Alexander Pogrebnjak

Sumy State University | SSU · Department of Nanoelectronics

New conductive materials for tissue engineering are needed for the development of regenerative strategies for nervous, muscular, and heart tissues. Polycaprolactone (PCL) is used to obtain biocompatible and biodegradable nanofiber scaffolds by electrospinning. MXenes, a large class of biocompatible 2D nanomaterials, can make polymer scaffolds condu...

The present work deals with the comparison of selected properties of WN x /TiSiN multilayer and respective WN x and TiSiN monolithic coatings that were deposited at the same parameters. The effect of the multilayer architecture on the structure and mechanical properties of WN x /TiSiN multilayer was studied in detail. The multilayers and monolayers...

Bacterial cellulose (BC) is a biopolymer produced by different microorganisms, but in biotechnological practice, Komagataeibacter xylinus is used. The micro- and nanofibrillar structure of BC, which forms many different-sized pores, creates prerequisites for the introduction of other polymers into it, including those synthesized by other microorgan...

Innovative therapies are urgently needed to combat cancer. Thermal ablation of tumor cells is a promising minimally invasive treatment option. Infrared light can penetrate human tissues and reach superficial malignancies. MXenes are a class of 2D materials that consist of carbides/nitrides of transition metals. The transverse surface plasmons of MX...

In this study, the conductivity and permittivity of electrical pressboard—insulating liquid—water composites were investigated, and the electrical properties of the composites and water were analysed comparatively. Mineral oil and synthetic ester were used as insulating liquids. It was found that the presence of water caused an increase in the perm...

Nanocomposite multilayer coatings are of large interest to the engineering industry because of their functional properties. Titanium nitride-based multilayer structures are very effective as protective layers for mechanical instrumentation. In this paper, selected mechanical and tribological properties for cutting machinery of TiASiYN/CrN system we...

Due to the increased demands for drilling and cutting tools working at extreme machining conditions, protective coatings are extensively utilized to prolong the tool life and eliminate the need for lubricants. The present work reports on the effect of a second MeN (Me = Zr, Cr, Mo, Nb) layer in WN-based nanocomposite multilayers on microstructure,...

Monolayer tungsten nitride (WN) and multilayer WN/titanium nitride (TiN) and WN/titanium silicon nitride [(TiSi)N] coatings were produced by vacuum arc deposition on a Bulat-6 setup with continuous rotation of the substrate and samples. The results of the phase identification showed that the monolayer WN coating consisted of a cubic WN-β phase, whi...

The influence of silver ions on antibacterial properties and morphology of Hydroxyapatite-Ag (HА-Ag) and Hydroxyapatite-Alginate-Ag (HA-Alg-Ag) nanocomposites was studied. The microstructure and phase composition of the obtained nanocomposites were investigated by SEM, TEM, XRD, FTIR methods, and the formation of the crystalline phase of Ag 3 PO 4...

The paper examined Ti3C2Tx MXene (T—OH, Cl or F), which is prepared by etching a layered ternary carbide Ti3AlC2 (312 MAX-phase) precursor and deposited on a polycaprolactone (PCL) electrospun membrane (MXene-PCL nanocomposite). X-ray Diffraction analysis (XRD) and Scanning Electron Microscopy (SEM) indicates that the obtained material is pure Ti3C...

The ability to combine layers with high mechanical strength and additional physicochemical properties, such as biocompatibility, makes the use of multilayer coatings attractive for various applications. The transition from single layer to nanolaminate architecture can improve the mechanical performance of the coatings by increasing the number of in...

Nanoscale multilayer TiSiN/NbN coatings with a modulation period ranging from 75 to 50 nm were deposited onto steel using the cathodic arc physical vapor deposition technique. The microstructure of multilayer TiSiN/NbN coatings was nanocomposite consisting of nanocrystallite phases fcc-TiN and hcp- NbN-δ'. With the increase of the bias potential fr...

