UDC 534.631: 539.32: 539.42: 658.562
L. M. Devin1,, T. O. Prikhna1,*, P. P. Barvitsky1, S. V. Rychev1, M. V. Karpets1, 2, V. E. Moshchil1, M. O. Tsisar1, S. S. Ponomarev3, O. V. Prysyazhna1, A. S. Lokatkina1
1V. M. Bakul Institute of Superhard Materials, NAS of Ukraine, Kyiv, Ukraine
2I. M. Frantsevich Institute of Problems of Materials Science, NAS of Ukraine, Kyiv, Ukraine
3V. E. Lashkarev Institute of Semiconductor Physics, NAS of Ukraine, Kyiv, Ukraine
*ldevin@ism.kiev.ua
**prikhna@ukr.net
Physical and mechanical characteristics of impact-resistant ceramics under static and dynamic loading (pp. 3-20)
The characteristics of the structure and the results of a comprehensive study of the mechanical properties of B4C and AlB12 ceramic samples by ultrasonic, static and dynamic methods, as well as composites obtained from mixtures of B4C + 5–25% (by mass) SiC and AlB12 + 10–20% (by mass) TiC, manufactured by hot pressing at 30 MPa in the temperature range of 1950–2200 °C, are presented. The level of achieved mechanical characteristics makes the use of the developed composite materials in armor protection elements and other products subjected to significant dynamic loads promising. It is shown that for determining the strength under dynamic loading, disk samples of brittle materials with a diameter of 5–15 mm can be used. Methods developed at the V. M. Bakul Institute of Superhard Materials of the NAS of Ukraine were used to study the manufactured ceramic materials.
Keywords: methodology for determining elastic characteristics, speed of sound, mechanical characteristics, static and dynamic methods, impact-resistant materials, refractory borides and carbides, X-ray phase analysis, structural analysis, Rietveld method, raster scanning electron microscopy.
UDC 621.762.5:661.657.5
Peicheng Mo1,2,3, *, Chao Chen1,2,3, Chuan Chen4, Yi Wu4, Jiarong Chen1,2,3, Feng Lin1,2,3
1China Non Ferrous Metal (Guilin) Geology and Mining Co, Ltd, Guilin, Guangxi, P. R. China
2Guangxi Key Laboratory of Superhard Material, Guilin, Guangxi, P. R. China
3National Engineering Research Center for Special Mineral Material, Guilin, Guangxi, P. R. China
4Guilin University of Technology, Material Science and Engineering School, Jiangan Road, Guilin, P. R. China
*2393707540@qq.com
Effect of Temperature on Sintering of PCNB with Ti–Si3N4–AlN–Y2O3 Additives (pp. 21-31)
Using X-ray diffraction, field scanning electron microscopy microscopy and a universal mechanical testing machine, the effect of different sintering temperatures on the composition, microstructure, porosity and mechanical properties of polycrystalline cubic boron nitride (PCBN) obtained at high temperature and ultrahigh pressure was studied. It was shown that the main phases were cBN, α-Si3N4, β-Si3N4, TiN and TiB2. The CBN grains are interconnected by the reaction product. With increasing sintering temperature, the hardness of the sample increases, and its flexural strength first increases and then decreases. When the sintering temperature was 1600 °C, PCNB showed the best comprehensive characteristics, the hardness and flexural strength were 32.2 GPa and 1022.5 MPa, respectively.
Keywords: PCNB, high temperature-ultrahigh pressure, mechanical properties; binding agent.
