Volume 95, №7
ACCOUNTING FOR FUNCTIONS OF DISTRIBUTION OF MECHANICAL PROPERTIES OF METALS IN DYNAMIC PROCESSES OF DEFORMATION AND DESTRUCTION OF BARRIERS
Based on a discrete model of a heterogeneous continuous medium, the possibility of constructing models of complex
heterogeneous and gradient media has been shown. A generalization of the said model into construction metals
having a spread of mechanical properties within a certain value range has been made. The performed calculations
modeling the process of perforation of an aluminum barrier that has a normal yield stress distribution have shown a
realistic conformity of the computational results to the experimental data
Author:
V. M. Fomin, A. E. Kraus, E. I. Kraus, I. I. Shabalin, A. E. Buzyurkin
Keywords:
equation of state, destruction, numerical modeling, mechanical properties, heterogeneous materials, shock waves
Page:
1625
A COMPARATIVE ANALYSIS OF TWO APPROACHES TO NONLOCAL DUCTILE DAMAGE MODELING
A new nonlocal version of Gurson–Tvergaard–Needleman model is presented, which includes a new scheme of
delocalization of constitutive relations. The delocalization scheme has the eff ect of trapping the damage, which
makes it possible to increase the accuracy of modeling the processes of destruction and to avoid excessive diff usion
of material damage. As an alternative approach, a nonlocal thermodynamically consistent model of damage
accumulation developed earlier is considered. For both models, effi cient schemes of integrating constitutive relations
are presented. Using the problem of the destruction of a strip with a hole as an example, the results obtained
by both models are compared. Despite the fact that the models under consideration are based on fundamentally
diff erent hypotheses, the predicted integral characteristics and distributions of plastic deformations coincide with
high accuracy. The coincidence of the predictions by two diff erent models greatly complicates the choice of model
hypotheses based on integral characteristics. It is established, however, that for the two models there is a signifi cant
discrepancy in the predictions of the local evolution of the porosity of the material. Thus, in the presence of reliable
experimental data on local material damage, this eff ect can be used as the basis for new protocols for selecting and
calibrating models.
Author:
V. S. Klyuchantsev, A. V. Shutov
Keywords:
nonlocal damage mechanics, large deformations, Gurson–Tvergaard–Needleman model, fi nite element method
Page:
1634
DETERMINING THE MODULUS OF DILATATION OF VARIOUS MATERIALS USING THE MOLECULAR-DYNAMICS METHOD
Within the framework of the molecular-dynamics method, the authors have investigated the dependence of the
modulus of dilatation of metals on the dimension of a nanostructure. For this purpose, use was made of the original
procedure of numerical experiment, developed by the authors. It has been shown that beginning with a certain
critical dimension, the modulus of dilatation grows as the nanostructure's dimension decreases.
