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The article presents the research results on obtaining coatings on steels 1030 and AISI 420 by the method of electrospark deposition and subsequent smoothing by means of ultrasonic surface plastic deformation (USPD). Intermetallic alloys consisting mainly of NiAl and Ni3Al phases were used as materials for obtaining coatings. It was found that the coatings consist of columnar crystallites of complex composition and have high plastic properties. To ensure the minimum parameters of the surface roughness of the obtained coatings, it is necessary to carry out 3-6 times of ultrasonic surface treatment.

The paper presents the research results on the production of doped composite materials by the method of out-of-furnace liquid-phase self-propagating high-temperature synthesis using oxides and mineral concentrates containing Zr and W as a charge. The positive experience of producing ingots of intermetallic alloys based on the Ni-Al system in one stage of the reduction process of joint metallothermy is shown. The use of Zr in the charge leads to grinding of microstructure of the ingots and the formation of intermetallic compounds containing Zr. The additional use of C, B2O3, and W in the charge results in the formation of complex borides and tungsten carbides in the ingots. Additional introduction of Cr2O3 into the charge is necessary for the formation of W carbides in the nickel aluminide matrix.

The article presents the research results on the problem of the influence of the electric spark discharge parameters and electrode alloys, based on metal matrix materials, used for electro spark deposition (ESD) on the physicochemical and operational characteristics of the coating layer. Experimental dependences of the cathode weight gain, erosion resistance of the anode materials, mass transfer coefficient, wear resistance of the coating, and their mathematical expressions with a reliability criterion of at least R2> 0.9044, are obtained. It is established that, after steel 45 sample has been treated by ESD with metal-matrix materials, the hardness of its surface increases 6 times on the average and the wear resistance – 2 times. The best values of wear resistance at all the modes under investigation have been obtained for the anode material NiO-Zr-TiO2-Al. Data series of cathode weight gain (ƩΔc), erosion resistance of anode materials (ƩΔа), mass transfer coefficient Кmt, coating wear resistance after ESD (Ʃcwr), coating formation efficiency (γcfe), ESD energy efficiency (γeef), are also obtained. These data can be recommended for achieving the required parameters of the ESD on steels using metal-matrix materials.

Coatings were obtained by the method of electrospark deposition (ESD), using Ni-Al intermetallic alloys, steel having been used as cathodes. The structure of samples preliminarily, coated with nickel aluminides of various phase compositions (NiAl, Ni3Al), was investigated. In addition to the indicated anode materials, a complex alloyed metal matrix alloy obtained by the method of self-propagating high-temperature synthesis, was used. It was established that the coating microstructure consisted of columnar crystallites, vertically oriented to the cathode surface. X-ray microanalysis of the transverse sections showed a change in the composition of crystallites along their height. It was found that the content of the cathode components decreased from the surface of the sample to the upper part of its coating, however, the content of the anode components increased. The revealed regularities indicate the fact that the coating structure obtained at ESD, was formed through the stage of liquid-phase mixing, which explained high coating adheasion. The mechanisms of structure formation of both single-layer and two-layer coatings proved to be identical.

In order to obtain high-quality metal products with the desired properties (process stability) using the combined methods of metal casting and deformation, it is necessary to take into account the specific parameters of this process and the fact that the metal in the crystallizer stays simultaneously in several physical states: liquid, liquid-solid, solid-liquid and solid. Structurally, the mold consists of four walls moving relative each other along a given sophisticated trajectory. The object of the research is the production technology from non-ferrous alloys using the combined method of continuous casting and metal pressure treatment. The thermal processes occurring in the mold of a continuous horizontal metal casting and deformation installation (CHMCDI) during the formation of metal products have been examined as a research subject. The methods of physical modeling of the thermal processes which take place in the system “crystallizing metal-tool deformation” under different conditions of the mold cooling (using closed-perforated tubes and straight-flow tubes) have been used. Subsequent data processing of the full factorial experiment using the least square method as well as solving the optimization problem by using the Pareto principle of optimality made it possible to determine the optimal parameters for the process of obtaining metal products from aluminum alloys (TV = 40 oС; рv = 0.7 kg / cm2; SR = 5.8), which have been confirmed by the results of the experimental test on obtaining the strip from technical aluminum AD0 strip with a cross section of 40–12 mm.

