UDC 621.921.34-419:539.533
D. Meng, W. Yue*, F. Lin, C. Wang, Z. Wu (Beijing, China)
*cugbyw@163.com, yw@cugb.edu.cn
Thermal stability of ultrahard polycrystalline diamond composite materials (p. 3–10)
Thermal stability of the ultrahard polycrystalline diamond (UHPCD) composite material developed by the reinforcement of the polycrystalline diamond (PCD) with chemical vapor deposition (CVD) diamond has been investigated in a flow of argon at 1200°C. The indentation, Raman spectra and wear test have been performed to compare hardness, C–C structure and wear resistance of untreated and thermally treated UHPCD. It has been shown that the hardness of CVD diamond in UHPCD reaches 133±7 GPa after high pressure and high temperature, while after thermal treatment the hardness decreases to 109±3 GPa, and the wear resistance of the thermally treated UHPCD decreases from 0.17 to 0.6 mg/km. The narrowing of full width at half maximum and shift of Raman peak to lower frequencies of CVD diamond in thermally treated UHPCD imply a decrease of crystal structural defects and compressive stresses, which results in a drop of the hardness of CVD diamond in a thermally treated UHPCD. The higher wear rate of thermally treated UHPCD is due to the lower hardness.
Keywords: ultrahard polycrystalline diamond, thermal stability, CVD diamond, wear resistance.
UDC 666.3:539.5
AND.P.Fesenko*, V.AND.Chasnyk, O.F. Kolomys, O. M. Kaidash, N. K. Davydchuk, T. B. Serbeniuk, E. F. Kuzmenko, M. P. Gadzyra, O. O. Leshchuk, V. V. Strelchuk,
V. B. Galyamin, S. V. Tkach, E. I. Fesenko, R. S. Shmehera (Kyiv)
Yu. I. Azima (Novomoskovsk, Russian Federation)
Kh. Rekht, Kh. Volstedt (Seddin See, Germany)
*igorfesenko@ukr.net
Study of a ceramic material obtained by free-sintering from the AlN–Y2O3–(SiC–C) powder composition using electron microscopy, Raman spectroscopy, and measurement of thermal conductivity and microwave absorption (pp. 11–20)
Free-sintering of AlN–Y2O3 powder compositions with the addition of SiC–C particles of 50 nm size (agglomerates of 200 nm) produced samples of a composite with a ceramic aluminum nitride matrix. Raman and micro-X-ray phase analyses, as well as measurements of microwave energy attenuation and thermal conductivity, established the presence of a solid solution of SiC in AlN. The main physical and mechanical properties of the obtained AlN–(SiC–C) composites were determined: hardness, thermal conductivity, microwave energy absorption in the frequency band of 9.5–10.8 GHz.
Keywords: composites, aluminum nitride, silicon carbide, microstructure, Raman spectroscopy, thermal conductivity, microwave energy absorption.
UDC 666.233
V. Yu. Dolmatov*, G. K. Burkat (St. Petersburg, Russia)
V. Myllymäki, A. Vehanen (Vantaa, Finland)
*DiamondCentre@mail.ru
Electrochemical chromium-diamond coating (pp. 21–45)
The main regularities and results of applying electrochemical chromium-diamond coatings with detonation nanodiamonds of various types and nanodiamonds of static synthesis are given. The kinetics of the process, the state of nanodiamonds in the universal chromium plating electrolyte, the influence of nanodiamonds on the micro- and macrostructure, the physical-mechanical properties of chrome-diamond coatings, the surface morphology of the coatings, the possibility of using a modified diamond-containing charge are shown. Comparable chromium plating with detonation nanodiamonds of various manufacturers was carried out, microhardness of 1400 kG/mm2 was achieved, wear resistance increased by 6 times, corrosion resistance increased by more than 8 times.
Keywords: detonation nanodiamonds, diamond-containing charge, nanodiamonds of static synthesis, electrochemistry, chrome-diamond coating, universal chromium electrolyte, surface properties.
UDC 621.793:539.61:620.1
AND. D.Pogrebnyak*, B. AND.Postolny, Yu. AND.Kravchenko, A. P.Shipylenko (Sumy)
AT. IN.Sobol, V. M.Beresnev (Kharkiv)
AND. P.Kuzmenko (Kursk, Russian Federation)
*alexp@i.ua
Structure and properties of multi-element superhard coated (Zr–Ti–Cr–Nb)N (pp. 46–59)
The structure and properties of multicomponent nanostructured coated (Zr–Ti–Cr–Nb)N obtained by vacuum-arc deposition are investigated. The thickness of the coating reached 6.2 μm, and the values of hardness and load on the indenter, causing stresses exceeding the cohesive strength of the coating, are H = 43.7 GPa and Lc = 62.06 N, respectively. Structures consisting of three phases of interpenetration with cubic, hexagonal, and tetragonal lattices have been identified in the coatings. The sizes of nanocrystallites range from 4 to 7.3 nm. The results of raster and transmission electron microscopy, energy dispersive X-ray spectroscopy and X-ray structural analysis are given.
