Alexander E Sytschev

Merzhanov Institute of Structural Macrokinetics and Materials Science RAS · Materials science laboratory

The possibility of using the method of self-propagating hightemperature synthesis to obtain high-temperature cermet materials and non-removable layer compounds based on (NiAl)/oxide, where the oxides are SiO2, Al2O3 and 3Al2O3·2SiO2, is investigated. The thermodynamic analysis of gorenje reactions was carried out and the properties of the synthesiz...

High-temperature interaction of 30 wt % Cu–70 wt % Ag eutectic alloy with carbon fibers was studied. It was shown that Cu–Ag drops coated with carbon film are formed on the surface of carbon fibers. Carbon atoms dissolved in the molten Cu–Ag phase precipitated out on the drop surface at a lower temperature, thus resulting in growing few-layer graph...

The influence of Mn addition on combustion synthesis, morphology, phase composition, and magnetic properties of the Ni–Al–Mn alloys was investigated. Ni–Al–xMn alloys with various Mn concentration (x = 0–1.5) were prepared by combined use of mechanical activation and self-propagating high-temperature synthesis (SHS). It was found that the phase com...

Abstract—Ti–24Al–33Mn alloy containing cubic TiMn0.32Al2.68, hexagonal TiMn0.755Al1.246, and Mn3Al2 was prepared by combustion synthesis (SHS method). The synthesized samples were shown to have sufficiently high porosity with individual pore sizes up to 300–400 μm.

Growth of graphene film on the Cu-Ag eutectic alloy surface under conditions of high-temperature interaction with carbon wires.

This paper investigates the features of the high-temperature interaction of carbon fibers with a nickel melt under the action of a short electric pulse and the formation of a multilayer graphite coating on the nickel surface. The saturation of a nickel droplet with carbon is achieved by diffusion on contact with carbon fibers. A multilayer graphite...

The electrical conductivity of powder media depends on the composition, impurities, oxide films, morphology and the nature of the contact surface. We present the results of studying the electrical resistance of powder materials and their compounds under continuous loading by the four-contact method. The electrical resistance is determined using a s...

In this communication, we report on the deposition of copper coatings onto the surface of graphite fibers under the action of pulsed direct current. The EDS analysis of spherivcal Cu particles showed the presence of 80 at % Cu and 20 at % С, which corresponds to interstitial solution Cu(C). The Cu coating was found to consist of either spherical pa...

Self-propagating high-temperature synthesis (SHS) is an attractive technique to synthesize a variety of advanced materials [1]. It is based on the concept that once initiated locally by means of a thermal source of short-term-service, highly exothermic reactions become self-sustaining and yield the final product progressively without requiring addi...

We performed high-temperature treatment of the Ni–C, Al–C, and Ni–Al–C powder mixtures (5 wt % C (soot)) up to the melting point of the respective metals and found that the melt particles coagulate with formation of Ni, Al, and NiAl (intermetallic) spherical particles, respectively. The Ni particles have almost perfect spherical shape and a multila...

Ultra-high-temperature Ta4HfC5 ceramics with a submicron structure has been manufactured from a 4Ta + Hf + 5С powder mixture by electro-thermal explosion under pressure. The effect of the duration of mechanical activation of starting 4Ta + Hf powder mixtures on the structure of the resulting precursor has been studied. It has been demonstrated that...

Lightweight Ti–Al–Si intermetallic alloys with the compositions (wt %) 37Ti–50Al–13Si, 74.1Ti–6.3Al–19.6Si, and 41.53Ti–16.71Al–41.76Si have been prepared for the first time by self-propagating high-temperature synthesis (SHS). Using a 74.1 wt % Ti + 6.3 wt % Al + 19.6 wt % Si mixture, we have obtained a single-phase material with the composition T...

