Кафедра "Матеріалознавство"

Постійне посилання колекціїhttps://repository.kpi.kharkov.ua/handle/KhPI-Press/6927

Офіційний сайт кафедри http://web.kpi.kharkov.ua/mtrlvd

Від 2007 року кафедра має назву "Матеріалознавство", первісна назва – "Металознавство та термічна обробка металів".

Кафедра "Металознавство та термічна обробка металів" створена у 1932 році. Першим її очільником став доктор технічних наук, професор Олександр Володимирович Терещенко.

Кафедра являє собою одну із найстаріших в політехнічному інституті з підготовки інженерів-технологів-дослідників. Своїми науковими дослідженнями. з початку своєї діяльності, кафедра сприяла розвитку та удосконаленню технологій термічної та хіміко-термічної обробки деталей на підприємствах України».

Кафедра входить до складу Навчально-наукового інституту механічної інженерії і транспорту Національного технічного університету "Харківський політехнічний інститут".

У складі науково-педагогічного колективу кафедри працюють: 1 доктор технічних наук, 9 кандидатів технічних наук, 3 кандидата фізико-математичних наук, 1 доктор філософії; 1 співробітник має звання професора, 8 – доцента, 1 – старшого наукового співробітника.

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Structure, Adhesion Strength and Corrosion Resistance of Vacuum Arc Multi-Period NbN/Cu Coatings
(2020) Postelnyk, H. O.; Sobol, O. V.; Chocholaty, O.; Zelenskaya, G. I.
The influence of deposition modes on the phase-structural state, corrosion resistance, and adhesive strength of vacuum-arc multi-period NbN/Cu coatings is studied. It was found that in thin layers (about 8 nm, in a constant rotation mode), regardless of the change in the pressure of the nitrogen atmosphere, a metastable δ - NbN phase forms (cubic crystal lattice of the NaCl type). At a layer thickness of ~ 40 nm or more, a phase composition changes from the metastable δ - NbN to the equilibrium ε - NbN phase with a hexagonal crystal lattice. In the presence of the ε - NbN phase in the niobium nitride layers, the highest adhesive strength is achieved with a value of LС5 = 96.5 N. Corrosion resistance tests have shown that for all the studied samples the corrosion process has mainly an anodic reaction. The highest corrosion resistance was shown by coatings obtained at a pressure of 7·10-4 Torr, with the smallest bias potential of -50 V and the smallest layer thickness; with a thickness of such a coating of about 10 microns, its service life in the environment of the formation of chloride ions is about a year.
The Use of Negative Bias Potential for Structural Engineering of Vacuum-Arc Nitride Coatings Based on FeCoNiCuAlCrV High-Entropy Alloy
(Sumy State University, 2018) Sobol, O. V.; Andreev, A. A.; Gorban, V. F.; Meylekhov, A. A.; Postelnуk, A. A.; Stolbovoy, V. A.; Zvyagolskiy, A. V.
The effect of negative bias potential (Ub = – 40, – 110, and – 200 V) upon the deposition of multielement coatings on their composition, structure, and mechanical properties was studied. It is shown that when using a high-entropy multielement (of 7 elements) FeCoNiCuAlCrV alloy, it is possible to obtain a single-phase nitride (FeCoNiCuAlCrV)N. Nitride has an fcc crystal lattice (structural type NaCl). It has been established that with an increase in Ub in the structural state occurs transition from practically nontextured (polycrystalline) to the preferential orientation of the growth of crystallites with the [111] texture axis (at Ub = – 110 V) and [110] (at Ub = – 200 V). This is accompanied by a decrease in the lattice period, as well as a decrease in hardness and modulus of elasticity. For coatings (FeCoNiCuAlCrV) N, the highest hardness of 38 GPa is achieved by using the smallest (– 40 V) bias potential during the deposition process. It is shown that to achieve high hardness at high Ub it is necessary to increase the content in the highentropy alloy of elements with high nitride-forming ability.
Structure and Properties of Vacuum-arc Coatings of Chromium and Its Nitrides Obtained under the Action of Constant and Pulse High-voltage Bias Potential
(Sumy State University, 2017) Sobol, O. V.; Postelnyk, A. A.; Mygushchenko, R. P.; Al-Qawabeha, Ubeidulla F.; Tabaza, Taha A.; Al-Qawabah, Safwan M.; Gorban, V. F.; Stolbovoy, V. A.