The results of experimental studies of a new method for turning billets from thermoplastic polymers such as caprolon and fluoroplastic are presented. The technical essence of the method is in workpiece advanced processing by ultrasonic vibrations using preliminary machining. Experimental studies were carried out on a lathe which is equipped with an ultrasonic oscillatory system. Roughness level profilograms of the caprolon and fluoroplastic treated surfaces are used for visual and operational control of the turning process. The results of the experimental verification of the developed method confirmed the expediency of its implementation since the use of advanced ultrasonic treatment during turning of thermoplastics leads to a decrease in the roughness level of the treated surface of the part as evidenced by the values ​​of roughness parameters and the type of chips obtained.

Composite alloys of nickel aluminides doped with zirconium were obtained by the out-of-furnace aluminothermic reduction method from nickel oxides and mineral concentrate, mainly containing zircon. When the content of Zr is 0.5 and 3.5 wt%, grinding of the Al3Ni2 phase is observed, while at 1 and 2 wt%, the phase size corresponds to an alloy without Zr. Scanning electron microscopy of the multiphase structure of the ingot by points showed that with the increase of Zr in the content of the alloy the number and variety of the forms of Zr-doped nickel aluminides lineally grow.

To reduce the coating roughness on 420 stainless steel, an abrasive free ultrasonic burnishing process (UBP) was used. Coatings were obtained by the method of electrospark deposition (ESD) using Ni-Al intermetallic alloys. The effect of the number of the UBP line passes on the parameters and structure of the surface to be processed was investigated. The structure of samples preliminarily coated with nickel aluminides of various phase compositions (NiAl, Ni3Al, Ni3Al2) was investigated, followed by the UBP treatment over the entire surface 6 times. It was established that the coating formed by Ni3Al2 had the highest plastic properties.

This paper reports the preparation of Al–Zr–W aluminum-matrix alloys containing reinforcing inclusions of various phases. The alloys have been produced by the aluminothermic reduction of starting mixtures consisting of zirconium and tungsten oxides in the first stage and of baddeleyite and scheelite mineral concentrates in a second stage. According to our experimental data, the use of baddeleyite and scheelite instead of zirconium and tungsten oxides in the starting mixture produces no significant changes in the elemental composition of the alloy: the total zirconium and tungsten content of the alloy is 31–32 wt %. Characterization of the alloy prepared using the mineral concentrates has shown that the aluminum matrix contains inclusions of the Al3Zr and Al4W intermetallic phases and a small amount of the ZrN nitride. The volume fraction of the inclusions in the alloy is 32–38%. Most of the structural constituents of the alloy contain a small amount of unwanted silicon and iron impurities (~3%), which originate from the mineral concentrates. In the future, to reduce the impurity concentration we plan to use technological approaches that will ensure preliminary purification of mineral concentrates.

Results are presented for experimental study of a new method for turning workpieces of thermoplastic polymers (caprolon and fluoroplastic), including workpiece advance treatment with ultrasonic vibration. The expediency of using this method is confirmed since advance ultrasonic treatment makes it possible to provide a reduction in the level of workpiece surface roughness, and this is indicated by roughness parameter values and forms of shaving obtained.

Intermetallic alloys in the Ni–Al system strengthened through inclusions of molybdenum and tungsten borides by means of sequential exothermic reactions in a two-layer charge are fabricated. NiAl and Ni2Al3 intermetallic phases and molybdenum (Mo2B5) and tungsten (W2B5) borides are identified in alloys by the methods of X-ray diffraction and elemental analysis. It is established that Mo2B5 and W2B5 inclusions are characterized by high values of microhardness (Mo2B5—24.4 GPa and W2B5—29.2 GPa).