Author:
A. V. Utkin, V. N. Fomin
Keywords:
molecular-dynamics method, modulus of dilatation, nanostructure, nanocluster
Page:
1647
CRITICAL DYNAMICS OF DAMAGE TO COMPOSITES AND TWO-PARAMETER FRACTURE CRITERIA
The dualism of the regularities of transition from the dispersion accumulation of damages to macroscopic failure,
which is presented in two-parameter criteria of fracture, is tied to two types of singular solutions in solid bodies
with defects: self-similar intermediate-asymptotic distribution of stresses in the vicinity of the crack tip and selfsimilar kinetics of localization of the damage. In addition to the value of the coeffi cient of stress intensity, two
extra parameters (cohesive strength and cohesion length) are determined by kinetic conditions for the formation of
fracture zones on the characteristic spatial scale when the critical values are attained by the stresses in the zones
of local damage. These parameters are associated with the nonlinear self-similar kinetics of damage localization,
and the existence of two self-similar solutions determines diff erent stages of fracture, including the initiation and
propagation of cracks and the fracture of specimens in the presence of concentrators. The stages of development
of fracture in the presence of two types of self-similar solutions is investigated experimentally from the data on the
kinetics of crack extension in PMMA and DIC data during the deformation of a composite specimen with a circular
concentrator, and also demonstrates the analogous dynamics of stages of fracture, which confi rms the possibility of
using two-parameter criteria to describe the stages of fracture
Author:
O. B. Naimark, S. V. Uvarov, M. V. Bannikov, Yu. V. Bayandin, A. S. Nikityuk
Keywords:
critical dynamics, damage, two-parameter criteria, DIC, phase portraits
Page:
1652
EXPERIMENTAL INVESTIGATION OF THE HIGH-RATE INTERACTION OF A CLOUD OF MICROPARTICLES WITH A METAL WITH THE USE OF A RAIL ACCELERATOR
A new electrodynamic method of deposition of microparticles of a solid material (tungsten carbide) on the surface
of a steel target is considered. A tungsten carbide powder enclosed in a plastic container was accelerated with
the use of a rail accelerator, and a "plasma piston" was used as a current-carrying pusher. A signifi cant infl uence
of the attendant gasdynamic processes on the fl ow of the indicated particles, moving with a velocity of about
1400 m/s, is demonstrated. It is shown with the use of the electron-microscopy and nanoindentation methods that
the microparticles deposited on the surface of a steel target substantially infl uence its structure and the mechanical
properties of the near-surface layer: the microhardness of the material of the target increases by 1.4 times. It was
established that a thin layer of microparticles is formed on the surface of a metal treated with them and that these
particles are embedded in its structure
Author:
V. M. Fomin, T. A. Brusentseva, A. A. Filippov, M. A. Yadrenkin, P. E. Tyustin
Keywords:
electrodynamic rail accelerator, tungsten carbide, steel target, coating, nanoindentation, electron microscopy
Page:
1659
STUDY OF THE DEPENDENCE OF THE MELTING TEMPERATURE OF ALUMINUM NANOPARTICLES ON THE PARTICLE SIZE
Numerical simulation of the process of melting of aluminum nanoparticles is carried out with the use of the
methods of molecular dynamics. It is established that the melting of aluminum particles depends on the potential
of their interaction and on the type of the particle symmetry. Dependence of the melting temperature of aluminum
nanoparticles on the size of the latter is investigated
Author:
I. A. Bedarev, S. A. Lavruk
Keywords:
molecular dynamics method, melting, nanoparticles, aluminum
Page:
1672
WEAR-RESISTANT DETONATION COATINGS BASED ON CHROMIUM CARBIDE FOR GAS TURBINES
A systematic study of detonation deposition of wear-resistant coatings made of composite powders based on chromium carbide used to harden parts operating at temperatures up to 870oC is carried out. An integrated analysis of the characteristics of coatings produced from powders of Russian and foreign manufacturers was carried out. A composite in the form of mechanical mixture and powders obtained by cladding and the Spray–Dry method are considered. Using a numerical code, the acceleration and heating of particles of the sprayed powder are calculated and the optimal spraying modes are determined. The hardness, porosity, wear resistance, and bond strength of the resulting coatings were considered. A comparative characterization of residual stresses has been carried out. The infl uence of the spraying distance in the range from 50 to 400 mm and of the inclination angle of the treated surface up to 60o
has been studied. It is shown that in the case of dual-fuel mixture spraying, the density and wear resistance of coating increase and residual tensile stresses are completely eliminated. The adhesion of the resulting coatings exceeds 150 MPa, and the abrasive resistance of the best coating is characterized by a specifi c wear of about 3 mm3
/1000 rpm according
to the ASTM G65 standard, which is 5 times higher than the resistance of the alloys used for the manufacture of gas
turbine parts.
Author:
I. S. Batraev, K. V. Ivanyuk, D. K. Rybin, V. Yu. Ul′yanitskii, A. A. Shtertser
Keywords:
detonation spraying, wear-resistant coatings, chromium carbide, microstructure, adhesion, residual stresses.
