UDS 549/548.211
V. Kvasnytsya1, *, R. Wirth2, S. Piazolo3, D. E. Jacob3, P. Trimby4
1Institute of Geochemistry, Mineralogy and Ore Formation, National Academy of Sciences of Ukraine, Kyiv, Ukraine
2Helmholtz-Centre Potsdam, German Research Center for Geosciences, Potsdam, Germany
3Australian Research Council Center of Excellence for Core to Crust Fluid Systems and Department of Earth and Planetary Sciences, Macquarie University, North Ryde, Australia
4Australian Center for Microscopy and Microanalysis, The University of Sydney, Australia
*vmkvas@hotmail.com
Surface morphology and structural types of natural impact apographitic diamonds (p. 3-18)
External and internal morphologies of natural impact apographitic diamonds (paramorphoses) have been studied.The (0001) surface morphology of the paramorphoses reflects their phase composition and the structural relationship of their constituent phases.Growth and etch figures together with the elements of crystal symmetry of lonsdaleite and diamond are developed on these surfaces. The crystal size of lonsdaleite is up to 100 nm, and that of diamond is up to 300 nm.Two types of structural relations between graphite, lonsdaleite, and diamond in the paramorphoses are observed: the first type (black, black-gray, colorless and yellowish paramorphoses) – (0001) graphite is parallel to (100) lonsdaleite and parallel to (111) diamond; the second type (milky-white paramorphoses) – (0001) graphite is parallel to (100) lonsdaleite and parallel to (112) diamond.The first type of the paramorphoses contains lonsdaleite–diamond–graphite or diamond–lonsdaleite, the second type of the paramorphoses contains predominantly diamond. The direct phase transition of graphite ® lonsdaleite and/or graphite ® diamond occurred in the paramorphoses of the first type. A successive phase transition graphite ® lonsdaleite ® diamond was observed in the paramorphoses of the second type.The structure of the paramorphoses of this type shows characteristic features of recrystallization.
Keywords: natural impact apographitic diamond, graphite, lonsdaleite, diamond, surface morphology, structure type.
UDC 666.233
AND. M. Panova1, *, G. P. Bogatyreva1, V. I. Zabuga 2, G. G. Tsapyuk2, M. AND. Serga1, O. AND. Trouble 2
1Institute of superhard materials named after IN. M. Bakulya National Academy of Sciences of Ukraine, m. Kyiv, Ukraine
2Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
*annpanova@ukr.net
The Effect of Metal Impurities on the Oxidation of Different Forms of Carbon in the Product of Detonation Synthesis of Diamond (pp. 19-25)
The optimal catalyst for the selective oxidation of the non-diamond component of the product of detonation synthesis of diamond was determined. The phase composition and oxidation resistance of diamond nanopowders extracted by different methods were studied. The presence of residual “non-diamond carbon” in diamond powders extracted by gas-phase oxidation in the presence of cuprous (II) chloride (CuCl2) and their greater resistance to oxidation than those extracted using a mixture of chromic anhydride and sulfuric acid was shown.
Keywords: diamond, detonation synthesis, oxidation, phase composition, catalyst, extraction, carbon.
UDC 004.94:539.893:539.4
S. B. Polotnyak, O. I. Borymsky*
V. M. Bakul Institute of Superhard Materials, NAS of Ukraine, Kyiv, Ukraine
*psb@ism.kiev.ua,
**lab7@ism.kiev.ua
Numerical modeling of the mechanical state of a multi-punch two-stage high-pressure apparatus (pp. 26-39)
Computational schemes and algorithms for numerical modeling by the finite element method of the mechanical state of a multi-punch two-stage high-pressure apparatus (HPA) have been developed. The distribution of the components of the stress tensor, contact and equivalent stresses in the elements of the first and second stages of the HPA when creating a pressure of 18 GPa in the container has been established. The influence of geometric parameters and physical and mechanical properties of the deformed gasket and second-stage punches made of tungsten-cobalt hard alloy of various grades and polycrystalline boron nitride on the limit state of second-stage punches and the level of limit pressures achievable in AHT was investigated.