The effect of carbon (3 wt %) on the electrical resistivity of alloys based on aluminum nickelides Ni–Al and Ni–Al–C synthesized by electrothermal explosion in the temperature range of 300–1300 K in a vacuum of 2 × 10–3 Pa has been studied. At an electrothermal explosion in a powder reaction medium, a Ni–Al-based melt is formed in which carbon diss...

We have studied the structuring of combustion products in the Ti–Al system upon interaction with carbon fibers during self-propagating high-temperature synthesis. The combustion products have been characterized by X-ray diffraction and scanning electron microscopy in combination with X-ray microanalysis using an energy dispersive detector. The resu...

The high-temperature treatment of powder mixtures of Ni-C, Al-C and Ni-Al-C (5% wt C (soot)) has been carried out up to the melting temperature of the metals. It was found that melt particles coagulate with the formation of spherical particles of Ni, Al, and the intermetallic compound NiAl, respectively. Ni particles are characterized by the almost...

A composite material based on the Ni–Al–C system is synthesized by the method of an electrothermal explosion at a pressure of 96 MPa. During the electrothermal explosion in a reactive powder medium (Ni + Al + C), a Ni- and Al-based melt is formed, in which carbon dissolves. In the process of crystallization of the final product, carbon, due to its...

In this study we aim at examining the effect of in-situ and ex-situ interfacial ceramic layers at the Al-CNT interface on the thermal expansion coefficient of aluminum matrix composites at different temperatures. For this, two types of bulk composite materials were obtained by a combination of high-energy ball milling and hot pressing methods. Thes...

A lightweight intermetallic alloy containing the ternary phase Al18Ti2Mg3 has been prepared for the first time in the Ti–Al–Mg system by self-propagating high-temperature synthesis. In the binary system Ti–Al, synthesis has been carried out in the thermal explosion regime, whereas in the ternary system Ti–Al–Mg layer-by-layer combustion synthesis h...

Growth of graphene and graphite films on the nickel surface under conditions of high-temperature processing. Examples of deformation and bending of layers under loading.

Combustion of mechanically activated mixtures in 2Co–Ti–Al and Co–2Ti–Al is in�vestigated, and alloys based on them are obtained by self-propagating high-temperature synthesis (SHS). Microstructural, X-ray, and differential-thermal studies are performed. A Heusler phase Co2TiAl-based alloy is obtained for the first time by means of mechanical activ...

A material based on a (VCr)2AlC solid solution has been obtained for the first time by self-propagating high-temperature synthesis from a powder reaction mixture of vanadium(V) and chromium(III) oxides with aluminum and carbon (graphite). The synthesized material has been studied by X-ray diffraction and microstructural analyses. It has been shown...

An intermetallic alloy based on the Heusler phase—Cu2TiAl—has been obtained by self-propagating high-temperature synthesis (SHS) in the Cu–Ti–Al system for the first time. The modes of frontal combustion of the green mixtures and the processes of phase formation during synthesis have been studied. The resulting products have been studied by X-ray a...

In this paper, we studied the effect of carbon (3 wt. %) on the electrical resistivity of materials based on Ni − Al and Ni – Al − C synthesized by the electrothermal explosion in the temperature range 300 – 1300 K in a vacuum of 2·10–3 Pa. During an electrothermal explosion, a Ni – Al-based melt is formed in a powder reactive medium, in which carb...

The catalytic growth of multilayered graphite/graphene on a transition metal substrate (Ni, Co, Cu) and intermetallics (Ni-Al, Fe-Al) is presented. A remarkable example is that (in case of intermetallics) graphene was obtained by self-propagating high-temperature synthesis (SHS).

For the first time, an intermetallic alloy based on the Heusler phase – Cu2TiAl – was obtained by self-propagating high-temperature synthesis (SHS) in the Cu–Ti–Al reaction mixture. The frontal combustion modes of green mixture compositions and phase formation processes during synthesis were studied. The products obtained were studied by X-ray diff...