Key words: multi-element coatings, nitrides, vacuum-arc evaporation, phase and element composition, microhardness, cohesion, strength.
UDC 621.793.14
IN. WITH. Antonyuk* (Kyiv)
WITH. AT. Bilokin, M. AT. Bondarenko**, Yu. Yu.Bondarenko, Yu. AND. Kovalenko (Cherkasy)
*vp@kpi.ua
**maXXium@rambler.ru
For Application of wear-resistant coatings on silicon probes for atomic force microscopy by thermal vacuum evaporation (pp. 60–69)
The possibility of modifying silicon probes of an atomic force microscope with a thin wear-resistant carbon coating is shown, which leads to an improvement in their operational properties (reduces the probability of scanning artifacts by 20–22%, increases the service life by 45–55%). Optimal modes of application of such coatings by thermal evaporation in vacuum with subsequent low-energy electron beam microprocessing are proposed. The quality of the applied coating is checked, which established a decrease in the subroughness of the probe surface by 15–25 times, as well as an increase in the microhardness and wear resistance of these coatings by 1.1–1.35 times.
Keywords: silicon probe, atomic force microscopy, thin coating, electron beam micromachining, wear resistance.
UDC 621.762.242: 669.27
I. V. Andreev (Kyiv)
aigor@i.ua
Some aspects of viscoplastic flow of products made of heavy tungsten-based alloys (pp. 70–75)
The results of studies on the distortion of the geometric shape of samples of a tungsten-based alloy with a nickel bond are presented. A multi-stage shape change of the samples due to the liquation of the liquid phase in the material during sintering in a continuous multi-zone furnace was revealed.
Keywords: tungsten alloy, shape change, sintering, liquation of the liquid phase.
UDC 941.025.7:621.9.011
WITH. An. Klymenko, A. WITH. Manokhin, S. AND. Klymenko* (Kyiv)
*atmu@ism.kiev.ua
Investigation of the parameters of the contact zone and the stress on the front surface of the tool, equipped with PSTM based on KNB, during turning of hardened steel (pp. 76–84)
A complex of experimental studies of the geometric parameters of the contact zone of the tool with the processed material was completed. Chip shrinkage, cutting forces, and temperature on the front surface of a tool equipped with polycrystalline superhard materials based on cubic boron nitride during finish turning of hardened steel were determined. Estimated normal and tangential stresses in the area of contact of the tool with the chip. It is shown that 70 and 30% of the normal force acting on the front surface of the cutter is accounted for by the plastic and elastic contact areas of the tool with the chip, respectively.
Key words: instrument, polycrystalline superhard material, cubic boron nitride, hardened steel, tension, contact zone.
UDC 622.23.051.7
AT. AND. Zanevsky, S. AND. Ivakhnenko, G. D. Ilnytskaya, A. P. Zakora, R. K. Bohdanov* (Kyiv)
AND. AND. Karakozov, M. WITH. Popova (Donetsk)
*dep13@ism.kiev.ua
**almis28@ism.kiev.ua
Production of coarse-grained, high-strength diamond grinding powders for use in drilling tools (pp. 85–96)
The cultivation technology was studied and large monocrystalline synthetic diamonds with high strength, uniformity in strength and heat resistance were obtained. The construction of a drill bit equipped with such diamond crystals has been developed. The results of production tests of experimental drill bits are given.
Key words: single crystals, synthetic diamonds, strength, thermal stability, specific magnetic susceptibility, single-layer diamond drill bits, mechanical drilling speed.
UDC 548.52:679.822
P. IN. Konevsky*, R. THERE ARE. Brodsky, L. AND. Litvinov (Kharkov)
*kopamas@gmail.com
Impact fragmentation of sapphire (p. 97–100)
Samples of vacuum-annealed sapphire, hardened sapphire, and Gorilla Glass glass were tested by the impact fracture method. It was established that the sizes of the formed fragments of sapphire samples are 10–100 times larger than those of glass fragments at the same impact energy.
Key words: sapphire, destruction, fragmentation, strength.