Keywords: high pressure, high-pressure apparatus, Kawai-type apparatus, punch, stressed state, strength, finite element method.
UDC: 539.32, 548.735, 539.531
V. I. Ivashchenko1, *, S. N. Dub2, **, P. L. Skrynsky1, A. D. Pogrebnyak3, O. V. Sobol4, G. N. Tolmacheva5, V. N. Rogoz3, A. K. Synelnychenko1
1Institute of Materials Science Problems of the National Academy of Sciences of Ukraine,Kyiv, Ukraine
2Institute of superhard materials of the National Academy of Sciences of Ukraine named after IN. N. Bakulya,Kyiv, Ukraine
3 Sumy State University,Sumy, Ukraine
4 National Technical University “Kharkiv Polytechnic Institute”,Kharkiv, Ukraine
5NNC “Kharkiv Physical and Technological Institute, Kharkiv, Ukraine
*ivash@ipms.kiev.ua
**lz@ism.kiev.ua
Nb–Al–N thin films: structural transition from nanocrystalline solid solution nc-(Nb,Al)N to nanocomposite nc-(Nb,Al)N/a-AlN (pp. 40-54)
Conducted structural and mechanical studies properties of thin films of the Nb–Al–N system obtained by magnetron sputtering of niobium and aluminum targets in an Ar–N2 atmosphere. It is shown that with increasing aluminum concentration, the structure of thin films from nanocrystalline turns into a nanocomposite consisting of nanocrystallites of solid solutions in a matrix of amorphous aluminum nitride. The hardness, modulus of elasticity, and yield strength of thin Nb–Al–N films were investigated by the nanoindentation method in the mode of continuous control of contact stiffness. It was established that the transition of the structure of Nb–Al–N thin films from nanocrystalline to nanocomposite leads to an increase in hardness and a decrease in the modulus of elasticity as a result of the formation of a thin amorphous interlayer between the grains of nanocrystallites. The large value of the ratio of hardness to modulus of elasticity for nanocomposite Nb–Al–N thin films indicates that they are a promising material for wear-resistant coatings.
Key words: Nb–Al–N, X-ray structural analysis, thin films, nanoindentation, calculations from first principles.
UDC 621.793: 539.61: 669.018: 620.1
IN. M. Beresnev1,*, S. AND. Klymenko2, O. IN. Sobol3, S. WITH. Grankin1, V. AND. Stolbovoi4, P. IN. Turbin 1, 5, V. Yu. Novikov6, A. AND. Meilekhov3, S. IN. Lytovchenko1, L. IN. Malikov1, 5
1 Kharkiv National University named after IN.N. Karazyna,Kharkiv, Ukraine
2Institute of superhard materials named after IN. N. Bakulya National Academy of Sciences of Ukraine, Kyiv, Ukraine
3National Technical University “Kharkiv Polytechnic Institute”,Kharkiv, Ukraine
4 National scientific center “Kharkov Physical and Technical Institute”,Kharkiv, Ukraine
5Scientific Physics and Technology Center of the MES and NAS of Ukraine,Kharkiv, Ukraine
6 Belgorod State University, Belgorod, Russian Federation
*beresnev-scpt@yandex.ru
The influence of deposition regimes on the structural phase state, hardness, and tribological characteristics of vacuum-arc multilayer coated Mo2N/CrN (p. 55-64)
For vacuum-arc multilayer Mo2N/CrN systems with nanometer-thick layers, a complex study of the influence of technological parameters responsible for the energy state of the deposited particles on the elemental and structural-phase composition, hardness, and tribological characteristics of the formed coatings was carried out. The formation of two structural-phase types in combined nitride layers was established: γ-Mo2N/CrN with isostructural cubic crystal lattices and γ-Mo2N/β-Cr2N with non-isostructural cubic and hexagonal lattices.