This study describes the effect of preliminary mechanical activation and SiO2 quartz content on combustion rate, maximum combustion temperature, sample elongation during combustion, compressibility of mixtures, composite particle size, phase composition, and the structural features of combustion products in a Ni–Al–SiO2 system. In Ni–Al–SiO2 initia...

Nowadays the investigation of new lightweight alloys based on titanium aluminides is of great interest. Various low-density dispersion-strengthening additives are used for their synthesis. In this work Ti-Al-Mg lightweight alloy was synthesized using the methods of layer-by-layer combustion and thermal explosion. Relative sample elongation, combust...

The composition and crystal structure of compounds produced by self-propagating high-temperature synthesis (SHS) from the 5Ta-2Ni-3Al (at %) powder mixture followed by vacuum remelting at 3000°C are studied. The SHS product contains the following phases: TaNiAl (Laves τ 1 phase), NiAl, Ni 2 Al 3 , and Ta. Its microstructure includes Ta 85 Ni 7 Al 8...

The TiN/TiAl3/Ti2AlN composite material is fabricated in the filtration combustion mode in nitrogen of porous samples made of the TiAl intermetallic powder consolidated under thermal vacuum treatment. The weight content of each phase, which was 42% TiN, 35% TiAl3, 20% Ti2AlN, and 3% TiAl, is calculated from the X-ray phase analysis data of combusti...

A cermet material based on the system Ni–Al–SiO2 with different SiO2 weight content (0 – 50%) in the mixture was obtained by means of self-propagating high-temperature synthesis (SHS) with preliminary mechanoactivation (MA). It is shown that preliminary mechanoactivation of the powder mixture strongly affects the morphology of the final product. De...

MAX-phase microstructure in the Ti-Zr-Al-C system.

MXene microstructure in the Ti-Si-C system after chemical etching and removal of Si. Self-Propagating High-Temperature Synthesis in the Ti–Si–C System: Features of Product Patterning. S. G. Vadchenko, A. E. Sytschev, D. Yu. Kovalev, A. S. Shchukin, and S. V. Konovalikhin. Nanotechnologies in Russia, 2015, Vol. 10, Nos. 1–2, pp. 67–74.

MAX-phase microstructure in the Ti-Si-C system. Self-Propagating High-Temperature Synthesis in the Ti–Si–C System: Features of Product Patterning. S. G. Vadchenko, A. E. Sytschev, D. Yu. Kovalev, A. S. Shchukin, and S. V. Konovalikhin

The peculiarities of structure and phase formation in the 5 Ta–2 Ni–3 Al intermetallic system are studied in the paper. The TaNiAl, NiAl, Ni2Al3, and Ta phases are found in the alloy produced by self-propagating high-temperature synthesis (SHS). A transition layer with the composition of Ta51Ni20Al29 about 1–2 μm thick is formed on the interface be...

Composite materials based on a 5xxx series aluminum alloy strengthened with 0.1 wt % of multiwalled carbon nanotubes (MWCNTs) or 0.1 wt % WC1 – x/MWCNTs were synthesized by high-energy ball milling and subsequent gas extrusion. The structural phase composition and physicomechanical properties of bulk composites are characterized. A comparison with...

Combustion synthesis experiments in the Ni–Al–C system showed the possibility of obtaining material using carbon components (soot, graphite, carbon nanotubes) in the combustion regime. The carbon predominantly located along the boundaries of intermetallic NiAl grains forms a continuous multilayered film on their surface with a thickness of about 66...

In this communication, we report on the preparation of Ni–Al–C composites by spark plasma sintering (SPS) and their characterization.

Combustion and the formation of structures and phases in a 2Co-Ti-Al system during self-propagating high-temperature synthesis in a thermal explosion are under study. It is determined that a single-phase product (a Co 2 TiAl Geissler compound) can be obtained in this system. Morphology, microstructure, and physical-magnetic properties of combustion...