The paper describes mechanical, electrical and chemical properties of modified polycarbonate obtained by hot compression moulding of core-shell composites consisting of a polymer core covered with a shell containing single-walled carbon nanotubes (SWCNTs). Such an approach in material design based on an ultralow modification with nanomaterials allo...

A combination of coating deposition and consequent ion implantation could be beneficial in wear-resistant antifriction surface design and modification. In the present paper, the effects of low-energy 60 keV Si-ion implantation on multinanolayered CrN/ZrN grown on a stainless-steel substrate have been investigated. Complementary experimental (X-ray...

Nanocomposites based on hard compounds are currently on the stage of active research and development. Hence the analysis of a relation between nanostructure and functional properties are of great importance. The main purpose of the study was to assess the stoichiometry effect on the finite characteristics of TiZrC nanocomposite coatings. This paper...

Aerospace is an actively developing industry that continuously requires the implementation of modern technologies. The rapid growth in new vehicle production demands much support. Hence, the problem of resources with complicated supply and distribution is always of current interest. These critical raw materials (CRMs) are involved in almost all are...

Triply periodic minimal surfaces (TPMS) are known for their advanced mechanical properties and are wrinkle-free with a smooth local topology. These surfaces provide suitable conditions for cell attachment and proliferation. In this study, the in vitro osteoinductive and antibacterial properties of scaffolds with different minimal pore diameters and...

This paper introduces the theoretical and experimental investigation of multilayer (TiAlSiY)N/CrN coating deposited on a steel substrate using the cathodic-arc evaporation technique. The firstprinciples calculations show that the deposition of Ti1–xAlxN/CrN nanolayer with high Alx content (x = 0.75) has a severe stabilization effect that certainly...

The findings of the last years regarding the deep and machine learning algorithms provided the substantial impetus to the discovery of heretofore unknown data. The future of mechanical/electromechanical engineering lies in the design of smart materials and technologies. In this paper, the problem of material design in particular for applications in...

A series of nanolaminate (Al50Ti50)N/ZrN coatings with different modulation period (λ) and bias voltage were synthesized by vacuum arc deposition (VA-PVD). The composition, evolution of the microstructure, and mechanical properties were studied during the transition from the basic monolayer (Al50Ti50)N coating to the nanolaminate architecture with...

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In order to obtain the modified surface structure of the 20Cr2Ni4A steel plasma electrolytic hardening (PEH) method was used. The surface hardening process was conducted in the aqueous electrolyte solution of 20% sodium carbonate and 20% urea. The sample consists of a ferritic-pearlitic structure, i.e. the part retains its viscous core, and the sur...

The novel nanocomposite Ti-Si-La-N coatings were deposited using the cathodic arc evaporation process. The effect of different lanthanum contents (0 - 13 at.%) on the chemical composition, structural evolution, and mechanical properties of nanocomposites was studied. Analysis of structure showed that all Ti-Si-La-N series consisted of a crystalline...

Fabrication and development of HfB2-based nanostructured coatings was investigated. All films were deposited on stainless-steel substrates by RF magnetron sputtering from stochiometric HfB2 target in argon atmosphere. The aim of this work is to evaluate the effects of the bias potential on the microstructure, mechanical and tribological properties....

Open Access Link (by 10th of May 2020): https://authors.elsevier.com/a/1amRj3IWkc0GAX The main principles of formation of microstructure and properties of the nanostructured films consisting of periodically alternating multilayers of CrN/ZrN transition metal nitride films and Cr/Zr pure metals were investigated. First-principles calculations were c...

As result of plasma-electrolytic nitrocarburizing 30CrMnSiA carbon steel (ferrite-perlite grade), there was a change in the elemental and phase composition, as well as the surface layer microstructure (40 ÷ 45 microns thick from the surface). A formation of Me23(CN)6 carbonitrides, FeN nitrides, Fe3C - (Fe,Cr)3C carbides and an increase in dislocat...