Page:
1677
RAMAN SPECTROSCOPY OF IMPACT POPIGAI ASTROBLEME DIAMONDS HEAT TREATED AT 5.5 GPa
Experimental data are presented on the Raman spectra and surface graphitization of impact diamonds of Popigai astrobleme that were heat-treated at 5.5 GPa in a wide temperature range (1500–2250o
C). It has been established that light-colored (without inclusions of graphite) impact diamonds are extremely resistant to thermobaric action. Bulk graphitization of diamonds is not recorded up to 2250o
C at 5.5 GPa. Dark-colored diamonds (with inclusions of graphite) turned out to be less resistant to high temperatures. Their complete graphitization was achieved at temperatures above 2000o
C. Owing to the extreme resistance of impact diamonds of Popigai astrobleme to
thermobaric eff ect, they can be widely used in the manufacture and use of diamond tools.
Author:
A. I. Chepurov, S. V. Goryainov, E. I. Zhimulev, V. M. Sonin, A. A. Chepurov, Z. A. Karpovich, V. P. Afanas'ev, N. P. Pokhilenko
Keywords:
diamond, graphitization, high temperatures and pressures, Raman spectroscopy
Page:
1697
COMPARATIVE CHARACTERISTICS OF IMPACT DIAMONDS OF THE POPIGAI ASTROBLEME AND SYNTHETIC DIAMONDS PRODUCED BY EXPLOSION
The paper presents the characteristics of impact diamonds from the Popigai meteorite crater, formed by martensite
transformation of graphite-bearing gneisses due to meteorite impacts. These diamonds have a nanopolycrystalline
structure and consist of two phases, i.e., cubic (diamond) and hexagonal (lonsdaleite). They are distinguished by
phenomenal abrasion resistance, on average twice as high as the abrasion resistance of single-crystalline diamonds.
The work considers the possibility of producing similar diamonds by explosion. It is noted that diamonds, which are
most similar in structure, are produced through exploding a composition of graphite and hexogen; lonsdaleite is
present in the material obtained in this way. However, in any case, diamonds produced by explosion are very small
in size, incomparable with natural ones.
Author:
V. P. Afanasiev, É. R Pruuel, A. E. Kurepin, S. A. Gromilov, P. A. Vityaz
Keywords:
Popigai astrobleme, diamond, lonsdaleite, yakutite, explosives, recovery ampoule
Page:
1697
INVESTIGATING THE COMBUSTION OF ENERGETIC MATERIALS WITH A BORON ADDITIVE BY THE METHOD OF SMALL-ANGLE X-RAY SCATTERING
The authors have presented results of investigation into the process of combustion of solid specimens consisting of
ammonium perchlorate and a binder with boron and aluminum-dodecaboride additives by the method of small-angle
x-ray scattering with a high time resolution using high-speed optical photography. An analysis has been made of
the particles preserved after the combustion. It has been shown that the procedure of small-angle x-ray scattering
permits recording particles of the B and AlB12 additive directly in the combustion wave of the compound.
Author:
É. R. Pruuél, I. A. Rubtsov, A. A. Cheremisin, O. G. Glotov, V. A. Poryazov, G. S. Surodin, A. O. Kashkarov, A. A. Studennikov
Keywords:
small-angle x-ray scattering, synchrotron radiation, combustion of boron
Page:
1703
STUDY OF COMBUSTION PROCESSES OF ENERGETIC MATERIALS BY AEROSOL AND OPTICAL METHODS
The dispersed composition and mass concentration of the condensed phase formed during the combustion of highenergy materials, model fuels containing aluminum and boron, were studied at atmospheric pressure and at elevated
pressures in a closed high-pressure vessel. Particle size distribution, as well as mass concentration of the suspended
dispersed phase in a wide range of particle sizes and pressures were determined.
