The paper presents an experimental study of lining the energy-intensive planetary mill internal surfaces with silicon powder. The experimental dependences were determined for the amount of grinded material used for lining on the time of mechanical activation (MA). The lining speed constant was defined in two ways for short and long duration MA using analytical formulae and experimental results obtained with the inverse problem method. The first one was based on the analysis of experimental curves describing the lining dynamics with the least square method. The second one suggested the constant value measurement according to the tangent of the angle between the X-axis and the straight lines that approximate the experimental curves at the initial period of grinder operation. It was found that the increase in MA duration led to deceleration of mill lining with silicon powder. It was also found that the value of the lining speed constant lowered as the MA time increased. Therefore, the theoretical calculations adequately fit to experimental data.

The results of high-temperature electrochemical synthesis are presented for intermetallic nickel and holmium powders. The optimal conditions for the synthesis of these compounds were found, including: temperature of the electrolytic process (923–1073 K), cathode current density (0,5–1,9 A/cm2) and the electrolytic bath concentration ratio, mol.%: KCl(48,25÷49,5)–NaCl(48,25÷49,5)– HoCl3(0,5÷3,0)–NiCl2(0,5÷2,5). The resulting powder composition was studied by the X-ray diffraction analysis and scanning electron microscopy methods.

А process for producing an effective composite uranium-gadolinium fuel was developed in the laboratory. This fuel will help to improve technical and economic performance of nuclear power plants. Based on the analysis of the results obtained, the implementation of the proposed method in a manufacturing environment was substantiated. Methods for preparation and production of the raw materials for the fabrication of gadolinium oxide were described. The essential characteristics of promising composite uraniumgadolinium fuel pills were defined experimentally. Based on these characteristics, the final specifications for the fuel pills were formulated.

A computer simulation technique for the process of non-compact titanium raw material compaction is considered. The modified Drucker–Prager plasticity model is used to describe the rheological flow of strained material. It is shown that it is advisable to use an auxiliary curve based on the Bernoulli lemniscate for the identification of the accepted yield model with accuracy acceptable for engineering calculations. It allows reducing the number of experiments required to build piecewise smooth Drucker–Prager yield curve. Plastic deformation of representative volume element of titanium sponge screening in various stress-strain states was studied. The plasticizing effect related to the increase of plastic β-phase while hydrogen alloying was used to improve the formability of non-compact titanium raw materials. Based on theoretical and experimental studies, it was found that the hydrogen alloying provides a denser workpiece at constant temperature and compression force compared to the traditional compression technology of titanium sponge. It is shown that the uniformity of the relative density distribution in the axial section of the workpiece increases with the additional hydrogen alloying.

The paper studies how the pattern and conditions of Ta–Zr–C reaction mixture mechanical activation affect the phase composition and microstructure of the charge and synthesis products. It was found that the microstructure of the charge processed in a planetary centrifugal mill for the same time periods strongly depends on the MA patterns with the different sequence of the components addition. Phase composition of the mixtures is the same since no formation of chemical reaction products in the mill drums was detected. The increase in processing time for all of the tested MA patterns leads to the growth of crystal tantalum lattice microstrain and reduces its coherent scattering area, indicating the increasing amounts of stored energy. The study of the activation environment (air, argon or vacuum) impact revealed that with MA in the air the SHS product is practically a single-phase binary carbide (Ta, Zr)C with less than 3 wt.% of ZrO2. The synthesis of the reaction mixtures activated in an oxygen-free atmosphere discovered 3 carbide phases TaC, ZrC and (Ta, Zr)C with no ZrO2 traces. The optimal SHS MA modes were defined which ensure obtaining of 100 % singlephase solid solution (Ta, Zr)C with a lattice parameter of a = 0,4488 nm that corresponds to 15 at.% of ZrC in a binary carbide.

Ti2AlN MAX-phase was synthesized from the powder mixtures of Ti–AlN using the reactionary sintering method. The optimal synthesis mode for the compound containing less than 1 % of TiN impurity phase was determined: isothermal annealing at 1300 °C for 2 hours in argon at a pressure of 3 atm. The preliminary mechanical activation and the reaction synthesis environment were investigated as the factors that can influence the yield of the Ti2AlN phase. It is shown that the activation increases the level of TiN secondary phase. It was also found that the vacuum synthesis does not enable obtaining of single-phase Ti2AlN.

The study describes technological capabilities of self-propagating high-temperature synthesis (SHS) in the production of aluminumbased composite alloys with liquid-phase methods for shaped casting manufacturing. Thermodynamic calculations of reactions between the original components were made and the scheme of their interaction was proposed. The impact of different methods of powdered precursor preparation on the reaction intensity was defined. Comparative data was given for the casting properties of the composite alloys produced using SHS. The production technology was developed for the composite-alloy castings and the results of their pilot testing were presented.

Heat capacity of mechanically activated nano-crystalline carbonyl iron and iron nanocomposite samples with added isoelectronic sp-elements (sp – C, Ge or Sn) with the grain size of about 2–5 nm was determined in the 300–450 K temperature range using the IT-s-400 calorimeter. Thermo-physical studies of the specific heat temperature dependence were performed on 68 at.% Fe – 32 at.% M (M – Ge, Sn) and 95 at.% Fe – 5 at.% С nanocomposites with different mixture compositions. It was shown that penetration of sp-elements into nanocrystalline iron leads to significant changes in the heat capacity over the entire temperature range under investigation. The heat capacity turned out to depend strongly on the introduced sp-element and the degree of disorder in the material obtained.

The article presents the results of the study covering wear resistant electrospark coatings (ESC) made with electrospark deposition of a steel substrate. The iron based amorphous alloy 2NSR (Fe78B12Si9Ni1) and nanocrystalline alloy 5BDSR (Fe78,5Si13,5B9Nb3Cu1) were used as electrode materials. The ESC structure analysis with scanning electron microscopy and X-rays determined that the 2NSR alloy coating is generally amorphous, while the 5BDSR alloy coating has a nanocrystalline structure that is an amorphous matrix with nanocrystals α-Fe. The microhardness of 2NSR alloy electrospark coating was 7279 MPa at a thickness of 30 microns, and 5BDSR — 10147 MPa at a thickness of 33 microns, that is about 1.5 times thicker than the VK6-OM alloy coating. Tribotechnical tests revealed that the 2NSR alloy electrospark coating has wear resistance 4 times higher than that of 5BDSR at the stage of steady wearing. However, its wear rate was 1,3 times higher at the stage of running. Performance tests found that the coating made of 5BDSR nanocrystalline alloy extends the life cycle of cutting machine parts running in abrasive wear conditions by at least 1,4 times.

26 апреля 2016 г. на 86-м году ушел из жизни выдающийся ученый в области порошковой металлургии и материаловедения, основатель проблемной научно-исследовательской лаборатории динамического горячего прессования, заведующий кафедрой металловедения и технологии металлов Южно-Российского государственного политехнического университета им. М.И. Платова, заслуженный деятель науки и техники Российской Федерации, действительный член Международного института науки о спекании, профессор, доктор технических наук, талантливый педагог, замечательный и отзывчивый человек — Юрий Григорьевич Дорофеев.