Cast NiAl–Mo2C and NiAl–WC alloys have been prepared by self-propagating high-temperature synthesis involving the reduction of starting metal oxides. Synthesis conditions have been found experimentally. The elemental and phase compositions of the alloys have been determined and their microstructure has been studied. The composites have been shown to have higher microhardness than do NiAl intermetallic alloys containing Mo and W inclusions.

The research provides facts about the surface plastic deformation (SPD) effect on the coatings surface parameters formed by electro-spark alloying (ESA). The complex for nonabrasive ultrasonic finishing (NUF) was used as the installation for SPD. It was found out that when processing bronze by NUF several passes of indenter were needed to provide substantial decrease of the surface roughness parameters. The NUF effect on roughness parameters of intermetallic coatings on steel 20X13 was studied. NUF proved to be perspective when it is necessary to reduce the number of transverse cracks in the coatings formed by ESD method. In order to assess the efficiency of coating surface treatment by NUF method the use of additional parameters Rk, Rpk, Rvk alongside with Ra are recommended as they allow assessing the resulting surface as triple. It is found out that the number of passes during the processing of intermetallic coatings should not exceed 6. For achieving maximum processing efficiency it is necessary to take into consideration the initial roughness value.

The authors study obtaining a composite material NiAl - Mo2B5 while carrying out thermally coupled reactions of self-propagating high-temperature synthesis with a deoxidizing aluminothermal stage. The authors established ultimate and phase composition of the obtained composite. The microstructure is studied. It is shown that the composite consists of the intermetallic phase NiAl with Mo2B5 inclusions.

We have examined conditions for the preparation of a NiAl + MoB + Mo composite material through thermally conjugate self-propagating high-temperature synthesis reactions with an aluminothermic reduction step. The reduction reactions involved have been thermodynamically assessed, and the elemental and phase compositions of the obtained materials have been determined. The composite has been shown to consist of the intermetallic phase NiAl with β-MoB inclusions, which have high microhardness values (26.32 GPa).

Fabrication conditions of NiAl, NiAl–Cr, and NiAl–Cr–Mo–W alloys by joint aluminothermic reduction of initial metal oxides are investigated. Thermodynamic characteristics of accompanying reactions are determined. The temperature dependence of the change in the isobaric potential (ΔG°, kJ/mol) of reduction reactions of oxides points to the high formation probability of alloys. It is revealed by differential thermal analysis that the reduction of metal oxides enters the active phase after aluminum is melted at ~650°C and progresses according to the heterogeneous mechanism in a temperature range of 800–1100°C. The optimal composition of the initial charge, which provides the maximal yield of metals into alloys, is established. It is found experimentally that the yield of metals into alloys constitutes 85–92 wt %. Synthesis products are identified by the elemental and X-ray phase analyses as intermetallics of the Ni–Al system, which contain inclusions of chromium, molybdenum, and tungsten. It is shown that the concentration of inclusions varies in a range of 1.5–6.5 wt %. The microhardness of alloys is determined to vary from 3546 to 7436 MPa, depending on the content of alloying elements.

The results of experimental studies of a new method for turning billets from thermoplastic polymers such as caprolon and fluoroplastic are presented. The technical essence of the method is in the workpiece advanced processing by ultrasonic vibrations using preliminary machining. Experimental studies were carried out on a lathe which is equipped with an ultrasonic oscillatory system. Roughness level profilograms of the caprolon and fluoroplastic-treated surfaces are used for visual and operational control of the turning process. The results of the experimental verification of the developed method confirmed the expediency of its implementation since the use of advanced ultrasonic treatment during turning of thermoplastics leads to a decrease in the roughness level of the treated surface of the part as evidenced by the values of roughness parameters and the type of chips obtained.

Results are presented for experimental studies of a new turning method for caprolon workpieces. The essence of the method involves a reduction in workpiece surface layer breaking resistance in the cutting area by prior treatment with surface-active substances followed by turning. It is demonstrated by experiment that prior workpiece treatment with SAS provides an improvement in turned surface quality as indicated by a reduction in roughness parameters by a factor from 2.5 to 4.

The effect of treatment time in SAS on the strength of getinaks, textolite, and caprolon is studied. An effect of polymer material processing weakening after holding in toluene and acetone is detected. It is proposed to use preliminary polymer material chemical treatment in order to reduce surface layer breaking resistance during cutting.