Author:
A. A. Cheremisin, V. V. Karasev, A. M. Baklanov, S. V. Valiulin, Yu. M. Milekhin, A.N. Chernyi
Keywords:
combustion, solid propellant, aluminum, boron, condensed combustion products, fi nely dispersed oxide
Page:
1708
THE EFFECTS OF FLUORINE-CONTAINING ADDITIVES IN COMPOSITE PROPELLANTS WITH BORON AND ALUMINUM DODECABORIDE ON THE CHARACTERISTICS OF THEIR COMBUSTION
The screening method has been used to investigate the eff ects of magnesium fl uoride, polytetrafl uoroethylene, and
ammonium hexafl uorotitanate additives in a composite propellant on the basis of boron or aluminum dodecaboride
as a fuel (37%), ammonium perchlorate as an oxidizer and an active binder on the parameters of propellant
combustion. At pressures of 1.2 and 2.4 MPa, propellant combustion rates were measured, samples of condensed
combustion products were taken, and burning residue in the form of a carcass was investigated. Using the cerimetric
method of chemical analysis of the selected combustion products, incompleteness of propellant combustion was
indentifi ed and the effi ciency of its energy release was evaluated. It is shown that the addition of small quantities
(1%) of the said substances to the propellant makes it possible to control the velocity of its combustion and, in some
cases, to raise the effi ciency of energy release.
Author:
O. G. Glotov, V. V. Zamashchikov, G. S. Surodin, N. S. Belousova
Keywords:
ramjet engine, composite propellant (propellant mixture), boron, aluminum dodecaboride, magnesium fl uoride, polytetrafl uoroethylene, ammonium hexafl uorotitanate, combustion velocity, condensed combustion products, selection method, completeness of combustion, cerimetric analysis, energy extraction effi ciency
Page:
1716
SIMULATION OF THE DYNAMICS OF IGNITION AND COMBUSTION OF BORON PARTICLES IN SHOOK WAVES
A numerical algorithm has been developed and simulation of the ignition and combustion of a boron microparticle of diameter from 7.5 to 20 μm in oxygen behind a shock wave refl ected from the wall has been simulated. The mathematical simulation is based on a modifi ed PSU model of boron combustion. The model takes into account boron boiling. The dynamics of ignition and combustion of a particle is obtained that includes heating of the oxide layer of B2O3 on the
particle surface, the melting of this layer, evaporation and heating of a pure boron particle, its melting, boiling, and
the corresponding chemical reactions. The computational algorithm was verifi ed with the use of experimental data.
The argument is obtained on the ignition delay time in the ambient gas temperature range from 2200 to 3000 K.
Author:
I. A. Bedarev, A. A. Syrovaten′
Keywords:
ignition of particles, combustion of particles, boron, shock waves, numerical simulation.
Page:
1724
KINETIC LAWS GOVERNING THERMAL DECOMPOSITION OF PERCHLORATE NICKEL ORGANOMETALLIC COMPLEXES UNDER CHANGES OF THE LIGAND NATURE
As a result of the interaction of nickel perchlorate with ethylenediamine, imidazole, and semicarbazide, complex compounds Ni(En)3(ClO4)2, Ni(Im)6(ClO4)2, and Ni(SC)3(ClO4)2 have been obtained, the structure and composition of which were confi rmed by elemental analysis and by the method of the infrared spectroscopy of frustrated total internal refl ection. The kinetics of the thermal decomposition of synthesized compounds in an inert medium was studied within the framework of the traditional method of thermal analysis in a helium atmosphere at a rate of the heating of samples of 5o
C/min and under conditions of their high-speed heating (>100o
C/min) with simultaneous
determination of the composition of gaseous products of thermal decomposition of the material.
