UDC 669.275:621.762.5
B. S. Lakshmi Prasad1, A. Raja Annamalai2, *1School of Mechanical Engineering, VIT University, Vellore 632014, India
2Centre for Innovative Manufacturing Research, VIT University, Vellore 632014, India
*raja.annamalai@vit.ac.in
Tungsten heavy alloys with molybdenum, Y2O3 and lanthanum. A review (p. 3-22)
The consolidated results of studies of tungsten doping with various metals and compounds (Ni, Fe, Cu, Mo, Y2O3, La2O3) are presented, the advantages of doping with regard to its conditions, microwave and plasma sintering techniques are shown. It has been found that the mechanical properties of tungsten are significantly improved by the addition of the above elements. The resulting heavy fame tungsten can be used to protect against nuclear radiation.
Keywords: tungsten, sintering, microstructure, microhardness, tensile strength, yield strength, elongation, viscosity, molybdenum, lanthanum oxide, yttrium oxide.
UDC 621.921.34-492.2:535.37
AT. G. Lysenko1, *, V. I. Hrushko1, E. I. Mytskevich1, H. D. Ilnytskaya1, A.Yu.Boyaryntsev2, Yu. D. Onufriev2, V.F. Popov3, L. G. Levchuk3, N.M.Kazyuchits4, M. WITH. Rusetskyi4, V. IN. Lysakovsky 1, S. AND. Ivakhnenko1
1Institute of superhard materials named after IN. N. Bakulya National Academy of Sciences of Ukraine, Kyiv, Ukraine
2Institute of scintillation materials of the National Academy of Sciences of Ukraine,Kharkiv, Ukraine
3 National Science Center Kharkiv Physical and Technical Institute,Kharkiv, Ukraine
4Belarusian State University, Minsk, Belarus
*ismdiadep@gmail.com
Luminescent and radiation characteristics of monocrystalline diamond powders (p. 23-32)
Different types of luminescence (photoluminescence, cathodoluminescence, X-ray luminescence) in the range from 360 to 900 nm of single-crystal diamond powders with grain sizes from 125/100 to 250/200, divided into different groups by the degree of perfection of the crystal structure and values of magnetic susceptibility, were studied. At room temperature, the H3 glow of the diamond defect prevailed in all groups of crystals, and nickel centers dominated the cathodoluminescence spectra at the temperature of liquid nitrogen. Samples of composite scintillators were made using selected diamonds and polysiloxane elastomer Sylgard 184, and their radiation resistance was studied. Compared to the standard YSO:Ce scintillator, the radiation resistance of diamond composite scintillators to irradiation with fast electrons has been established.
Keywords: monocrystalline diamond powders, photoluminescence, cathodoluminescence, X-ray luminescence.
UDC 621.921.34:661.65:537.31
D. Prikhodko1, 2, *, S. Tarelkin1, 3, V. Bormashov1, 2, 4, A. Golovanov1, 2, M. Kuznetsov1, D. Teteruk1, N. Kornilov1, A. Volkov1, A. Buga1, 2
1Technological Institute for Superhard and Novel Carbon Materials, Troitsk, Moscow, Russia
2Moscow Institute of Physics and Technology, Moscow Region, Russia
3National University of Science and Technology MISiS, Moscow, Russia
4The All-Russian Research Institute for Optical and Physical Measurements (VNIIOFI), Moscow, Russia
*dmprikhodko@gmail.com
Low temperature thermal conductivity of heavily boron-doped synthetic diamond: Influence of boron-related structure defects (p. 33-41)
Thermal conductivity of single-crystal boron-doped diamonds (BDD) with ~ 2×1019 cm–3 (~ 120 ppm) and 5×1019 cm–3 (~ 300 ppm) boron content was studied by a steady-state method in a temperature range of 20–400. K. The obtained data were analyzed within Callaway model framework. The values of dislocation density obtained from best fit of experimental data and from density of etch pits measuring were compared. Their discrepancy suggests presence of some other boron-related defects in crystal lattice.
Keywords: boron-doped diamond; thermal conductivity; HPHT; dislocation density.
UDC 621.723.7
O. K. Porada*, V. I. Ivashchenko, L. A. Ivashchenko, A. O. Kozak, O. O. Sytikov
Institute of Problems of Materials Science named after I. M. Frantsevich NAS of Ukraine, Kyiv, Ukraine
*o-porada@ukr.net
Plasmochemical equipment for the deposition of nanocomposite nanolayered films (pp. 42-50)
The basic principles of creating a vacuum universal station VUP-5(M) and further using plasmachemical equipment for the deposition of thin-film, including nanolayered, materials from vapors of usually liquid precursors are presented. The method can be classified as deposition in a gaseous environment activated by radiofrequency plasma of the E-type in systems with a continuous flow (open tube method). The equipment is universal in terms of the choice of precursor and has a sufficient set of technological parameters, which makes it possible to deposit a wide range of coatings with a controlled thickness from 1 to 2000 nm. Plasma chemical equipment advantageously complements the set of technical capabilities of VUP-5(M) and expands its operational characteristics without significant intervention in the design.
Keywords: thin solid films, nanocomposite and nanolayered films, plasma chemical equipment, VUP-5(M) , PECVD, ALD, technological parameters.