To reveal the regularities of structural engineering of vacuum-arc coatings based on chromium and its nitrides, the influence of the main physicotechnological factors (the pressure of the nitrogen atmosphere and the bias potential) in the formation of coatings was studied. It was discovered that during the deposition of chromium coatings the formation of the texture axis [100], as well as the macrodeformation of compression is happening. The supply of a high-voltage negative pulse potential to the substrate increases the mobility of the deposited atoms and leads to relaxation of the compression deformation. As the pressure increases from Torr, the phase composition of the coatings changes: Cr (JCPDS 06-0694) → Cr2N(JCPDS 35-0803) → CrN(JCPDS 11-0065). The supply of high-voltage pulses leads to the formation of a texture of crystallites with parallel growth surfaces planes having d ≈ 0.14 nm. The structure obtained by pulsed high-voltage action makes it possible to increase the hardness of the coating to 32 GPa and reduce the friction coefficient to 0.32 in the "chromium nitride-steel" system and to 0.11 in the "chromium nitride-diamond" system. The results obtained are explained from the viewpoint of increasing the mobility of atoms and the formation of cascades of displacements when using an additional high-voltage potential in the pulse form during the deposition of chromium-based coatings.
Mixing on the Boundaries of Layers of Multilayer Nanoperiod Coatings of the TiNх/ZrNх System: Simulation and Experiment
(Sumy State University, 2017) Sobol, O. V.; Meylekhov, A. A.; Mygushchenko, R. P.; Postelnyk, A. A.; Sagaidashnikov, Yu. Ye.; Stolbovoy, V. A.
Using the complex of methods for attestation of the structural state in combination with computer simulation and measurement of mechanical properties (hardness), the influence of the period Λ on the mixing process on the interlayer boundaries of multilayer coatings TiNх/ZrNх is studied. The formation of two phases (TiN and ZrN) with one type of crystal lattice (structural type NaCl) is identified in the layers of multiperiodic compositions TiNx/ZrNx with a period of Λ = 20 ... 300 nm. At Λ = 10 nm, the formation of a solid solution (Zr, Ti)N, as well as a small volume of the TiN phase is revealed on XRD spectras. The presence of TiN component is due to the larger initial value of the layer based on titanium nitride. To explain the results obtained, the results of computer simulation of damage at the atomic level during bombardment by ions accelerated in the Ub field are used. The critical thickness of mixing (about 7 nm) in the TiNx/ZrNx system is determined upon condition that Ub = – 110 V. It is established that a decrease in the period from 300 to 20 nm leads to increase in hardness. The highest hardness of 44.8 GPa corresponds to the superhard state. It is established that the critical thickness of radiation-stimulated defect formation has a significant effect on the stress-strain state and hardness of coatings with a small Λ ≈ 10 nm. In this case, relaxation of the stress-strain compression state occurs and the hardness decreases. However, the formation of a solid solution, while retaining part of the unreacted layer of titanium nitride at Λ = 10 nm, makes it possible to obtain an ultrahigh (44.8 GPa) hardness of the coating.
Influence of the Bias Potential and the Pressure of the Nitrogen Atmosphere on the Structure and Properties of Vacuum-arc Coatings Based on the AlCrTiZrNbV High-entropy Alloy
(Sumy State University, 2018) Sobol, O. V.; Andreev, A. A.; Gorban, V. F.; Postelnyk, A. A.; Stolbovoy, V. A.; Zvyagolskiy, A. V.
The effect of the constant bias potential (Ub) supplied to the substrate upon condensation and pressure of the nitrogen atmosphere (PN) on the elemental composition, growth morphology, texture, and physical-mechanical characteristics of vacuum-arc (AlCrTiVZrNb)Nx coatings is studied. It is established that with increasing Ub from – 110V to – 200V, the axis of preferential growth of crystallites of the fcc phase from [100] to [110] changes. Such a change is accompanied by a decrease in the hardness (H) and the ratio H/E (where E is the modulus of elasticity). The conditions for the formation of the preferential orientation of the crystallites (axial texture) of vacuum-arc (AlCrTiVZrNb)Nx coatings and the influence of texture on mechanical