. A. Sheko, T. K. Azarova (Minsk, Belarus)
Porous abrasive material based on synthetic diamond powder
The article presents the results of a study on the creation of a porous abrasive wheel based on synthetic diamond powder and a metal binder containing a pore-forming agent. The composition of the charge, pressing and sintering modes are presented, and the effect of the pore-forming agent on the pore size of the wheel structure is shown. The effect of the amount of lubricating-cooling liquid supplied through the pores on the temperature reduction in the grinding zone is studied.
UDC 621.922.02-49.2:697.8.052
V. V. Skryabin, V. I. Sidorko, Yu. D. Filatov (Kyiv)
Regularities of Surface Formation of Products from Aluminosilicate Materials
A method for calculating the intensity of tool wear in various areas of its working layer has been developed. The regularities of surface formation of products from aluminosilicate materials for different processing schemes have been studied and it has been shown that they make it possible to solve the problem of increasing the efficiency of the polishing process for these materials.
UDC 681.7.023.7
V. V. Rogov, N. D. Rublev, A. V. Troyan, V. N. Popelnyuk (Kyiv)
Development of technology for finishing precision processing of functional surfaces of optical and electronic parts made of synthetic monocorundum (sapphire)
The article presents the main technical requirements for the functional surfaces of parts made of monocorundum (sapphire) for optical and electronic equipment, and considers the level of modern technology for their finishing precision processing. The article presents the results of laboratory tests of a new method and tool for finishing, developed in the ISM NAS of Ukraine, which provide the necessary requirements for the processing of these parts.
UDC 621.762
T. M. Duda, Yu. I. Nikitin, V. G. Poltoratsky, L. D. Khripkova, V. S. Shamraeva, T. M. Nesterenko (Kyiv)
Some features of obtaining and physical and mechanical properties of diamond powders metallized with composite chemical coatings with the inclusion of UDD
Optimum conditions for metallization of diamond powders to composite chemical coatings with simultaneous co-precipitation of nickel or copper with particles of ultra-dispersed diamond powders. The dependence of the influence of diamond grain size, degree of metallization, type of coatings on the physical and mechanical properties and geometric parameters of coated diamonds was studied.
UDC 546.171.1
V. L. Solozhenko, E. G. Solozhenko (Kyiv) K. Late (Hamburg)
Synthesis of turbostratic carbon nitride.