UDC 546.281’261:54.057:621.785.3
AND.I.Pak*, M. AND. Rudmin, G.I.Mamontov, O.AND. Bolotnikova
Tomsk Polytechnic University, Tomsk, Russia
*ayapak03@gmail.com
Electroarc synthesis and purification from carbon impurities of cubic silicon carbide in the air atmosphere (pp. 3–12)
A method of obtaining the cubic phase of silicon carbide β-SiC by annealing in air is presented. Due to the high resistance of β-SiC to oxidation in air, it was possible to purify it during the combustion of the graphite phase in the temperature range ~ 700–900 °С. According to the data of X-ray diffractometry, a powder material with a β-SiC content close to 99% (by volume) was obtained, while, according to the results of scanning electron microscopy, β-SiC is characterized by a wide (from ~ 0.1 to ~ 10 μm) particle size distribution and a typical crystal shape for this phase. The method of electric arc synthesis of β-SiC and its subsequent purification to commercial purity was implemented for the first time in an air environment without the use of protective inert gases.
Keywords: silicon carbide, electric arc synthesis, thermal analysis, air environment.
UDC 661.657.5:539.533
Rui Shi, Dong Wang, Li-Hua Gan*
School of Chemistry and Chemical Engineering, Southwest University, Chongqing, China
*ganlh@swu.edu.cn
A potential superhard material m-BCN (pages 13–20)
We here propose a new superhard material m-BCN with comparable Vickers hardness to cBN by the use of first-principles calculations. The calculations show that the mentioned m-BCN is a thermodynamically and kinetically stable semiconductor. Hydrostatic calculation shows that it is anisotropic and its incompressibility is very close to c-BN. Structural analysis shows that its excellent mechanical properties and thermodynamic stability are inherited from diamond and cBN. These results provide a new clue to find a new superhard phase.
Keywords: m-BCN, mechanical properties, electronic structure, Vickers hardness, hydrostatic calculation
UDC 621.785
IN. G. Khyzhnyak, T. V. Loskutova*, T. Yu. Kalashnikov,
O. I. Mykolaychuk
National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”, Kyiv, Ukraine
*losktv1@bigmir.net
Obtaining multilayer coatings from the gas phase with the participation of TiC, TiN compounds on VK8 hard alloy (pp. 21–32)
The phase and chemical composition, structure, thickness, microhardness, and operational properties of the VK8 hard alloy with multilayer coatings obtained by diffusion titanating, titanoaliding, nitro-titanating, and nitro-titanoaliding methods were studied. The last two methods combine nitriding at a temperature of 540 °C for 20 h with subsequent titanating or titanoaliding. It was established that the composition of TiN, TiC layers formed during nitro-titanium alidation performs barrier functions during chemical-thermal treatment. The formed barrier completely inhibits the penetration of aluminum and oxygen into the base and promotes the formation of the AlCoTi2 compound on the surface, the microhardness of which, due to the dissolution of nitrogen, reaches 12.6 GPa. The maximum microhardness for TiC layers is 31.0–35.5 GPa, for TiN – 20.0–21.5 GPa. The resistance of nitro-titanium alidated multifaceted non-regrinding carbide plates VK8 during cutting of U8A steel increased by 10.5 times compared to the original one.
Keywords: multilayer coatings, titanation, titanation, nitro-titanium alidation, nitro-titanium alidation, nitride, structure, microhardness, wear resistance.
UDC 621.921.34-419:536.421.5
Baoyan Liang1, 2, Danhui Han1, 2, Wangxi Zhang1, 2, *
1Materials and Chemical Engineering School, Zhongyuan University of Technology, Zhengzhou, China
2National and Local Joint Laboratory of Engineering of Diamond Technology, Zhengzhou, China
*zwxlby@126.com
Fabrication and wear performance of (Cu–Sn) solution/TiCxbonded diamond composites (p. 33–39)
The Cu(Sn)–TiCx bonded diamond composites were prepared by in situ reaction sintering of Cu, Ti2SnC and diamond powders. Effect of Ti2SnC content on the phase composition, microstructure and grinding properties were studied. The result shows that Ti2SnC was decomposed to TiCx and Sn. And then, Sn atom dissolved into the crystal lattice of Cu and formed Cu(Sn) solution. The rich C formed at the interface between diamond and the matrix. Excess Ti2SnC inhibited the formation of Cu solid solution and reacted with Cu to form Cu3Sn. Additionally, its matrix was mainly composed of TiCx with better wear resistance, which can obviously improve the grinding performance of the composites. The grinding ratio value of copper-diamond composite was only 132. The grinding ratio value of the composite contained higher Ti2SnC content in the raw materials was 636.
Keywords: reaction synthesis, diamond, Cu, TiCx.
UDC 669.25’27
AND. AND. Matveychuk*, S. AND. Davydenko
Institute of Superhard Materials named after IN. N. Bakulya National Academy of Sciences of Ukraine, Kyiv, Ukraine
*o.matviychuk@i.ua
About the interaction of races blue cobalt with polycrystalline tungsten monocarbide (pages 40–45)
The interaction of molten cobalt with hot-pressed and synthesized polycrystalline WC samples was investigated. It is shown that polycrystalline WC-mesoelements are promising for obtaining mesostructural WC–Co hard alloys by liquid-phase sintering.
Key words: sintered hard alloys, tungsten carbide, mesostructure.