A nanostructured composite material in the form of a hydrogel and beads based on hydroxyapatite (HA), sodium alginate (Alg) and ZnO microparticles was fabricated under the influence of microwave irradiation. An average crystallite size of the HA was 40 nm, while ZnO crystallites of the size 25 nm–11 µm were formed. The inorganic HA-ZnO phase of stu...

The scientific interest in the investigation of nitride composites as protecting materials in tool and machining industries intensively increases. The good oxidation resistance of CrN single-layer films and high melting point, good chemical and thermal resistance of ZrN compound are motive factors for designing of multilayer composites composed of...

One area of constant interest in many fields of industry is development of functional multilayer coatings that possess excellent performance characteristics. That is why in our brief review the results of studies of structure and properties of multilayer structures based on binary nitrides of transition or refractory metals obtained by various phys...

We report technical parameters of the deposition of multielement nitride protective coatings based on TiAlSiY by CA-PVD method and fractal analysis of their surfaces that are presented by the scanning electronic microscopy (SEM) images. Numerical analysis of the digital images was performed within two-dimensional multifractal detrended fluctuation...

Combined multilayered coatings based on alternative triple nitride and binary metallic layers were deposited using vacuum-arc evaporation of a cathode. (TiMo)N/TiMo, (CrMo)N/CrMo, (CrZr)N/CrZr, (TiCr)N/TiCr and (MoZr)N/MoZr multilayer coatings were fabricated under the same deposition conditions, while bias potential was −200 V. Total thickness of...

The presented work shows new results of a nanostructured composite material investigation. The fabricated and studied material was in the form of beads based on hydroxyapatite (HA), sodium alginate (Alg) and ZnO particles. The HA was produced under the influence of microwave radiation. The beads of HA–ZnO–Alg were fabricated by dropping slurry into...

Nowadays titanium-based alloys are widely used in various spheres, such as metallurgy, aerospace, aircraft industries, and medicine. Recent research has demonstrated that proper heat treatment and the addition of elements, stabilizing β phase, the properties of commercially pure (CP) Ti can be successfully modified application as an implant materia...

Multilayer AlN/BCN coating of nanometer scale have been prepared by magnetron sputtering of Al and B4C targets in an argon–nitrogen atmosphere during deposition on a Si substrate. These coating have an X-ray amorphous structure and the maximum Knoop hardness of 27 GPa (at the current density 100 mA). The first-principle molecular dynamics calculati...

Nanoscale multilayered TiN/SiC films are of great importance in many electronic and industrial fields. The careful control over the structure of the laminates, nanocrystalline or amorphous, is crucial for their further applicability and study. However, several limitations in their fabrication have revealed important gaps in the understanding of thi...

Main regularities of the formation of microstructure and properties of multilayer nanostructured CrN/MoN films with periodically changing architecture of layers were considered. Coatings were fabricated by vacuum-arc evaporation of the cathodes (Arc-PVD) in nitrogen atmosphere (pN was 0.4, 0.09 and 0.03 Pa). CrN and γ-Mo2N nitride phases with fcc l...

This research focuses on the characterization of multilayer ZrN/CrN coatings deposited by Arc-PVD technique on steel substrates. Structural and morphological properties of the deposited films are analyzed by optical microscopy and scanning electron microscopy. The quantification of crystalline phases in the coatings is obtained by X-ray diffraction...

A novel (TiZrNbTaHf)N/MoN nanocomposite coatings, which consist of the nitride of the high-entropy alloy and the binary nitride, were synthesized by vacuum-arc deposition at various substrate biases. The elemental composition, chemical bonding state, phase structure, microstructure and mechanical properties of the coatings were studied by high-reso...

ZrN/CrN multilayers have been produced by a cathodic arc technique (CA-PVD) using different depositions conditions. Microstructural and mechanical characterizations of the coatings were performed by X-ray diffraction (XRD), scanning electron microscopy with energy dispersive spectroscopy (SEM with EDS), transmission electron microscopy (TEM), and V...