Keywords: vacuum-arc deposition method, multi-layer coatings, tribological characteristics.
UDC 621.623
AND. Yu. Filatov*, V. I. Sydorko, S. IN. Kovalev, Yu. D. Filatov, A. G. Wind
Institute of Superhard Materials named after IN. N. Bakulya National Academy of Sciences of Ukraine, Kyiv, Ukraine
*filatov.alexandr@gmail.com
Productivity of polishing of anisotropic monocrystalline materials for optoelectronics (p. 65-76)
As a result of studies of the regularities of the formation of precision surfaces of elements from anisotropic monocrystalline materials for optoelectronic technology, a generalized model of the removal of the processed material during polishing with suspensions of polishing powders was formulated. It was established that the productivity of polishing sapphire planes with different crystallographic orientation increases in the range m<c<a<r with an increase in the volume, surface area, and most probable size of the sludge particles, as well as the energy of dispersion of the material from the processed face.
Keywords: polishing, slime particle, transfer energy.
UDC 621.9.04
AND. AND. Vinogradov
Institute of Superhard Materials named after IN. N. Bakulya National Academy of Sciences of Ukraine, Kyiv, Ukraine
almavin@meta.ua
On the direction of the chip flow during diagonal free cutting of ductile metals (pp. 77-87)
Known methods of determining the angle h of the direction of the chip flow along the front surface of the tool during diagonal free cutting of ductile metals are analyzed. A method of estimating this angle based on chip shrinkage is proposed, based on the determination of the actual (working) front angle gd of the tool in the plane of the normal cutting plane and passing through the direction of movement of the chip. Comparative calculation results are presented and the advantage of the proposed method in terms of simplicity and accuracy of determining the angle h is noted.
Key words: bevel cutting, blade tool, chip formation mechanism, chip flow direction.
UDC 621.921.34–492.544.023.5:539.215
IN.I.Lavrynenko1,, V.G.Poltoratsky1, , M.N.Safonova2,, G.AND.Petasiuk1, A.AND.Devitsky1
1Institute of superhard materials named afterIN.N.Bakulya National Academy of Sciences of Ukraine,Kyiv, Ukraine
2North-Eastern Federal University
named after M.K.Ammosova, g.Yakutsk, Republic of Sakha (Yakutia), Russian Federation
- lavrinenko@ism.kiev.ua
** vg.poltoratsky@gmail.com
*** marisafon_2006@mail.ru
On the question of the use of differently dispersed powders from compacts based on synthetic and natural diamond with a carbon bond in grinding wheels (pp. 88-94)
Possibly studied the use of differently dispersed powders from compacts based on synthetic and natural diamond with a carbon bond in grinding wheels when processing hard alloys. It has been shown that partial (50%) or complete replacement of synthetic diamonds with powders of compacts containing diamond grains with a coating in the form of a super-hard shell made of micropowders of natural Yakut diamonds from cutting production waste with a carbon bond allows to significantly (more than 3 times) increase the wear resistance of diamond grinding wheels.
Key words: carbon bond, Yakut natural diamond micropowders, compacts, grinding powders, grinding wheels, wear resistance.
UDC 661.657.5
IN. WITH. Turkevich*, D. AND. Stratiychuk, D.IN. Turkevich
Institute of Superhard Materials named after IN. M. Bakulya National Academy of Sciences of Ukraine, m. Kyiv, Ukraine
*vturk@ism.kiev.ua
Thermodynamic calculation of the phase diagram of the Si–C system at pressures up to 8 GPa (pp. 95-98)
Using phenomenological thermodynamic models with interaction parameters determined on the basis of experimental data from phase equilibria at high pressures and temperatures, isobaric sections of the phase diagram of the silicon–carbon system at pressures up to 8 GPa were calculated.
Keywords: silicon–carbon system, phase diagram of the system, phenomenological thermodynamics, interaction parameters, Gibbs energy, pressure.