CONTENTS

 

Effect of energy fluxes on materials

 

A.B. Tsepelev, A.S. Ilyushin, T.Yu. Kiseleva, E.A. Brovkina, V.N. Melnikov

Radiation-induced changes of the structure and mechanical properties

of Fe-Mo alloy under electron irradiation .................................................................................................................................... 5

By X-ray diffraction, the radiation-induced changes in the structure and phase state of a model Fe-5% Mo

alloy have been studied after electron irradiation at room temperature and 400°C. The observed effects of

radiation softening of the alloy is explained by decrease of Mo concentration in solid solution and increasing

 the number of lattice defects. This conclusion is confirmed by the shift of 200 diffraction maximum toward

larger angles and its broadening. Irradiation leads to oxidation of the alloy, and additional annealing at 400°C

causes the formation of spinel Fe2MoO4 and strengthening of the alloy.

Keywords: Fe-Mo alloy, solid solution, electron irradiation, radiation softening, structure and phase transformations.

 

S.P. Malyukov, Yu.V. Klunnikova, A.V. Sayenko, T.H. Bui

Simulation of laser treatment induced temperature fields and internal stresses in sapphire wafer ............................................ 11

The model of the laser treatment process is built for estimation of the temperature and thermal stresses

distributions in the volume of laser-irradiated target. By means of the solution of thermal conductivity

equation and with the use of the ANSYS program package for finite element analysis, the temperature

and thermal stresses distributions were calculated for sapphire wafers irradiated by 100 W Nd:YAG laser.

The calculations are as applied to the problem of laser-controlled cleavage of sapphire wafers.

Keywords: laser-controlled thermocleavage, sapphire wafers, numerical simulation.

 

I.V. Ushakov, A.Yu. Batomunkuev

Simulation of laser plasma induced processes in the surface layers

of multicomponent amorphous-nanocrystalline alloy ................................................................................................................. 17

By computer simulation, peculiarities of the heating and cooling of the thin film specimens irradiated with

a series of laser pulses have been studied. The thickness of the surface layer strengthened due to realization

of the processes of mechanical stresses relaxation, recrystallization, and plastic deformation of material is

determined. Selective impact of laser plasma on the material areas with defects acting as stress concentrators

 has been demonstrated. It is shown that the depth of the treated surface layer can run up to 20-25% of the

total thickness of the thin specimen. Comparison of the simulation results with experimental data on the

effect of pulsed laser irradiation on the properties of thin ribbon specimens from amorphous-nanocrystalline

Co71,66B4,73Fe3,38Cr3,14Si17,09 alloy was carried out.

Keywords: laser treatment, computer simulation, laser strengthening, nanocrystalline metal alloys, laser heating.

 

I.G. Tananaev, V.I. Roldugin, G.E. Folmanis, L.V. Kovalenko,

E.E. Kazilin, M.A. Fedotov, V.A. Volchenkova

Fragmentation of selenium dispersed phase by laser pulses ...................................................................................................... 23

An interaction of Se particles in a colloidal solution with a laser radiation has been investigated. It is

ascertained that the internal despersed phase desintegration and formation of a large number of nanosized

 Se particles are ocurred under laser irradiation of aqueous colloidal solution.

Keywords: laser ablation, colloidal solution, selenium, nanoscale agents.

 

Functional coatings and surface treatment

 

V.I. Kalita, A.A. Radyuk, D.I. Komlev, A.Yu. Ivannikov, V.S. Komlev, K.Yu. Demin

Boundary between hydroxyapatite coating and titanium substrate ............................................................................................. 27

Effect of Ti substrate heating up to 300 and 550°C on microhardness of hydroxyapatite (HA) plasma

coating, Ti substrate, and coating–substrate boundary in specimens in different conditions (as sprayed,

after hydrothermal (650°C/3 h) and vacuum thermal treatment at 800 and 1000°C/3 h) has been investigated.

It is shown that preliminary heating of the substrate up to 550°C leads to the boundary microhardness

 increasing from 2.32 to 3.07 GPa while the following heat treatment has a weak influence on that.

After heat treatment, microhardness of HA coating is increased from 3.0 to 3.8 GPa and microhardness

of Ti substrate near the boundary is increased from 2.5 to 6.9 GPa. Slight effect of heat treatment on the

boundary microhardness is explained by conservation of the boundary structure formed under HA plasma

spraying on heated substrate. By AES method, distribution of chemical elements in the area of the

coating–substrate boundary is studied.

Keywords: plasma sprayed coatings, hydroxyapatite, Ti substrate, heating of substrate, coating–substrate boundary,

 hydrothermal and thermal treatment, microhardness.

 

O.B. Perevalova, A.V. Panin, Yu.F. Ivanov

Electron-beam treatment induced changes in the solid solution parameters and microstructure of technical titanium ............. 36

Elemental composition, grain structure, solid solution lattice parameters, and phase composition of the

surface layers of technical Ti have been investigated after electron-beam treatment with a different energy

 density of the beam. By means of SEM, TEM, X-ray diffraction, and EBSD analysis, a lamellar structure

formation in the surface layer was ascertained. A lateral dimension of the structure consisting plates is

found to be increased as the energy density of the beam is grown. Formation of the subgrain structure

and deformation twins was observed under the electron beam modified layer.