In this work, the influence of mechanical treatment (mechanical milling) of the TiN titanium nitride powder produced by self-propagating high-temperature synthesis on the magnetic properties of the milled powders is investigated. The effect of d0-magnetization was observed. The TiN powders were characterized by scanning electron microscopy, X-ray d...

Mechanically synthesized hybrid powders of the AMg2/graphite + Al2O3 system and coatings deposited by cold gas dynamic spraying from these powders are studied. The effect of Al2O3 concentration in the powder on surface morphology, structure and microhardness of the coatings formed is determined.

In this paper, we present the results of producing bulk composite materials based on aluminum alloy AlMg2, hardened 0.1-5 wt.% MWCNT and decorated with TiC nanoparticles by powder metallurgy method. Powder and bulk composites were characterized by electron microscopy, X-ray diffraction, kinetic indentation and compression tests. The influence of hy...

Effect of carbon content in a Ni–Al–C system and preliminary mechanical activation on a burning rate, sample elongation, and mixture yield after mechanical activation, as well as on the structural features of combustion products is under study. Combustion in pressed samples from a mechanically preactivated Ni + Al mixture at room temperature could...

The TiN/TiAl3/Ti2AlN composite material was obtained by filtration combustion of the porous TiAl intermetallic samples in gaseous nitrogen. X-ray phase analysis of combustion products provided data to calculate the weight content of each phase as follows: 42 wt.% TiN, 35 wt.% TiAl3, 20 wt.% Ti2AlN and 3 wt.% TiAl. The synthesized composite material...

The stability of combustion wave passing through the interface between two different SHS systems is also of current importance in the task objective of reliable SHS joining of dissimilar materials. Transition of combustion wave from one burning material to another is normally accompanied by transient phenomena such as pulsations of combustion tempe...

Compounds based on Co–Ti–Al system are produced in various ways: arc melting, shock wave synthesis, spark plasma sintering. In the practice of creation of intermetallic materials by the method of self-propagating high-temperature synthesis (SHS), the question of obtaining intermetallic compounds of both binary and ternary systems is widely investig...

The peculiarities of the formation of the structure of intermetallic Ni–Al alloys modified by carbon components in the mode of self-propagating high-temperature synthesis (SHS) and spark plasma sintering (SPS), and the influence on the structure of preliminary MA are investigated in this study

Abstract. The hybrid powders AlMg6/C60 + 10-70 wt.% Al2O3 and AlMg6/C60 + 10-70 wt.% AlN were obtained by the method of mechanical synthesis in a planetary ball mill. These powders were used to create coatings using cold gas-dynamic spraying. The influence of the type and concentration of ceramic reinforcement on the growth efficiency and microhard...

Abstract—We have studied in detail the structuring of combustion products in the Ti–Al–C system at low carbon concentrations (96 wt % (Ti + Al) + 4 wt % graphite) prepared by self-propagating high-temperature synthesis and compared the results to those for carbon-free samples prepared by the same method. A thin (~500 nm) TiC carbide layer has been...

This work has demonstrated the possibility of joining (“welding”) a coating of intermetallic compound NiAl to an Mo substrate using the self-propagating high-temperature synthesis (SHS) method, without melting the Mo substrate. It has been revealed that an intermediate layer is formed between the Mo substrate and the welded NiAl coating. The main c...

We investigated the peculiarities of the combustion synthesis (or self-propagating high-temperature synthesis − SHS) as well as the structure and phase formation in the Ni–Al–C system. Different carbon components (soot, graphite, carbon nanotubes) were used for synthesis of Ni–Al based intermetallic materials. The synthesized materials were charact...

The paper presents results of experimental studies of a slow (during 50÷100 μs) electric explosion of thin titanium wires in argon and air media. In that explosion wire destruction and its fragmentation are complex processes associated with thermo-mechanical stresses and electromagnetic forces. The explosion was characterized by oscillography and p...