Results are provided for experimental study of the deformation and failure mechanism for polymer materials with specimen uniaxial tension. An acoustic emission method is used for quantitative evaluation of the test process. Comparative analysis is provided for volumetric structural changes in specimens and corresponding acoustic emission elastic wave parameters for brittle and ductile materials.

A foundry-forging module allowing one to obtain a deformed profile of a specified cross section from molten metal in a continuous mode is developed and fabricated. The data of metallography investigations of continuously cast deformed blanks (CCDB) from technical copper and their comparison with structures of cast test samples are given. The results of estimation of the dimensional geometric accuracy of the CCDB samples are presented.

The reduction conditions of the oxygen compound of molybdenum to metal powder using aluminum and magnesium in a sodium chloride solution are investigated. A thermodynamic evaluation of the reduction reactions is given. It is found that, in order to end up with a 95–97% yield of the powders, an excess of ∼30% of the reducing agent with respect to the calculated one is necessary. In this case, the content of impurity elements does not exceed 3%. The influence of obtaining conditions on the granulometric characteristics of the powder is established. It is shown that powders with a larger specific surface (64.4 × 105 m−1) are formed with the use of aluminum in concentrated solutions of the starting compound in the NaCl melt.

This paper deals with the investigation of complex-alloyed nickel aluminides obtained from oxide compounds by aluminothermic reduction. The aim of the work was to study and develop the physicochemical basis for obtaining complex-alloyed nickel aluminides and their application for enhancing the properties of coatings made by electrospark deposition (ESD) on steel castings, as well as their use as grain refiners for tin bronze. The peculiarities of microstructure formation of master alloys based on the Al&ndash, TM (transition metal) system were studied using optical, electronic scanning microscopy and X-ray spectral microanalysis. There were regularities found in the formation of structural components of aluminum alloys (Ni&ndash, Al, Ni-Al-Cr, Ni-Al-Mo, Ni-Al-W, Ni-Al-Ti, Ni-Cr-Mo-W, Ni-Al-Cr-Mo-W-Ti, Ni-Al-Cr-V, Ni-Al-Cr-V-Mo) and changes in their microhardness, depending on the composition of the charge, which consisted of oxide compounds, and on the amount of reducing agent (aluminum powder). It is shown that all the alloys obtained are formed on the basis of the &beta, phase (solid solution of alloying elements in nickel aluminide) and quasi-eutectic, consisting of the &beta, &prime, phase and intermetallics of the alloying elements. The most effective alloys, in terms of increasing microhardness, were Al-Ni-Cr-Mo-W (7007 MPa) and Al-Ni-Cr-V-Mo (7914 MPa). The perspective is shown for applying the synthesized intermetallic master alloys as anode materials for producing coatings by electrospark deposition on steel of C1030 grade. The obtained coatings increase the heat resistance of steel samples by 7.5 times, while the coating from NiAl-Cr-Mo-W alloy remains practically nonoxidized under the selected test conditions. The use of NiAl intermetallics as a modifying additive (0.15 wt. %) in tin bronze allows increasing the microhardness of the &alpha, solid solution by 1.9 times and the microhardness of the eutectic (&alpha, + &beta, phase) by 2.7 times.

Measured acoustic characteristics of some structural materials subjected to different types of thermal treatment are presented. Averaging of the ultrasonic waves’ phase when a probe’s dimensions and measurement base increase is observed.

The laws of modification of the microstructure of a copper contact wire, its strength, and the acoustic parameters are investigated as functions of the heating temperature. The acous- tic and strength characteristics of samples of wires subjected to various loads are compared.

Probable mechanisms of destruction of an aerial contact wire are considered and dependences between variations of structural parameters of the wire material and its acoustic properties under a thermal in uence are established.

A circuit and the structural features of apparatus for the synchronous recording of the electrical and optical characteristics of spark discharges, which occur between two electrodes at low voltages, are described. The parameters are recorded in digital form with a discreteness of 4 μsec.