Keywords: electron beam, technical titanium, structure analysis, microstructure, microdistortions, deformation twins.

 

S.S. Vinogradov, S.A. Demin, O.G. Kirillova

Anticorrosion inorganic composite coating of aluminum–phosphates system ........................................................................... 46

An inorganic composite aluminum–phosphates coating is developed for corrosion protection of carbon

steels. The coating acquires the electroconductive properties and has a high protective capability (over 7200

hours in a salt spray chamber) after mechanical grinding of the surface. Electrochemical tests confirm an

anodic type of the coating relative to carbon steels. Composite coating investigated possesses a good

adhesion with metallic substrate and has a good water- and oil resistance. Results of the mechanical tests

 evidence the possibility of the use of the composite coating for corrosion protection of high-strength

carbon steels.

Keywords: inorganic composite coating, coating based on phosphates and aluminum powder, protective property,

grinding, electrochemical tests, mechanical tests, water resistance, oil resistance.

 

A.I. Gorunov

Deposition of wear resistant Ni-based coatings by supersonic laser cladding ........................................................................... 59

The regularities of the formation of Ni-based coatings produced by supersonic laser deposition has been

studied. The technology for controlled deposition of the coatings with required structure and properties is

proposed. Substantial adhesion of the coating and substrate is ensured by mixing of deposited material

and basic metal. High strength of the coating deposited is due to penetration of the powder particles into

the matrix material at a supersonic speed.

Keywords: direct laser deposition, supersonic laser cladding, nickel alloy, microstructure, roughness, hardness.

 

A.V. Panarin, V.V. Semenychev

Tribological behavior of the carbide-chromium coating ............................................................................................................ 65

Specimens from åðó casting high-silicon aluminum alloys and titanium alloy with deposited pyrolytic

carbide-chromium coatings were subjected by tribological tests in dry friction conditions. It has been

shown that the wear of the coatings was in 2 and 3 times lower than that of the riders from the structural

steel or Ti alloy respectively. During the test, an uniform wear of the coatings with the formation of a

single cohesive cavities. Metallographic studies found the appearance of the individual cracks, do not

cause peeling of the coating from the substrate. Microhardness of the coating is about 15 GPa, which

is 4-6 times higher that of the structural steel and titanium alloy.

Keywords: carbide-chromium coating, casting aluminum alloys, coefficient of friction, wear, microhardness,

metallography.

 

Composite materials

 

F.I. Akhmedov

Electrophysical properties of composites on the base of nonpolar polypropylene

and polar polyvinylidene fluoride filled with alumina ................................................................................................................. 71

Effects of α-Al2Î3 filler content on electrophysical properties of composites on the base of nonpolar

polypropylene and polar polyvinylidene fluoride have been investigated. It is ascertained the temperature

behavior of electroconductivity, permittivity, and dielectric loss of the composites are changed against of

the filler content, but for all that the properties of different composites were changed in different ways.

It follows from the results the electrophysical properties of the composites can be controlled purposefully

by the change of the filler introduced content.

Keywords: dielectric, composite, polypropylene, alumna, polyvinylidene fluoride, filler.

 

A.V. Kazurov, N.A. Adamenko, S.M. Ryzhova

Effect of explosive treatment on electrical resistance of polyimide based composites with disperse bronze ............................... 77

Effect of the method of production, volume content of disperse bronze, and test temperature on electrical

resistivity of polyimide based composites have been investigated. It was ascertained that the explosive

treatment and subsequent sintering in a closed volume leads to decrease of the composite electrical resistance

compared to that for composites obtained by isostatic pressing. The effect observed is connected with

enhancement of physical and chemical interaction between a polyimide matrix and bronze particles as well

as with polyimide structure changes in the interface layer which are occurred under explosive treatment.

Keywords: polyimide, powder bronze, explosive treatment, composite, sintering, electroresistance.

 

New methods of treatment and production of materials

with required properties

 

N.M. Barbin, M.R. Shavaleev, D.I. Terentyev, S.G. Alekseev

Thermodynamic analysis of U-, Pu-, Am- and Eu-aided reactions in the process of the heating

of radioactive graphite in nitrogen medium ................................................................................................................................ 83

On the base of thermodynamic computer simulation, the equilibrium constants and temperature

dependencies  of the Gibbs energy have been calculated for the reactions occurred with U, Pu, Am,

and Eu participation during the heating (combustion) of radioactive graphite in nitrogen medium.

The balance of radionuclides in the system is determined in the temperature range of 370-3370 K.

An optimal temperature regime of graphite heating required for solid radionuclides conversion

into gaseous state and its removal from the graphite is offered.

Keywords: thermodynamic simulation, equilibrium constant, Gibbs energy, radioactive graphite,

radionuclides, waste treatment.