Author:
A. G. Shmakov, A. A. Paletskii, O. V. Komova, S. A. Mukha, K. A. Dmitruk, O. V. Netskina
Keywords:
organometallic complexes, ethylenediamine, imidazole, semicarbazide, perchlorate nickel, thermal decomposition kinetics
Page:
1732
PROSPECTS OF USING SYNCHROTRON RADIATION FOR DIAGNOSTICS OF THE STRUCTURAL-PHASE COMPOSITION OF COMPOSITE MATERIALS
Diagnostics of the structure of materials is necessary for determining subsequent technological operations in the
production of fi nished products. In the present paper, we propose to use synchrotron radiation for investigating the
phase composition of metal-ceramic coatings with a titanium alloy as a matrix and powdered titanium boride as
reinforcing elements. A comparison of the results obtained from the diff raction of x-ray tube radiation (Cu) and
synchrotron radiation has shown that when it is necessary to determine the phases containing light elements (in the
present case B), diff raction of synchrotron radiation makes it possible to unambiguously reveal TiB in the resulting
coating, whereas diff raction of x-ray tube radiation could not allow unambiguous interpretation of results. Thus, the
advantage of the synchrotron radiation in diff raction studies has been shown.
Author:
V. M. Fomin, A. I. Ancharov, N. V. Bulina, I. E. Vitoshkin, A. A. Golyshev, A. G. Malikov, A. M. Orishich
Keywords:
additive technologies, x-ray phase analysis, synchrotron radiation, Ti64, TiB.
Page:
1746
X-RAY STUDY OF THE INTERACTION OF SHOCK WAVES IN STRUCTURAL MATERIALS USING SYNCHROTRON-RADIATION SOURCES
Conducts of high-speed x-ray experiments on recording the interaction of shock waves in structural materials with
synchrotron radiation are discussed using polycarbonate and magnesium as an example. The regimes of refl ection
of a shock wave from an obstacle, of collision of counter-propagating shock waves in a cylinder, and of descent of
a shock wave from the lateral surface of the cylinder toward its center have been implemented. Diff erences in the
mechanics of mass fl uxes arising in polycarbonate and magnesium on exposure to shock waves have been shown
Author:
A. O. Kashkarov, É. R. Pruuel, K. A. Ten, I. A. Rubtsov, E. B. Smirnov, M. A. Biryukova
Keywords:
shock waves, structural materials, spall fracture, polycarbonate, magnesium, synchrotron radiation
Page:
1753
PROJECT OF THE OPTICAL DIAGRAM OF THE SYNCHROTRON RADIATION STATION ON THE RING SOURCE OF PHOTONS SKIF TO STUDY THE CHEMISTRY AND KINETICS OF FLAME COMBUSTION PROCESSES AND PYROLYSIS
The project of the station of synchrotron radiation of the second stage Plamya-2 for the Siberian ring photon source
SKIF is based on the experience gained during the development of the station "Plamya" on the storage ring VÉPP-4
at the Siberian Center for Synchrotron Radiation (SR). The station is designed to study the processes of combustion
and thermal decomposition of various organic compounds by the method of photoionization mass spectrometry
using vacuum ultraviolet (VUV) synchrotron radiation. The use of selective photoionization by VUV radiation in
the molecular beam method of sampling from the reaction zone in fl ames or pyrolyzers makes it possible to identify
and quantify the concentrations of atoms, radicals, and other labile and short-lived compounds, which provides key
information on chemical transformations under conditions of high-speed combustion and thermal decomposition.
The paper considers the possibility of using various SR generators available on the SKIF storage ring, as well as
the optical scheme of the station and the conceptual design of its front-end. The experimental results of measuring
photon fl uxes for the Plamya station and the calculated photon fl uxes on the sample for the Plamya-2 station are
also presented.