properties are discussed. It was established that the change in PN in the range Torr basically allows to vary the degree of filling of the coating with nitrogen atoms. Based on the revealed regularities, the conditions for achieving high hardness for vacuum-arc coatings of nitrides AlCrTiVZrNb high-entropy alloy are substantiated. Because of the presence in the alloy of elements with a relatively low heat of nitride formation, in order to achieve high hardness, it is necessary to use deposition conditions with relatively low energy of bombarding atoms. The use of a low Ub = –110 V at the highest pressure Torr allows achieving an superhard state with a hardness of 44 GPa.
The Influence of Layer Thickness and Deposition Conditions on Structural State of NbN/Cu Multilayer Coatings
(Sumy State University, 2019) Sobol, O. V.; Andreev, A. A.; Meylekhov, A. A.; Postelnyk, A. A.; Stolbovoy, V. A.; Ryshchenko, I. M.; Sagaidashnikov, Yu. Ye.; Kraievska, Zh. V.
The influence of the main physical and technological factors of structural engineering (layer thickness, nitrogen atmosphere pressure and bias potential) on the structural-phase state of the NbN/Cu coatings was studied. It was established that with an increase in the thickness of niobium nitride layers from 8 to 40 nm (in the NbN/Cu multilayer composition), the phase composition changes from the metastable NbN (cubic crystal lattice, NaCl structural type) to the equilibrium ε-NbN phase with a hexagonal crystal lattice. At low pressure PN = 7·10 – 4 Torr in thin layers (about 8 nm thick), regardless of the Ub, the NbN phase is formed. The reason for the stabilization of this phase can be the uniformity of the metallic fcc crystal lattice of the δ-NbN phase with the Cu crystal lattice. As the pressure increases from РN = 7·10 – 4 Torr to 3·10 – 3 Torr, a more equilibrium ε-NbN phase with a hexagonal crystal lattice is formed. An increase in the bias potential during deposition from – 50 V to – 200 V mainly affects the change in the preferred orientation of crystallite growth. In thin layers of the NbN phase (about 8 nm), a crystallite texture with the [100] axis is formed. In layers with a thickness of 40-120 nm, crystallites of the NbN phase are predominantly formed with a hexagonal (004) plane parallel to the growth plane. At the greatest layer thickness (more than 250 nm), the NbN phase crystallites are predominantly formed with a (110) hexagonal lattice plane parallel to the growth plane. The results obtained show great potential for structural engineering in niobium nitride when it is used as a constituent layer of the NbN/Cu multilayer periodic system.
The Effect of Constant and High Voltage Pulse Bias Potentials on the Structure and Properties of Vacuum-Arc (TiVZrNbHf)Nₓ Coatings
(Sumy State University, 2018) Sobol, O. V.; Postelnyk, A. A.; Mygushchenko, R. P.; Gorban, V. F.; Stolbovoy, V. A.; Zvyagolskiy, A. V.
The effect of constant (Ub) and high voltage pulse (Uip) bias potentials supplied to the substrate during condensation, on the structure and properties of vacuum-arc (TiVZrN-Hf)Nх coatings has been studied. It has been determined that the number and size of the drop phase decreases with increasing Ub. The use of Uip promotes a more uniform growth in the coating volume. It is shown that due to the increase of Ub from 0 to 200 V in nitride coatings of high entropy alloys, it is possible to change the growth texture [100] to [111]. This results in increased hardness from 32 GPa to 49 GPa. The supply of high voltage potential in a pulse form leads to a relative decrease in the average size of crystallites and the formation of a bi-texture state. Conditions and mechanisms of the preferential crystallites orientation (axial texture) of vacuum arc (TiVZrNbHf)Nх coatings and texture influence on mechanical properties have been discussed.
The Influence of Layers Thickness on the Structure and Properties of Bilayer Multiperiod Coatings Based on Chromium Nitride and Nitrides of Transition Metals Ti and Mo
(Sumy State University, 2018) Sobol, O. V.; Meylekhov, A. A.; Mygushchenko, R. P.; Postelnyk, A. A.; Tabaza, Taha A.; Al- Qawabah, Safwan M.; Gorban, V. F.; Stolbovoy, V. A.