UDC 620.22-621.921.34
V. A. Mechnyk1,, M. O. Bondarenko1, V. M. Kolodnitsky1,*, V. I. Zakiyev2, I. M. Zakiyev2, E. S. Gevorkyan3, V. A. Chyshkala4, M. O. Kuzin5
1V. M. Bakuly Institute of Superhard Materials, NAS of Ukraine, Kyiv, Ukraine
2National Aviation University, Kyiv, Ukraine
3Ukrainian State University of Railway Transport, Kharkiv, Ukraine
4V. N. Karazin Kharkiv National University, Kharkiv, Ukraine
5Lviv Branch of Dnipro National University of Railway Transport named after Acad. V. Lazaryan, Lviv, Ukraine
*vlad.me4nik@ukr.net
**vasylkolod56@gmail.com
The effect of CrB2 on the microstructure, properties and wear resistance of a sintered composite and diamond retention in the Fe–Cu–Ni–Sn matrix (pp. 32-51)
The effect of CrB2 addition (in the range from 0 to 8% (by weight)) on the formation of the structure of the diamond–matrix transition zone and matrix material, microhardness, elastic modulus, diamond grain fixation in the Fe–Cu–Ni–Sn matrix material and wear resistance of sintered composite diamond-containing materials (CBM) was investigated using the powder metallurgy method. Micromechanical and tribological tests were performed on composite samples with a diameter of 10 mm and a thickness of 5 mm. It was established that the structure of the transition zone significantly depends on the CrB2 content in the composite and has a different nature than the structure of the matrix material. The structure of the transition zone of the KAM based on the matrix 51Fe–32Cu–9Ni–8Sn consists of the phases Cu, a-Fe and Ni3Sn with graphite inclusions, and with the addition of CrB2 – of the a-Fe phase and carbide layers Fe3C, Cr7C3, Cr3C2 without graphite inclusions.
It is shown that the hardness and elastic modulus of the matrix material of sintered composites increase linearly with increasing CrB2 concentration in their composition, and the wear rate decreases. Adding 2% (by m(as) CrB2 to the 51Fe–32Cu–9Ni–8Sn composite resulted in an increase in hardness from 4.475 to 7.896 GPa and an increase in the modulus of elasticity from 86.6 to 107.5 GPa and a decrease in the wear rate from 21.61×10-6 to 10.04×10-6 mm3 N-1 m-1. The mechanism for increasing the mechanical properties and wear resistance of KAM samples containing the CrB2 additive is the grinding of the matrix phases of iron and copper from 5-40 to 2-10 μm and the binding of carbon released during graphitization of diamond grains into nano-sized carbides Fe3C, Cr7C3, Cr3C2. This, in turn, increases the ability of the matrix material to retain diamond grains from falling out during the operation of the KAM. The low values of mechanical and tribological properties of the initial (51Fe–32Cu–9Ni–8Sn) composite are explained by the coarse-grained structure and the formation of graphite inclusions in the diamond–matrix transition zone, which causes its premature destruction and the fallout of diamond grains from the KAM matrix.
Keywords: composite, diamond–matrix transition zone, composition, concentration, structure, hardness, elastic modulus, wear rate.
UDC 621.36
O. Ya. Pak*, T. Yu. Yakich, A. I. Kokorina, E. B. Akimova
National Research Tomsk Polytechnic University, Tomsk, Russia
*ayapak@tpu.ru
Obtaining crystalline phases of tungsten carbide by the influence of atmospheric electric arc plasma on tungsten oxide (pp. 52-60)
The possibility of obtaining powders based on tungsten carbides in atmospheric electric arc plasma is shown under the condition of using its oxide as the initial source of tungsten. The dependence of the phase composition of the product of vacuum-free arc synthesis on the amount of supplied energy is established. Tungsten carbide is represented both by particles with sizes of the order of tens of micrometers and by particles of the nanoscale range with a maximum distribution from 5 to 15 nm.
Keywords: tungsten carbide, electric arc plasma, arc discharge energy, atmospheric plasma, vacuum-free method.
UDC 620.178:621.793.1
V. F. Gorban1, *, A. O. Andreev2, V. O. Stolbovoy2, S. O. Firstov1, V. K. Shkolny1
1I. M. Frantsevich Institute for Problems of Materials Science, NAS of Ukraine, Kyiv, Ukraine
2National Scientific Center “Kharkiv Institute of Physics and Technology”, Kharkiv, Ukraine
*gorban1944@ukr.net
High-temperature hardness of multilayer vacuum-arc metal–metal nitride coatings (pp. 61-66)
The effect of temperature on the hardness of thick (up to 100 μm) multilayer metal–metal nitride coatings was determined. It was shown that the nature of the change in hardness with temperature is individual for each of the tested multilayer coatings. The hardness of composite multilayer coatings largely depends on the ratio of each component in the coating. For a composite multilayer metal–metal nitride coating based on the most refractory metal molybdenum with a component ratio of ~ 60/40, the hardness at room temperature and a load of 1 kg reaches 22 GPa, and at 900 °C – 5.0 GPa.