Author:
K. V. Zolotarev, D. A. Ivlyushkin, O. P. Korobenichev, A. D. Nikolenko, A. N. Shatokhin, A. G. Shmakov, O. V. Netskina
Keywords:
vacuum ultraviolet, VLS-grating, synchrotron radiation (SR), photoionization, mass spectrometry, fuel, combustion, thermal decomposition
Page:
1760
INVESTIGATION OF THE STRUCTURE OF GAS HYDRATE DEPOSITS BY X-RAY TOMOGRAPHY AND ACOUSTIC SOUNDING METHODS
Within the framework of the program drawn up for the development of the nondestructive methods of studying the properties of heterogeneous materials, the studies were carried out to compare the data on the structure of xenon gas hydrate deposits, obtained by the x-ray microtomography method, with the speed of propagation of acoustic waves in them. The xenon gas hydrate was generated in a water-sandy medium at a temperature of +3o
C and a pressure
of 1 MPa in an experimental cell specially manufactured for these investigations. The obtained three-dimensional
x-ray images of the structure with a spatial resolution of about 3 μm made it possible to clearly distinguish xenon
gas hydrate against the background of the water-sandy medium. The results of investigations have shown that the
hydrate is formed by enveloping sand granules, distributing unevenly in the body of the experimental cell. The data
obtained by acoustic sounding are in good agreement with the data on the microstructure. A characteristic increase
in the velocities of longitudinal waves from 1.048 km/s to 1.564 km/s, caused by the cementation of sand with xenon
hydrate, is observed
Author:
K. É. Kuper, A. N. Drobchik, A. A. Duchkov, G. A. Dugarov, M. R. Sharafutdinov
Keywords:
gas hydrates, x-ray tomography, synchrotron radiation, acoustic properties of hydrate-containing media
Page:
1767
EXPERIMENTAL INVESTIGATION OF THE EFFECT OF LASER TREATMENT ON THE RESISTANCE OF A CERMET COATING TO A HIGH-SPEED IMPACT
For the fi rst time, experimental investigations of the resistance of a cermet coating formed by a combined method (cold gas-dynamical spraying with subsequent laser treatment) to high-speed impact was carried out. It is shown that as a result of laser interaction of TiAl–B4C with cold gas-dynamically deposited coating, boron carbide particles dissolve in the metal matrix, and secondary phase compounds of TiC and TiB2 are formed. Measurement of microhardness showed that created cold gas-dynamically deposited coating, involving B4C, Ti, and Al, has a microhardness of 466.3
HV0.3, while the microhardness of a coating after laser treatment is equal to 1331.3 HV0.1. Investigation of highspeed impact has shown the infl uence of formed coatings on the size of the crater in the substrate. It is also shown
that the created cermet coating (cold gas-dynamical deposition + laser radiation) decreases the crater depth in the
substrate by more than twice, with the crater width decreasing by 1.4 times compared with a sample without coating
Author:
V. M. Fomin, A. A. Golyshev, A. G. Malikov, A. A. Filippov, V. S. Shikalov, M. A. Yadrenkin, A. M. Orishich
Keywords:
laser radiation, cold gas-dynamical deposition (CGDD), boron carbide, impact interaction, crater formation
Page:
1773
NUMERICAL ANALYSIS OF THE DIMENSIONS OF SPACERS FOR LASER WELDING OF PLATES OF POROUS METALS
A mathematical model of nonstationary processes of laser welding of porous metals with the use of a spacer placed
between the ends of the plates to be joined has been developed. The infl uence of the dimensions of a spacer from
nonporous metal on the quality of the produced joints and the morphology of the weld has been investigated.
Dimensions of the spacers to obtain surface joints with the bead or fl ush-mounted with the welded plates have been
determined numerically. Characteristics of the joints of porous titanium and steel plates that have been calculated
using metal spacers, are in satisfactory agreement with the results of conducted physical experiments. This confi rms
the adequacy and reliability of the proposed model.
Author:
V. N. Popov, A. N. Cherepanov
Keywords:
porous metals, laser welding, spacer, numerical modeling
Page:
1780
WELDING OF POROUS PLATES WITH COMPACT ONES OF GREATER THICKNESS WITH THE USE OF NANOMODIFYING ADDITIVES
Experimental investigations were carried out to study permanent connection between porous and compact titanium
and stainless steel plates of various thicknesses attained with the use of continuous CO2 laser radiation. It has been
established that in order to obtain a high-quality butt joint of plates, it is necessary that the end layer of a compact
plate be penetrated through when the axis of the laser beam is shifted from the interface of the parts by a certain
distance, which is necessary for the impregnation of the welded zone of the porous part with molten metal. The use
of modifying additives increases the dispersiveness and uniformity of the weld structure, which has a positive eff ect
on its mechanical characteristics.
