UDC 620.22:669.018.25
M. O. Bondarenko, S. A. Davydenko*
V. M. Bakul Institute of Superhard Materials, NAS of Ukraine, Kyiv, Ukraine
*bond@ism.kiev.ua
**snesha@ism.kiev.ua
The effect of alloying on the structure and properties of the diamond–(WC–Co) composite. Review (pp. 3-11)
The alloying of the diamond–(WC–Co) composite with the chemical elements Ti, Zr, V, Ta, Nb, Cr, Mo, Ni, Re, Os, Si, B is considered. The effect of each element on the composition, structure and properties of the (WC–Co) matrix, as well as the interfacial surfaces of the diamond–(WC–Co) matrix, is determined. It is shown that complex alloying of the composite with nickel, chromium and silicon is promising.
Keywords: diamond–(WC–Co) composite, diamond, sintered hard alloy, structure, alloying.
UDC 666.295:620.17
S. M. Dub1, *, A. I. Tyurin2, T. O. Prikhna1
1V. M. Bakul Institute of Superhard Materials, NAS of Ukraine, Kyiv, Ukraine
2G. R. Derzhavin Tambov State University, Tambov, Russia
*lz@ism.kiev.ua
Creeping and viscoelasticity of the MAX phase Ti3AlC2 at room temperature (pp. 12-22)
The results of comparative nanoindentation of the MAX phase Ti3AlC2 (nanolayered material), single crystal (001) LiF (elasto-plastic material) and polymer PTFE (visco-elasto-plastic material) are presented. During quasi-static nanoindentation, the hardness and elastic modulus of the samples were determined and significant dissipation of elastic energy was revealed for the MAX phase of Ti3AlC2 under cyclic loading (typical for other nanolaminate materials – graphite, high-temperature superconductors). To determine the viscoelastic characteristics of the MAX phase, the change in the depth of the imprint was recorded for 60 s after rapid unloading of the indenter. The relaxation time for the MAX phase was determined for the first time. Rapid unloading also allowed us to separate the deformation components (elastic, viscoelastic and plastic) in the nanocontact for these materials. If for LiF the fraction of viscoelastic deformation in the total deformation in the contact is negligible (~ 0.1%), then for the MAX phase of Ti3AlC2 and the PTFE polymer it is noticeably higher and is ~ 1 and ~ 17%, respectively.
Keywords: MAX phase, nanoindentation, creep, viscoelasticity.
UDC 666.798. 621.762.4
M. M. Prokopiv, O. V. Kharchenko*
V. M. Bakul Institute of Superhard Materials, NAS of Ukraine, Kyiv, Ukraine
*keramtex@ukr.net
**injenner214@bigmir.net
Structure and properties of tool material from an exothermic mixture of Cr2O3–AlN micropowders obtained by hot pressing (pp. 23-33)
The results of the study of the structure of materials with maximum hardness and crack resistance values obtained by hot pressing mixtures of Cr2O3 micropowders and 15, 25, 35% (by weight) AlN are presented. It is shown that regardless of the composition of the initial mixture, their structure is heterophase of the dispersion-strengthened type. It includes new phases – a matrix of a solid solution of variable composition of the type (Cr1–x–Alх)2О3 (0 < x < 0.9) and dispersed inclusions based on Cr2N. The content and size of the latter increases with an increase in the content of aluminum nitride in the initial mixture. The ratio of Al and Cr in the solid solution depends on the composition of the initial mixture. Aluminum is present in dispersed inclusions based on Cr2N, the content of which increases from 1.8 to 4% (by mass) with an increase from 15 to 35% (by mass) of aluminum nitride in the initial mixture. In this case, the hardness and crack resistance of the material decrease by 2.4 GPa and 1.1 MPa∙m1/2, respectively. It is shown that cutting inserts made of a mixture of Cr2O3–15AlN are competitive in terms of price–quality to the most common inserts made of traditional ceramics CC650 in the conditions of finish turning of carbon steel of the ShKh15 grade (HRC 62).
Keywords: mixtures of Cr2O3, AlN, micropowders, hot pressing, chromium nitride, solid solution.
UDC 621.793.1:620.17:620.18
A. O. Kozak1, *, V. I. Ivashchenko1, **, P. L. Skrynsky1, V. B. Muratov1, V. V. Tetyorkin2, A. Sukach2, O. K. Sinelnychenko1, O. I. Olifan1
1Institute for Problems of Materials Science named after I. M. Frantsevich, NAS of Ukraine, Kyiv, Ukraine
2V. E. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine, Kyiv, Ukraine
*andri.kozak@gmail.com
**ivashchenko@icnanotox.org
Structure and properties of Al–B–Si–C coatings obtained by magnetron sputtering (pp. 34-48)
The structural, mechanical and electro-physical properties of Al–B, Al–B–C and Al–B–Si–C coatings obtained by dual magnetron sputtering of a target made of AlB2, SiC and graphite were studied. The variable parameter was the IAlB current applied to the AlB2 target. The obtained coatings were investigated using X-ray diffraction, infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and by analyzing the results of Knoop hardness measurements and current-voltage characteristics. It was found that all the deposited coatings are X-ray amorphous. FTIR and XPS data show that all the coatings contain B–B, Al–B, B–O and Al–O bonds. When dual sputtering targets with AlB2 and C, AlB2 and SiC, B–C, Si–C and C–C basic bonds are additionally formed in the obtained coatings. It was found that the strengthening coatings with increasing IAlB occurs due to the increase in B–B and Al–B bonds. The current-voltage characteristics of Al–B and Al–B–C coatings indicate that the coatings are disordered semiconductors in which the hopping mechanism of conductivity is implemented.
