UDC 666.3:539.5
T. O. Prikhna*, T. B. Serbeniuk, V. B. Sverdun, V. I. Chasnyk, M. V. Karpets, T. V. Basyuk (Kyiv)
Dellikh Ya. (Jena, Germany)
*prikhna@mail.ru
Regularities of the Formation of the Structure of Ceramic Materials Based on AlN–SiC (pp. 3–11)
Composite materials based on AlN–SiC were obtained by the free-sintering method. It was established that during the formation of the AlN–SiC–Y3Al5O12 structure, yttrium aluminum garnet is located along the boundaries of SiC and AlN grains, preventing the mutual solubility of AlN–SiC. It was determined that an increase in the amount of SiC from 20 to 50% (by mass) leads to a change in the parameters a (from 0.49821 to 0.49837 nm) and c (from 0.5046 to 0.498 nm) of the AlN crystal lattice and to an increase in the absorption capacity of the composite from 8.8 to 31.4 dB/cm (at frequencies of 9.5–10.5 GHz).
Keywords: composite, AlN, SiC, microstructure, absorption capacity, crystal lattice parameters, absorber material.
UDC 621.793.1:620.17:620.18
A. O. Kozak, V. I. Ivashchenko, O. K. Porada, L. A. Ivashchenko, O. K. Sinelnychenko, S. M. Dub*, O. S. Lytvyn, I. I. Timofeeva (Kyiv)
G. M. Tolmacheva (Kharkiv)
*ivash@ipms.kiev.ua
**sergey-dub@bigmir.net
The effect of nitrogen flow on the properties of thin amorphous Si–C–N films obtained by magnetron sputtering (pp. 12–24)
Thin Si–C–N films were deposited on silicon substrates by reactive magnetron sputtering of a silicon-carbon target at a constant current and at different ratios of nitrogen FN2 and argon FAr flows. X-ray diffraction, infrared spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy, and nanoindentation were used to study the structure, chemical bonds, surface morphology, and mechanical properties of the obtained Si–C–N films. It was found that all the obtained Si–C–N thin films are X-ray amorphous. The surface roughness of the films weakly depends on FN2 and is 0.23–0.28 nm. An increase in FN2 leads to the appearance and strengthening of Si–N and C–N bonds and the weakening of Si–C bonds. The thin films contain a small amount of oxygen, which forms Si–O and C–O bonds, and the latter weaken with increasing FN2. The nanohardness of amorphous SiC thin films is 23 GPa, and the elastic modulus is 207 GPa. The nanohardness and elastic modulus of Si–C–N thin films decrease with increasing nitrogen flow, which is associated with the weakening of Si–C bonds.
Keywords: thin Si–C–N films, magnetron sputtering, nanoindentation, chemical bonds, X-ray photoelectron spectroscopy.
UDC 621.793:539.61:620.1
A. D. Pogrebnyak*, A. A. Demyanenko, A. V. Pshik, Yu. A. Kravchenko (Sumy)
O. V. Sobol’, V. M. Beresnev (Kharkov)
H. Amekura, K. Kono, K. Oyoshi, Y. Takeda (Tsukuba, Japan)
I. A. Podchernyaeva (Kyiv)
*alexp@i.ua
Structural features and physical and mechanical properties of amorphous coated AlN–TiB2–TiSi2 (pp. 25–38)
A coating of the AlN–TiB2–TiSi2 system was obtained by the method of target magnetron sputtering. When the coating is exposed to high temperatures (900 and 1300 °C), its crystallization with the formation of crystallites with a size of 11−25 nm is observed. The amorphous structure is promising when using such coatings as diffusion barriers both as independent elements and as a contact layer in multi-layer wear-resistant coatings. The use of the resulting composite as an effective protective coating for the cutting tool will increase its wear resistance by more than 30% at a temperature in the cutting zone of up to 1300°C.
Key words: nanocomposite coating, magnetron sputtering, phase and element composition, microhardness, annealing.
UDC 669.295.539.121.537.534
IN. WITH. Nemchenko, V. M. Beresnev* (Kharkov)
WITH. AND. Klymenko**, I. AND. Podchernyaeva (Kyiv)
P. V. Turbin, A. AND. Andreev (Kharkov)
*beresnev-scpt@yandex.ru
**atmu@ism.kiev.ua
Wear resistance of the multicomponent coating system (Ti–Zr–Hf–V–Nb–Ta)N at elevated temperature (pages 39–44)
The results of research on the coating made of a high-entropy alloy based on the (Ti–Zr–Hf–V–Nb–Ta)N system obtained by vacuum-arc deposition are presented. The properties of the coating were investigated using the methods of raster electron microscopy and X-ray diffraction analysis. It has been established that increasing the temperature of tribological tests in air from 20 to 460 °C contributes to the increase in wear resistance of the coating.
Key words: wear resistance, coefficient of friction, multi-element nitride coating, tribological tests.