Keywords: multilayer coatings, temperature, hardness, Young’s modulus.
UDC 544.723.5
A. P. Karmanov1, V. Yu. Dolmatov2,*, L. S. Kocheva3, N. G. Rachkova1, N. I. Bogdanovich4, N. S. Almazova2
1Komi Institute of Biology of the Ural Branch of the Russian Academy of Sciences, Syktyvkar, Russia
2Federal State Unitary Enterprise “Special Design and Technological Bureau “Technologist”, St. Petersburg, Russia
3Komi Institute of Geology of the Ural Branch of the Russian Academy of Sciences, Syktyvkar, Russia
4Northern (Arctic) Federal University named after M.V. Lomonosov, Arkhangelsk, Russia
*diamondcentre@mail.ru
Detonation nanodiamonds as adsorbents of uranium and thorium (pp. 67-79)
The sorption properties of carbon nanomaterials with different contents of the detonation nanodiamond fraction for radionuclides 238U and 232Th were studied. The adsorption-desorption indices of U and Th in aqueous media were determined. The correlations between the surface structure indices of the samples and their sorption capacity were determined. It was found that the highest indices of irreversible adsorption of U and Th is characterized by a sorption material with the highest possible content of detonation nanodiamonds.
Keywords: detonation nanodiamonds, adsorption, radionuclides, uranium, thorium, surface-porous properties, IR spectra.
UDC 620.793.8:669.721.5:620.193
Jie Chen1, Hui Song2,*, Guang Liu1, Ziyun Zheng1, Jiayun Tang1, Lang Cui1
1Inner Mongolia Metallic Materials Research Institute, Ningbo, P. R. China
2Key Laboratory of Marine Materials and Related Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, P. R. China
*songhui@nimte.ac.cn
Improvement of wear resistance and corrosion properties of magnesium alloy by applying WC–17Co nanocoating by cold spraying method (pp. 80-90)
The improvement of wear resistance and corrosion resistance of magnesium alloys by coating processes was investigated for their application to reduce the weight of mechanical engineering components. The WC–17Co nanocoating applied and cold spraying on commercial magnesium alloy AZ80 with different spray speeds. The WC–17Co coating had an extremely dense structure and bonded well to the magnesium alloy substrate when the spray speed was selected to be 80 and 40 mm/s. The coating prepared at a deposition speed of 40 mm/s (C40) had the highest microhardness and fracture toughness. Ball–disk wear test showed that the WC–17Co coating could significantly improve the wear resistance of the magnesium alloy. The wear rate of the C40 coating was 8.2×10–7 mm3/(N×m), while the magnesium alloy exhibited the highest wear rate of 6.8×10–4 mm3/(N×m). WC–17Co coating reduces the corrosion current density of magnesium alloy, the best corrosion resistance was also provided by C40 coating.
Keywords: cold spraying, magnesium alloy, wear, corrosion, WC–17Co.
UDC 621.919
S. E. Sheikin1, *, O. V. Grushko2, V. V. Melnychenko1, S. F. Studenets1, I. Yu. Rostotsky1, D. V. Efrosinin1, Ya. V. Melnychenko1
1V. M. Bakul Institute of Superhard Materials, NAS of Ukraine, Kyiv, Ukraine
2Vinnytsia National Technical University, Vinnytsia, Ukraine
*sheykin2003@ukr.net
On the contact interaction of carbide deforming broaches with the workpiece during the formation of grooves in the holes of tubular products (pp. 91-101)
The zone of contact interaction of the tool with the workpiece during the formation of longitudinal grooves on the inner cylindrical surface of tubular parts was studied. It was established that the occurrence of seizing during the formation of grooves is most influenced by the degree of plastic deformation of the processed material. The MFE calculation established the level of maximum contact stresses in the zone of interaction of the tool with the processed product in the range from 5σ0.2 (3.15 GPa) to 10.8σ0.2 (6.5 GPa).
Keywords: technological lubricant, deforming broaches, carbide deforming broaches, seizing, contact pressure.