UDC 544.7:661.872
AT. AND. White1, O. IN. Ishchenko2, V. THERE ARE. Diyuk2, L. D. Kisterska 3, O. B. Loginova3, V. M. Weaver3
1Lviv National University named after Ivan Franko, m. Lviv, Ukraine
2Kyiv National University named after Taras Shevchenko, m. Kyiv, Ukraine
3Institute of superhard materials named after V. M. Bakulya NAS of Ukraine, Kyiv, Ukraine
*pol@ism.kiev.ua
Modification of carbon fabric with metal nanoparticles for microbial fuel cells (pp. 46–55)
An electron microscopic study of the state (size distribution and elemental composition) of Fe and Fe–Co-based nanoparticles on the surface of carbon fiber deposited from colloidal solutions, chemical deposition, and direct dispersion in plasma was carried out. The operation of carbon fibers modified with metal nanoparticles as anodes in a laboratory two-chamber microbial-anode cell of a fuel cell based on the bacteria Desulfuromonas acetoxidans was investigated. The feasibility of practical use of Fe nanoparticles in the anodes of microbial fuel cells was proven.
Keywords: Fe and Fe–Co nanoparticles, modified carbon fibers, microbial fuel cell.
UDC 621.941
N. THERE ARE. Stakhnyv, L. N. Devin*, A. AND. Bochecka, A. AND. Osadchy, S. N. Nazarchuk, S.IN. Rychev
Institute of Superhard Materials named after IN. N. Bakulya National Academy of Sciences of Ukraine, Kyiv, Ukraine
*ldevin@ism.kiev.ua
Investigation of the influence of the phase composition of cutting inserts made of diamond–tungsten carbide nanocomposite on the process of fine turning of aluminum and brass alloys (pp. 56–66)
The influence of the phase composition of cutting inserts made of diamond–tungsten carbide nanocomposite on the cutting forces, the coefficient of friction in the cutting zone, and the acoustic emission signal in the process of fine turning of aluminum and brass alloys was studied. It was established that the content of tungsten in the initial mixture in the amount of 30–40% (by mass) ensures the sintering of the composite of the cutting plate with the most favorable phase composition for turning aluminum and brass alloys.
Key words: clean turning, acoustic emission, aluminum alloy, brass, processing modes, diamond–tungsten carbide composite, high-pressure sintering.
UDC 621.7.015:539.43:621.941.025.7
K. WITH.Barandych, S. P.Vysloukh, V. WITH.Antoniuk*
National Technical University of Ukraine “Ihor Sikorskyi Kyiv Polytechnic Institute”, Kyiv, Ukraine
*vp@kpi.ua
Ensuring the cyclic durability of parts during finish turning with a cubic boron nitride tool (pp. 67–78)
A study of the relationship between the state of the surface layer of a part made of 40X steel, formed during finish turning with a tool made of dense modified boron nitride, and its cyclic durability is presented. For the first time, a mathematical model was obtained that shows the dependence of cyclic durability on the modes of turning parts with a cubic boron nitride tool. The possibility of finish turning of critical parts operating under the influence of loads varying in magnitude and direction is substantiated.
Keywords: cyclic durability, surface layer quality, finish turning, cubic boron nitride.
UDC 621.762:621.921.34
A. I. Sagradyan1, *, S. G.Agbalyan2, A.M.Martirosyan2, N. AND. Ordyan1, Kh. IN. Poghosyan2
1Armenian State Pedagogical University named after Kh. Abovyana, g.Yerevan, Armenia
2National Polytechnic University of Armenia, Yerevan, Armenia
*sahradyanartak34@aspu.am
Increasing the service life of a diamond tool for processing non-metallic materials (pages 79–86)
The mechanism of genesis and formation of coated Ti–Cr on HSD 90 synthetic diamond powders was revealed and investigated. The matrix metal forming the coating as a whole is Ti, and Cr is the alloying element. The heat resistance of metallized diamond powders was investigated by the method of derivatography. It was established that the resistance to oxidation of metallized diamonds increases by 40°C compared to the initial ones, and mutual diffusion takes place at the coating-bond boundary.
Key words: coating, diamond, microcracks, diffusion, metallization.
UDC 621.762:666.3–13
AT.N.Kaidash*, V.WITH.Turkevich, M.AND.Marynych, I.P.Fesenko, V.WITH.Belovol, V.N.Weaver
Institute of Superhard Materials named after IN. N. Bakulya National Academy of Sciences of Ukraine, Kyiv, Ukraine
*ivv@ism.kiev.ua
Corrosion resistance of hot-pressed ceramic system B4C–VC (pp. 87–91)
Corrosion resistance, structure, and physical and mechanical properties of hot-pressed B4C–VC composites were studied. Received materials, perspectives ny for use as end seals in chemical production.
Keywords: composite material, B4S, VC, anodic potentiodynamic curve, corrosion resistance.
UDC 621.91.02:539.89
K. V. Slipchenko*, I. A. Petrusha, D. A. Stratiychuk, V. Z. Turkevich
V. M. Bakuly Institute of Superhard Materials, NAS of Ukraine, Kyiv, Ukraine
*kateslipchenko@gmail.com
The effect of VC–Al additive on the wear resistance of cBN-based composites (pp. 92–93)
Wear resistance of the cBN–VC–Al system material for cutting tools under conditions of continuous high-speed turning of AISI 316L stainless steel will be reported.
Keywords: high pressure, turning, sintering, boron nitride.