Cast composite material based on Cr2AlC MAX phase has been prepared by metallothermic selfpropagating high-temperature synthesis (SHS) from a mixture of powders of chromium oxide, aluminum, and carbon. The experiments have been performed using an SHS reactor with a volume V = 3 L under an excess inert-gas (Ar) pressure (P = 5 MPa). The prepared mat...

This paper describes the possibility of welding (joining) the Mo substrate with NiAl intermetallic compound by the method of self-propagating high-temperature synthesis (SHS) without melting the Mo substrate. It was found that an intermediate layer is formed between the Mo substrate and the intermetallic welding, the main component of which is a ce...

The paper presents the results of experimental studies of the powder production by an electric explosion of titanium fibers in argon media. The main features of energy input in the fibers and its phase transformation were established. It was found that spherical titanium particles (with a diameter of 80-170 μm) were produced at energy consumptions...

The structure, phase composition, and electrical conductivity of TiB2–AlN–BN-based ceramics fabricated by self-propagating high-temperature synthesis (SHS) are investigated. The temperature dependence of the specific electrical conductivity was measured in range T = 300–1300 K in vacuum of 2 × 10–3 Pa according to the standard four-probe dc-current...

New-generation superalloys based on Ni intermetallics possess high thermomechanical stability at high temperatures and are widely used in modern industry. The fabrication of such materials by self-propagating high-temperature synthesis (SHS) is advantageous over traditional metallurgical technologies due to the use of the chemical-reaction energy....

The structure, composition, surface area and catalytic activity of Solution Combustion Synthesis (SCS) catalysts are all influenced by the conditions of preparation and in particular, the glycine concentration in the initial SCS solution. NMR was used to monitor the formation of glycine-nickel nitrate complexes in solution before SCS initiates, IR...

The experimental results of study the W– 10NiAl composite produced by means an electro-thermal explosion method (ETE) under pressure are presented. The basis of the ETE method is Joule heating of the sample pressed from the tungsten, nickel and aluminum powders, and consolidation of the hot synthesized product under pressure. For the first time, th...

Abstract—The structure, phase composition, and electrical conductivity of TiB2–AlN–BN-based ceramics fabricated by self-propagating high-temperature synthesis (SHS) are investigated. The temperature dependence of the specific electrical conductivity was measured in range T = 300–1300 K in vacuum of 2 × 10–3 Pa according to the standard four-probe d...

An effect of a NiO additive on the combustion and structure formation in a Ni–Al–W system in self-propagating high-temperature synthesis (SHS) is under study. The stages of the combustion of compositions containing a NiO high-energy additive are shown. The interaction of W particles with Ni–Al melts during SHS results in the formation of globular d...

Abstract—The high-temperature conductivity of ceramics based on Al–AlN–TiB2 obtained by self-propagating high-temperature synthesis has been studied. The dependences of DC resistivity were measured in vacuum (1 Pa) by a four-point technique in a temperature range of 293–1273 K. The evolution of the phase composition of the material upon heating was...

An experimental and computational study of the formation of pure iron nanoparticles, carbon nanoparticles (soot), and binary carbon-coated iron nanoparticles during the pyrolysis of iron pentacarbonyl–argon, ethylene–argon, and iron pentacarbonyl–ethylene–argon mixtures, respectively, behind reflected shock waves is carried out. The shape and size...

NiAl intermetallic is obtained during exothermic reaction of mechanically activated Ni and Al powders, taking place by thermal explosion (TE) mode of self-propagating high-temperature synthesis (SHS). When a layer of Ni–Al blend is placed in contact with Ta substrate, the heat this exothermic reaction results in reaction multilayer with composition...

A method of mechanical synthesis in a planetary ball mill produced composite powders based on a nanocrystalline Al-Mg matrix reinforced with micro additives of Al / MWCNTs. The granulometric composition of the obtained composite powders was studied. It has been established that the concentration of Al / MWCNTs does not significantly affect the aver...