UDC 549.21:542.943
Kh. I. Kabel*, Ah. A. Farag, E. M. Elnaggar, A. G. Al-Gamala (Cairo, Egypt)
*drkhalid1977@yahoo.com
Improvement of graphene oxide characteristics depending on base washing (p. 45–54)
Graphene oxide (GO) has been synthesized using Hummer’s method. This oxidation process decorates the graphene sheets by different types of functional groups, yet the harsh oxidation condition leads to introduce many of carbonaceous fragments, which decreasing GO efficiency in many ways, affected its applications. The synthesized GO has been washed by 10 M NaOH to produce (GOn). After that quality enhancement of GO has been studied by several analyses; the introduced hydroxyl and carboxyl groups into few-layer graphene (FLG) surface have been determined by Fourier transform infrared spectra (FTIR). Raman spectroscopy analysis identified the defect degree and the transition of graphite from a crystalline to an amorphous structure and vice versa. The interlayer spacings of FLG and GOn were investigated by X-ray diffraction (XRD) and the thermal stability of as-received and modified materials were examined by thermal gravimetric analysis (TGA). The morphological structure was characterized by scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). The various investigations confirmed that the properties of GO were improved by neutralization impact, which may pave the way to new developments in the GO-based applications.
Keywords: oxidation, graphene oxide, few-layer graphene, carbonaceous fragments, electrostatic stabilization.
UDC 535.377:661.883.1
E. Rubio (Puebla, México)
D. Mendoza (Estado de México, México)
V. Rodríguez (Pachuca, Hidalgo, México)
V. M. Castaño* (Santiago de Querétaro, México)
*meneses@unam.mx
Sulfur-enhanced thermoluminescence of g-radiated zirconia (p. 55–61)
Sulfur-modified zirconia with various S contents have been characterized and analyzed for potential applications in dosimetry. The thermoluminescent signal induced by gamma radiation in pure zirconia and sulfated zirconia in the tetragonal phase has been considered. Experimental results show that the thermoluminescent glow peak depends on both the crystalline structure and sulfate concentration and that the response is linear for an ample range of irradiation.
Keywords: thermoluminescence, gamma radiation, pure zirconia, sulfated zirconia, crystalline structure.
UDC 679.822:[539.533+539.56]
AND. IN. Voloshyn, E. F. Dolzhenkova*, L. AND. Litvinov (Kharkov)
*dol@isc.kharkov.ua
Anisotropy of the processes of deformation and destruction of the sapphire surface (pp. 62–68)
Peculiarities of the processes of destruction of corundum single crystals during abrasive wear and scratching depending on the crystallographic orientation and technological factors are studied.The mechanical properties of sapphire and Gorilla Glass are compared.
Key words: sapphire, grinding, sclerometry, anisotropy, abrasive dispersion.
UDC 621.923.6
AND. AND. Adamovsky*, N. WITH. Zyukin (Kyiv)
*adamovskyi@ipms.kiev.ua
Adhesive-active correction of abrasive and diamond grinding wheels (pp. 69–74)
A high-modulus diamond hard alloy composite material, on the basis of which diamond pencils are made, has been developed. Tests have shown that new pencils are 2.5 times better than standard pencils. A tool for precision grinding of diamond wheels is proposed, selective destruction of thin surface layers of diamond grain is investigated. It is shown that after editing, diamond wheels provide less roughness of polished surfaces.
Keywords: abrasives, grain, correction, abrasive instrument.
UDC 621.919
WITH. THERE ARE. Sheykin* (Kyiv)
AND. M. Pogrelyuk** (Lviv)
D. AND. Sergach (Kyiv)
*sheykin2003@ukr.net
**pohrelyuk@ipm.lviv.ua
Modification of the working surface of titanium components of friction units (pp. 75–82)
The possibility of using titanium in friction units of artificial joints has been studied. The tribotechnical characteristics of the titanium/hyrulene friction pair have been investigated, the technology of cold surface plastic deformation (CSPD) of spherical parts and thermal diffusion nitriding of spherical heads made of pure titanium for human hip joint endoprostheses has been developed. It has been shown that the preliminary CSPD provides an increase in the level of near-surface hardening, which is reflected in the shift of the microhardness distribution curves along the intersection of near-surface hardened layers to the region of higher hardness values. The near-surface (at a depth of ~5 μm) microhardness of the nitrided layer of rolled samples is significantly (up to 30%) higher than the microhardness of untreated CPPDs.
Key words: friction, nitriding, setting, deformation, chirulene.
UDC 621.762
AND. P. Wozniakovsky*, A. IN. Smirnov, B. AND. Fedorov, A. Kh. Khoreva, F. AND. Shumylov (St. Petersburg)
*voznap@mail.ru
Geometric characteristics of detonation carbon particles according to X-ray small-angle scattering data (pp. 83–91)
For the first time, the morphology of the product of the detonation decomposition of mixed explosives under conditions of negative oxygen balance – detonation carbon – was studied by the method of small-angle X-ray scattering. It is shown that detonation carbon is a discrete set of particles having the shape of a flattened ellipsoid of rotation (with an axis ratio of 1:20…1:25), formed by an amorphous carbon component, which includes at least one particle of the crystalline phase – detonation diamond. The geometric dimensions of the particles were calculated for the first time.
Keywords: detonation synthesis, detonation carbon, detonation nanodiamonds, method of small-angle X-ray scattering.