UDC 666.762.856
IN. F. Gorban1, *, A. A. Andreev2, A. M. Chikryzhov2, M. V. Karpets1, N. AND. Krapyvka1, A. IN. Dolomanov2, A. AND. Ostroverkh 2
1Institute of Problems of Materials Science named after I.N. Frantsevich National Academy of Sciences of Ukraine,Kyiv, Ukraine
2 National Science Center “Kharkov Physical and Technical Institute”,Kharkiv, Ukraine
*gvf@ipms.kiev.ua
Preparation and physical and mechanical properties of a high-entropy oxide based on an equiatomic CrFeCoNiMn alloy (pp. 51-57)
Physico-mechanical and X-ray phase studies of a high-entropy oxide coating obtained by cathodic sputtering of a multicomponent CrFeCoNiMn alloy in the plasma of a compressed vacuum-arc gas discharge are carried out. It is shown that the hardness of the high-entropy oxide coating reaches 27 GPa with a modulus of elasticity of 270 GPa, and after annealing at a temperature of 1100 °C for 300 minutes in air, it decreases to 17 GPa. The coefficient of friction of the coating at low sliding speeds is 0.045–0.132, depending on its hardness.
Key words: oxide coating, high-entropy alloy, vacuum-arc compressed discharge, hardness, oxidation, coefficient of friction.
UDC 621.793.002.3-419
IN. Yu. Dolmatov1,*, G. K. Burkat2, D. IN. Rudenko1, I. AND. Dyakov3
1Federal state unitary enterprise “Special design and technological bureau “Technologist”, St. Petersburg, Russia
2St. Petersburg State Technological Institute (Technical University), St. Petersburg, Russia
3Tambov State Technical University (TGTU), Tambov, Russia
*diamondcentre@mail.ru
Development of the process of electrochemical deposition of nickel-diamond coating with modified phosphorus DNA (pages 58-65)
The use of phosphorus-modified detonation nanodiamonds during electrochemical nickel plating allows to increase the microhardness of the coating up to 660 kg/mm2, wear resistance up to 8 times, and corrosion resistance up to 70 times when using a standard nickel plating electrolyte.
Keywords: electrochemical deposition, nickel, detonation nanodiamonds, phosphorus, modified nanodiamonds, microhardness, wear resistance.
UDC 621.762
I. Yu. Trosnikova*, P. I. Loboda
National Technical University of Ukraine “Kyiv Polytechnic Institute named after. Igor Sikorsky”, Kyiv, Ukraine
*irina2510@ukr.net
The influence of the conditions of production on the microstructure, phase composition and properties of the eutectic alloy of the wc–w2c system (pp. 66-70)
The influence of the conditions of production on the microstructure, phase composition and properties of the eutectic alloy of the wc–w2c system – relite, which is widely used as a surfacing material for strengthening high-wear parts, was established. The methods of scanning electron microscopy, X-ray phase and durometric analyses revealed that the increase in mechanical properties is satisfactorily correlated with the decrease in the ratio between the number of W2C, WC and WC1–x phases, the thickness of the phase layers in the grains and the elongation of the latter.
Keywords: tungsten carbides, gas environment, centrifugal spraying, cooling rate, stress-strain state.
UDK 629.715.33/6121.7.62
AND. WITH. Bychkov1, *, A. IN. Kondratiev2, **1 State scientific research expert and forensic center of the Ministry of Internal Affairs of Ukraine, Ukraine, Kyiv
2 National Aerospace University named after N.THERE ARE. Zhukovsky “Kharkov Aviation Institute”, Ukraine, Kharkov
*asbychkov85@gmail.com
**a.kondratiev@khai.edu
Criterion evaluation of the improvement of operational characteristics of details of aircraft structures with gas-thermal coatings (p. 71-79)
A block diagram is presented, reflecting the advantages of gas-thermal methods of applying protective coatings and the main factors affecting the structure and properties of the coatings. The method of preliminary establishment of priority on the effectiveness of concrete coatings and the gas-thermal sputtering method corresponding to them is proposed. The effect of mechanical processing on the operational properties of coated parts is taken into account. It is proposed to implement a criterion assessment of the improvement of the operational characteristics of aircraft structure parts with gas-thermal coatings within the framework of a conceptual approach based on the use of an integral efficiency criterion, which includes individual, group, and complex components.
Key words: protective coatings, gas-thermal methods, efficiency criteria, operational characteristics, details of aircraft structures.
UDC 621.9.025.7
Yang Xuefeng1, *, Deng Fuming1, **, Deng Wenli1, Xi Peiyao1, Tan Chuxuan1, Lu Xuejun1,2
1Institute of Superhard Cutting Tool Materials, China University of Mining and Technology (Beijing), Beijing, China
2Beijng Dimengjingrui Science and Technology Co., Ltd., Beijing, China
*381281866@qq.com
**dfm@cumtb.edu.cn
Optimization of designing on cutter parameters of PCD saw blades by simulation analysis (стр. 80-89)
The cutter parameters of PCD circular saw blades play a decisive role in the wood cutting process, they directly affect the machining surface quality and tool life. Simulation analysis of the cutting stress and deformation of PCD wood circular saw blades with different cutter parameters is carried out using the finite element method. The results show that the maximum shear stress of the PCD saw blade in cutting process are all in a safety range with safety coefficient of about 3.5–4.0, and the maximum displacement of PCD saw blades are about 4.8–4.9 μm in the axial direction and about 10 μm in radial and rotation directions. It was found that the best cutter parameters of the PCD circular saw blades are rake angle γ = 15° and rear angle α = 15°, in which the relative low stress of 58.9 MPa and relative smaller displacement of can be achieved.
Keywords: polycrystalline diamond (PCD), wood circular saw, finite element analysis (ANSYS), cutter parameters.