Author:
A. N. Cherepanov, V. O. Drozdov, A. G. Malikov
Keywords:
laser welding, porous metals, nanomodifi cation, structure, mechanical characteristics
Page:
1788
DESTRUCTION OF HETEROGENEOUS LASER WELDED JOINTS OF ALUMINUM–LITHIUM AND TITANIUM ALLOYS
A comprehensive study has been made of the destruction of welded joints of the titanium alloy VT20 of a Ti–Al–Zr–
Mo–V system and high-strength aluminum–lithium alloy V-1461 of an Al–Cu–Li system. The welds were obtained
by the method of laser welding with diff erent values of displacement of the laser-beam path from the butt joint of the
materials in the direction of the VT20 alloy. On the basis of mechanical tests, recording of the process of destruction
of the welds in the infrared range, and analysis of fractures using scanning electron microscopy (SEM), and energy-dispersive x-ray spectroscopy (EDX), the authors have established a value of displacement of the laser beam, at
which best mechanical properties of the weld are attained, and also the elemental-phase weld structure corresponding to these properties.
Author:
E. V. Karpov, A. G. Malikov, A. M. Orishich
Keywords:
laser welding, titanium alloy, aluminum–lithium alloy, destruction, thermography of destruction of the weld, elemental-phase composition
Page:
1793
MICROSTRUCTURE AND MECHANICAL PROPERTIES OF A (TiB + TiB2 + TiC)/Ti‒6Al‒4V COMPOSITE MATERIAL FORMED IN THE PROCESS OF IN SITU SYNTHESIS IN SELECTIVE LASER MELTING
A study has been made of the physicomechanical properties of a heterogeneous material based on TiB, TiB2, TiC, and B4C ceramics and a Ti‒6Al‒4V metal alloy formed by the method of selective laser melting. Consideration has been given to the infl uence of TiB, TiB2, TiC, and B4C ceramic particles produced by in situ synthesis in the process of laser
action on the microstructure and hardness of the formed metal-matrix composite. Basic mechanisms of variation in
the microstructure to form secondary ceramic inclusions were discussed and microhardness measurements at a
macro- and nanolevel were carried out. It has been established that ceramic particles formed as a result of the in-situ
synthesis improve sharply the hardness of the metal-matrix composite depending on the composition of the ceramics.
Author:
A. A. Golyshev, A. G. Malikov, V. M. Fomin, A. A. Filippov, A. M. Orishich
Keywords:
laser welding, titanium alloy, aluminum–lithium alloy, destruction, thermography of destruction of the weld, elemental-phase composition
Page:
1793
OPTIMIZATION OF THE PARAMETERS OF ADDITIVE GROWING OF FUNCTIONALLY HETEROGENEOUS NICKEL-BASED MATERIALS
Optimization of the parameters of laser cladding of an N85Yu15 nickel-alumide powder to obtain single tracks
has been carried out. In the course of the experiment, the authors changed the laser-radiation power, the scanning
velocity, and the position of the focus of the laser beam relative to the surface of the powder layer. It has been found
that the dimensions of single tracks decrease as the scanning velocity grows. The dependence of the geometric
characteristics of single tracks on the temperature of the melt pool has been investigated. The microhardness of
the obtained specimens correlated with the quantity of energy imparted to the powder layer and to the melt-bath
temperature. The microstructure of single tracks has been investigated. It has been established that the set of
experimental data is described, in generalized space and energy coordinates, by the linear dependence. With account
taken of the obtained data, multilayer objects were clad, an analysis of the elemental composition of the specimens
has been made, and elemental mapping has been performed.
Author:
M. A. Gulov, A. G. Malikov, A. A. Filippov
Keywords:
additive technologies, laser cladding, optimization, aluminum nickelide, single track, selective laser welding, microhardness
Page:
1809