The influence of the layers thickness of bilayer multi-period coatings of the CrNx/MoNx and CrNx/TiNx systems on their phase-structural state, substructure, stress-strain state and mechanical properties was studied using methods of precision structural analysis in combination with computer simulation of implantation processes during particle deposition. It is established that a two-phase structure of CrN and-Mo2N phases of the structural type NaCl is formed in the multi-period coatings of the CrNx/MoNx system with a nanometer thickness of the layers. Because of the small difference in periods (less than 0.5 %) for Λ = 20 nm, the layers form a coherent interlayer interface. The use of small Ub – 20 V during deposition makes it possible to avoid significant mixing at interlayer (interphase) boundaries even at the smallest Λ = 10 nm. Nitride layers formed under conditions of vacuum arc deposition are under the action of compressive stresses. In the СrNх/TiNх system, because of the relatively large discrepancy between periods (more than 2.5 %), during the formation of the same structural components in the layers (CrN and TiN phases of the structural type NaCl), the epitaxial growth with period adjusting does not occur, even for the smallest Λ = 10 nm. The action of the deformation factor at the interphase boundary allows achieving an ultrahard state (with a hardness of about 50 GPa), which causes a relatively low friction coefficient. The obtained results on the formation of phase-structural states with the nanoscale thickness of layers of multi-period nitride coatings are explained from the position of minimization of surface energy and deformation energy.
А Computer Simulation of Radiation-Induced Structural Changes and Properties of Multiperiod ZrNₓ/MoNₓ System
(Sumy State University, 2017) Sobol, O. V.; Meylekhov, A. A.; Bochulia, T. V.; Stolbovoy, V. A.; Gorban, V. F.; Postelnyk, A. A.; Shevchenko, S. M.; Yanchev, A. V.
Influence of the period value Λ (at different negative potential Ub that supplied during deposition) on phase composition, structure, stress-strain state and hardness of multiperiod coatings ZrNₓ/MoNₓ is investigated by using complex methods of validation structural state at combined with microindentation. Formation in layers ZrNx and MoNx the phases with cubic lattice and preferred orientation of crystallites with axis [100] is established. Stress-strain state of compression with increasing Ub is amplified and reaches maximum value (– 6.7 GPa) at Λ = 20 nm and Ub – 110 V. Hardness of coating increases with decreasing Λ from 300 to 20 nm. Coatings that obtained with Λ = 20 nm and Ub – 110 V have the highest hardness 44 GPa. Relaxation of structural compressive stresses and decreasing hardness is happening at smaller Λ and larger Ub – 110 V (as a result of radiation-stimulated forming defect and mixing). Data of computer modeling of defectiveness at atomic level at bombardment of ions that accelerated in field Ub are used to explain the results.
Use of the method of micro-arc plasma oxidation to increase the antifriction properties of the titanium alloy surface
(Сумський державний університет, 2019) Subbotina, V. V.; Sobol, O. V.; Belozerov, V. V.; Makhatilova, A. I.; Shnayder, V. V.
The analysis of possibilities on phase-structural engineering of titanium-based alloys during micro-arc plasma oxidation (MAO) is carried out. The influence of phase-structural states on the tribotechnical properties of the modified surface of the titanium alloy VT3-1 is also considered. It has been established that in order to achieve high functional properties, it is necessary to use electrolytes of complex composition for MAO. The presence in the electrolyte of (NaPO₃)₆ leads to the formation of anatase with a low hardness (about 3 GPa). The formation of crystallites of rutile and aluminum titanate with the use of alkaline-aluminum electrolyte allows to increase hardness significantly (up to 7 GPa). The maximum increase in hardness (up to 12 GPa) is achieved in the coating obtained in alkaline-aluminate-silicate electrolyte. This is due to the formation of crystalline mullite. The friction coefficient of such a material decreases (f ‹ 0.01) and as a result, antifriction properties increase. The results of the work indicate the prospects for using the phase-structural engineering method for MAO-processing to optimize the formation of antifriction coatings on titanium alloys.