Keywords: Al–B–Si–C coating, magnetron sputtering, hardness, chemical bond pattern, X-ray structural analysis, current-voltage characteristics.
UDC 666.762.856
V. F. Gorban1, *, A. O. Andreev2, M. O. Krapivka1, V. A. Stolbovoy2, M. V. Karpets1, S. O. Firstov1, A. M. Chykryzhov2
1Institute for Problems of Materials Science named after I. M. Frantsevich NAS of Ukraine, Kyiv, Ukraine
2National Scientific Center “Kharkiv Institute of Physics and Technology”, Kharkiv, Ukraine
*gorban1944@ukr.net
High-entropy superhard coatings based on AlTiCrVNbMo alloy (pp. 49-54)
A coating of high-entropy AlTiCrVNbMo alloy was obtained by ion sputtering in compressed vacuum-arc discharge plasma. The presence of a nanostructured state, which, along with the cluster structure, provides metal coatings with a hardness of 18 GPa. The coating of this alloy, obtained in a nitrogen environment, is a solid solution based on the fcc lattice, and depending on the technological modes, the hardness varies within 28–44 GPa, and the combined elastic modulus is 255–340 GPa. For oxide coatings, the hardness values vary within 33–35 GPa, and the reduced modulus of elasticity – 280–290 GPa. The friction coefficient of this alloy varies depending on the hardness from 0.24 to 0.061.
Keywords: high-entropy alloys, coatings, phase composition, lattice parameter, hardness, reduced modulus of elasticity.
UDC 622.24.051:536.2
V. A. Dutka1, *, E. S. Gevorkyan2, S. R. Vovk2
1V. M. Bakul Institute of Superhard Materials, NAS of Ukraine, Kyiv, Ukraine
2Ukrainian State University of Railway Transport, Kharkiv, Ukraine
*vadutka@ukr.net
Using simulation for homogenization of the temperature field in an Al2O3 billet during hot vacuum pressing (pp. 55-68)
The finite element method was used to perform computer simulation of the temperature field in a hot vacuum pressing (HVP) unit for powder aluminum oxide billets. The temperature dependence of the material properties of the unit elements and contact thermal and electrical resistances are taken into account. The agreement of the obtained calculation results and laboratory temperature measurements indicates the reliability of the model. The results of computer experiments show that by choosing the materials of the HVP unit elements, it is possible to create a practically homogeneous temperature field in the sample at the final stage of the sintering process and significantly reduce energy consumption for the entire sintering process. It has been established that, depending on the equipment scheme of the working cell of the hot-pressing installation, the consideration of contact supports can significantly affect the results of predicting the homogeneity of the temperature field of the sample during the hot-pressing process.
Keywords: modeling, temperature field homogenization, hot vacuum pressing, aluminum oxide.
UDC 539.234: 621.921.34:677.027.232:621.3.032.213.62
Fuming Deng, Cen Hao, Zhenhai Guo, Shuang Wang, Xiang Bo, Zhiyan Zhao
Institute of Super-hard Cutting Tool Materials, China University of Mining and Technology, Beijing, PR China
*dfm@cumtb.edu.cn
Effect of filament carbonization on CVD diamond thick films produced by HFCVD (pp. 69-78)
The hot filament CVD method has many advantages – simple equipment, ease of operation, low cost. This makes it the most widely used method for obtaining thick diamond films. In the work, a tantalum filament was used in a chemical vapor deposition apparatus for carbonization at different temperatures for different times, and the deposition experiments were performed on a molybdenum substrate. SEM and EDS methods were used to observe the surface morphology and analyze the components of the carbonized filament and substrate. The results of the study showed that the duration of the carbonization time can improve the deposition density of the thick diamond film, and the adhesion of the diamond film also increased. The electrical resistance of the filament after carbonization can be used as a criterion to determine whether it is fully carbonized or not.
Keywords: chemical vapor deposition, filament, thick diamond film, carbonization, SEM, diamond nucleation density.
UDC 621.923:621.891
V. I. Lavrinenko
V. M. Bakul Institute of Superhard Materials, NAS of Ukraine, Kyiv, Ukraine
lavrinenko@ism.kiev.ua
The process of abrasive treatment as a frictional interaction: the factor of the presence of sludge on the cutting surface of diamond wheels (pp. 79-86)
The features of sludge particles that arise during grinding of tool materials with diamond wheels are shown. Their elemental composition is given and it is shown in which cases it corresponds or does not correspond to the material being ground. It is investigated where exactly the sludge particles are retained on the cutting surface of the wheel: on the bond or on the grain nah.
Keywords: abrasive treatment, frictional interaction, cutting surface of the wheel, diamond wheels, slurry, wheel bond, diamond grains.
UDC 621.941
L. M. Devin1, *, M. E. Stahniv1, M. P. Mazur2
1V. M. Bakul Institute of Superhard Materials, NAS of Ukraine, Kyiv, Ukraine
2Khmelnytskyi National University, Khmelnytskyi, Ukraine
*ldevin@ism.kiev.ua
Analysis of thermobaric contact phenomena and calculation of temperature fields during finishing turning of titanium alloy VT1-0 by a cutter with a diamond-hard alloy plate (pp. 87-98)
An analysis of contact phenomena and temperature fields was performed and the regularities of temperature changes depending on the cutting speed were established during finishing turning of titanium alloy VT1-0 by a cutter with a diamond-hard alloy plate. New calculated and experimental data on the cutting temperature allowed us to reasonably assign cutting modes limited by temperatures up to 700 °C.
Keywords: turning, titanium alloy, diamond-hard alloy plate, cutting temperature, cutting force.