UDC 621.762.55
T. O. Solovyova*, E. V. Solodkyi, P. I. Loboda
National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”, Kyiv, Ukraine
*tsolov@iff.kpi.ua
Spark-plasma sintering of metal-ceramic composite Cu–(LaB6–TiB2) and its physical and mechanical properties (pp. 3–12)
A metal-ceramic composite Cu–(LaB6–TiB2) was obtained by the method of spark-plasma sintering. The microstructure, phase composition, mechanical properties and electrical resistance were studied. An effective method of reinforcing the copper matrix–ceramic reinforced particles LaB6–TiB2 interface was proposed and implemented. It is shown that the densification of the metal-ceramic composite using LaB6–TiB2 particles with bare fibers allows to increase the strength of the material almost twice. In addition, the use of reinforced ceramic particles provides electrical conductivity at the level of the best materials of resistance welding electrodes (88% IACS).
Keywords: metal-ceramic composite, spark-plasma sintering, electrical conductivity, strength during compression.
UDC 539.21
V. E. Diyuk1, O. V. Ishchenko1, O. B. Loginova2, *, L. M. Melnyk3, L. D., Kisterska2, V. V. Garashchenko2, S. O. Lysovenko2, O. A. Beda1, N. A. Tkachuk3, O. Yu. Shevchenko3, O. V. Turchun3
1Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
2V. M. Bakul Institute of Superhard Materials, NAS of Ukraine, Kyiv, Ukraine
3National University of Food Technologies, Kyiv, Ukraine
*pol@ism.kiev.ua
Restoration of Shungite Adsorption Properties (pp. 13–22)
The surface state of a natural mesoporous carbon material – shungite, was studied using electron microscopy, X-ray phase and micro-X-ray spectral analyses. The ability to restore the adsorption properties of shungite for the extraction of higher alcohols and other impurities from aqueous-alcoholic solutions was studied using thermogravimetry and IR spectroscopy. The main difference between the absorption spectra of the spent shungite and the original sample is the absence of absorption by hydroxyl groups (3380 cm–1) and a significant decrease in the contribution of the component at 1170 cm–1, which corresponds to the absorption of phenolic groups. It has been shown that heat treatment in argon, water vapor and in a CO2 environment leads to almost complete removal of sorbed organic substances and regeneration of the adsorption properties of shungite, the latter method being more economically justified.
Keywords: natural sorbents, mesoporous materials, shungite, adsorption complexes, functional surface groups.
UCD 669.275:539.27
Xiaokun Yuan
College of Materials Science and Engineering, Beijing University of Technology, Beijing, China
yuanxiaokun@bjut.edu.cn
Effect of different binder phases on the Σ2 grain boundary plane distribution in cemented carbides (p. 23–32)
For WC–6 wt% Co and WC–6 wt% Ni composites, and by using five parameter analysis method as a new approach, the geometric and crystallographic features of carbide/carbide boundaries have been characterized. Two most frequently occurring WC/WC boundaries are 90° twist boundaries about [10-10] (Σ2 boundaries) and 27.8° twist boundaries about [0001] (Σ13a boundaries), the Σ2 boundary populations vary with binder phase types, and carbide crystals are most frequently terminated by (0001) and (10-10) surfaces, such preference does not significantly alter if Σ2 boundaries are partitioned.
Keywords: Σ2 grain boundary, cemented carbide, binder phase, electron backscattered diffraction, five parameter analysis.
UCD 621.892.7:622.24.05
Lanlan Xie 1, *, Liyi Chen 1, Xiaolin Huang 2
1State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Environment and Civil Engineering, Chengdu University of Technology, Chengdu, China
2Institute of Exploration Technology, Chinese Academy of Geological Sciences, Chengdu, China
*xllcdut@foxmail.com
Effect of graphite addition on impregnated diamond bit properties (pages 33–45)
Graphite was used as a solid lubricant to reduce thermal damage in diamond bit when drilling without coolant. Graphite was added to the bit matrix material to reduce friction coefficient and heat. The influence of content, granularity, and surface metallization of graphite on the mechanical properties and dry friction properties of the matrix, as well as the effect of diamond lifetime in the working layer were studied. Results showed that the hardness, bending strength, and friction coefficient of the matrix gradually decreased with the increase in graphite concentration. Meanwhile, the abrasion loss decreased first and then increased, and the lifetime of diamond in the working layer gradually increased. With the decrease in graphite granularity, the bending strength and friction coefficient of matrix gradually decreased, whereas the hardness, abrasion loss of matrix, and diamond lifetime in the working layer gradually increased. After surface metallization of graphite, the hardness, bending strength, friction coefficient, and abrasion loss of matrix x increased, whereas the lifetime of diamond in the working layer decreased. This study lays a foundation for drilling without water.
Keywords: graphite, diamond bit, mechanical properties, dry friction properties, lifetime of diamond.