Nanostructured multicomponent (TiAlSiY)N coatings were fabricated by the cathodic-arc physical vapor deposition (CA-PVD). In this study, a bias potential applied to the substrate was − 200 and − 500 V, and changes in structure and properties of coatings were investigated. Samples had a single-phase state with a face-centered cubic (FCC) lattice. Sm...

A comparative analysis of the structural features and tribological properties of multilayer coatings based on refractory metal compounds has been conducted in this review. Features of formation of the electronic structure of the synthesized coatings have been discussed, and the effect of methods and conditions of deposition on changes in the physic...

Multicomponent nanostructured coatings based on (TiZrNbAlYCr)N with a hardness as high as 47 GPa were obtained by cathodic arc deposition. The effect of partial nitrogen pressure PN (with constant bias potential Ub =–200 V applied to the substrate) on the phase-composition variation, the size of crystallites, and their relation to the microstructur...

The results of the investigations of the elemental composition and phase state of the Cu-Ti system after high-ion implantation and electron annealing by high-current electron beam (HCEB) are presented. It has been established that the use of high dose ((5…8)∙10¹⁷ ions/cm²) implantation and the subsequent effect of HCEB leads to a reduction in the c...

The multicomponent nitride coatings from TiZrNbAlYCr high entropy alloy (HEA) were fabricated using the vacuum-arc method. The effect of nitrogen pressure on the crystallite size, elemental and phase composition of (TiZrNbAlYCr)N coatings was investigated. A bias voltage applied to the substrate during the deposition process was −200 V. The partial...

Nanoscale multilayered TiN/ZrN films were deposited using sequential vacuum-arc deposition of Ti and Zr targets in a nitrogen atmosphere. Studies of film's properties were carried out using various modern methods of analysis, such as XRD, STEM, HRTEM, SIMS combined with results of nanoindentation and tribological tests. To interpret the mechanical...

Multilayer nanostructured coatings consisting of alternating MoN and CrN layers were obtained by vacuum cathode evaporation under various conditions of deposition. The transition from micron sizes of bilayers to the nanometer scale in the coatings under investigation leads to an increase in hardness from 15 to 35.5 GPa (with a layer thickness of ab...

The structure, elemental and phase compositions of the multilayered ZrN/CrN coatings obtained by the vacuum arc technique are investigated. The coatings are characterized by scanning electron microscopy with energy dispersive spectroscopy, X-ray diffraction and differential scanning calorimetry. A stronger preferred orientation along ZrN (200) plan...

New classes of high-entropy alloys, which consist of at least 5 main elements with atomic concentrations 5-35 at.%, are under great interest in modern material science. It is also very important to explore the limits of resistance of high-entropy alloy nitrides to implantation by high-energy atoms. Structure and properties of nanostructured multico...

We report on CrN/MoN multilayer coatings, their structure, elemental and phase composition, residual stresses, mechanical properties and their dependence on deposition conditions. The hardness and toughness were considered as main parameters for improvement of the protective properties of coatings. Multilayers with varying bilayer periods, ranging...

The main objective of this study consists in the characterization of ZrN/CrN ternary systems. The influence of the bilayer thickness (Λ) on microstructure and mechanical properties was evaluated for coatings synthesized by vacuum arc deposition. Multilayered two-phase nanostructures coatings ZrN/CrN were deposited by CA-PVD method. Microstructural...

In recent years, multilayer thin films have been the focus of several investigations. These multilayers may contain a certain amount of transition metals which enchance the properties, such as higher corrosion resistance or mechanical strength. The main objective of this work was the study of microstructure and performance analysis of ZrN/CrN multi...

Properties and performance of multicomponent thin coatings consisting of transition metal-based nitrides (M1M2M3N) are found to be superior to most commonly used ternary hard coatings. This paper reports on the deposition and characterization of (Ti-Zr-Nb)N coatings obtained by the vacuum arc deposition method. The stronger preferred orientation al...