UDC 621.941:536.483
Anshuman Das1, Saroj Kumar Patel2, Bibhuti Bhusan Biswal1, Sudhansu Ranjan Das3, *
1Department of Industrial Design, National Institute of Technology, Rourkela, Odisha, India
2Department of Mechanical Engineering, National Institute of Technology, Rourkela, Odisha, India
3Department of Production Engineering, Veer Surendra Sai University of Technology, Burla, Odisha, India
*das.sudhansu83@gmail.com
Machinability investigation and cost estimation during finish dry hard turning of AISI 4340 steel with untreated and cryo treated cermet inserts (pages 46–66)
For higher tool life of cutting inserts cryogenic treatment is considered as the most prominent method but no substantial researches have been found concerning the impact of cryogenic treatment on cermet inserts especially in hard turning. Therefore, in the present experimental investigation, the comparative assessment of various responses such as cutting force, flank wear, crater wear, chip morphology and surface roughness were carried out during machining of hardened steel with both untreated and cryo treated cermet in hard turning erts under dry cutting condition. Finally, the input variables were optimized using Response surface methodology (RSM) to evaluate the tool life for the economic analysis. The experimental result demonstrated that the uncoated deep cryo treated with tempered cermet insert delivered better results in comparison to other cermet inserts. According to cost analysis, uncoated and deep cryo treated with tempered cermet insert was found to be the most economical among other cermet inserts at the optimum cutting condition.
Keywords: hard turning, cryogenic treatment, machinability, cost analysis.
UCD 621.9.025.7:661.657.5
M. Ociepa*, M. Jenek, E. Feldshtein, K. Leksycki
Institute of Machine Construction and Operations Engineering, University of Zielona Gora, Zielona Gora, Poland
*m.ociepa@ibem.uz.zgora.pl
The phenomenon of material side flow during finish turning of EN X153CrMoV12 hardened steel with tools based on polycrystalline cubic boron nitride (p. 67–75)
The study presents the results of an analysis of the phenomenon of material side flow during finish turning of EN X153CrMoV12 (H12MF GOST 5950-2000) tool steel hardened to 63±2 HRC with cutting tools made of polycrystalline composites based on polycrystalline cubic boron nitride. For an uncoated wedges of CBN 7025 the material side flow occurred for the entire range of tested cutting feed. For a CBN 8120 wedges with a TiA1N coating the side flow was observed exclusively for the cutting feed of f = 0.2 mm/rev. The researched phenomenon did not occur on the surfaces finished with a CBN 7015 tool coated with TiN.
Keywords:polycrystalline cubic boron nitride, PCBN, hardened steel, finish turning, surface layer, material side flow.
UDC 621.923.02
Ya. O. Shakhbazov1, *, V. V. Shirokov1, V. O. Fedorovych2
1Ukrainian Academy of Printing, Lviv, Ukraine
2National Technical University “Kharkiv Polytechnic Institute”, Kharkiv, Ukraine
*shah-nika@ukr.net
Establishment of technological conditions for dressing grinding wheels with a diamond tool (pp. 76–82)
Based on theoretical and experimental studies, a mode of diamond dressing of grinding wheels on a ceramic bond for conditions of micro- or macro-destruction of abrasive grains has been established. This allows determining technological dressing modes for rough and finish grinding operations. Calculation equations are proposed for determining the depth of dressing of grinding wheels for different types of their wear.
Keywords: grinding, grinding wheel, wear, dressing, diamond crystal.
UDC 621.923
O. O. Pasichny, V. I. Lavrinenko*
V. M. Bakul Institute of Superhard Materials, NAS of Ukraine, Kyiv, Ukraine
*ceramic@ism.kiev.ua;
**lavrinenko@ism.kiev.ua
The influence of wave deformation of the cutting surface of diamond wheels in the circular direction on the roughness parameters of the processed surface (pp. 83–86)
A study was conducted to suppress wave deformation of the cutting surface of a diamond wheel by dressing with a diamond pencil. It was shown that in this case, the roughness parameters of the surface processed by such a wheel change, namely: the height parameters decrease, the step of micro-roughnesses and the indicators of the relative reference length of the profile increase.
Keywords: diamond wheel, cutting surface, wave deformation, surface roughness parameters, wheel dressing.
UDC 621.762; 621.893
A. A. Adamovsky*, A. D. Kostenko
Institute of Problems of Materials Science named after I. N. Frantsevich NAS of Ukraine, Kyiv
*adamovskyi@ipms.kiev.ua
Coefficient of friction of natural diamond on materials based on cubic boron nitride (pages 87–89)
It is reported that the dominant influence on the value of the friction coefficient of the diamond pyramid based on the samples of St the phase composition of the materials of the contacting pairs is shown by the BN-based hard-hard materials.
Key words: friction pair, superhard materials, coefficient of friction, dry friction.
UDC 66.045.34+621.763
AND. AND. Shulzhenko1, *, A. N. Sokolov1, **, L. Yavorska2, ***, V. G. Gargin1, E.F. Kuzmenko1
1Institute of superhard materials named after IN.N.Bakulya of the National Academy of Sciences of Ukraine
2The Institute of Advanced Manufacturing Technology, Krakow, Poland
*alexshulzhenko35@gmail.com
**kybor@ism.kiev.ua
***lucyna.jaworska@ios.krakow.pl
Thermal conductivity of copper with the addition of n-layer graphene (pages 90–93)
The influence of the addition of n-layer graphene on the thermal conductivity of copper samples sintered at high pressures and temperatures was studied. It is shown that the addition of graphene Gn(4) to copper powder in the amount of 0.2–0.4% (by mass) allows to increase the thermal conductivity of the samples by 14–37%.
Key words: n-layer graphene, copper, pressure, temperature, thermal conductivity.