The results of experimental studies of the AK7ch Al–Si alloy before and after modifying with compositions—(i) the K2ZrF6 industrial modifier, (ii) modifying mixture based on oxides of refractory metals and cryolite, and (iii) the «Arsal 2120» foreign flux – are presented.
It is established that modification of the AK7ch alloy leads to the uniform distribution of eutectics (α-Al + β-Si), structural components, decrease in silicon crystals by a factor of 1,5–2,0 on average, refining, and variation in shape of Fe-containing phases. It is shown that an increase in relative elongation by a factor of 2 and more is characteristics for all modified samples, and the tensile strength, hardness, and density of casts for all the samples are different and has an ambiguous character.

Factors causing the solid-phase dispersion of the particles of alloying elements in the aluminum melt depending on their nature are considered. It is shown that the particles can be fragmented under the effect of uniform tensile stresses appearing due to heating the particles. The reasonability of using additional external effects (for example, magnetic-pulsed treatment of the foundry-alloy melt) in order to intensify the assimilation of silicon in liquid aluminum and provision of microcrystalline structure of the foundry alloy is substantiated theoretically and confirmed experimentally by the example of the Al–20wt%Si foundry alloy.

The influence of antimony ions (Sb3+) in a concentration range of 0,001–0,200 mg/L on the current yield of zinc during the electrolysis of sulfate solutions is investigated. It is established that antimony, in contrast to germanium and tin, promotes an increase in current yield of zinc under definite conditions. This is caused by the fact that the alloy of zinc with antimony, which possesses the potential more positive compared with zinc, is deposited on separate cathode segments, due to which, the discharge of zinc ions proceeds in the depolarization mode with a higher current yield. A decrease in the current yield of zinc with the fraction of antimony higher than 0,2 mg/L is associated with the prevalent effect of galvanic pairs of antimony with zinc over the electrolysis with the depolarization. It is established that antimony enhances the negative effect of cobalt on the current yield of zinc due to the formation of the alloy of cobalt with antimony, on which the isolation overvoltage of hydrogen is lower than on zinc.

A mechanism of extraction of cerium by tributyl phosphate (TBP) from phosphate solutions using model and production solutions containing, %: 26–28 P2O5, 1,2–2,8 SO3, 0,3–0,8 CaO, 0,1–0,4 Al2O3, 0,3–0,4 Fe2O3, and 0,09–0,1 REM(NO3)3. A model solution of phosphoric acid corresponded to the industrial solution of extraction phosphoric acid (EPA) by the content of P2O5 and Ce(NO3)3 and value of pH (0,6). Dependences of extraction parameters on the TBP concentration in o-xylene and concentration of nitrate ions introduced by magnesium and calcium nitrates, which are used as a salting-out agent, are found. The composition of the extracted organic complex of cerium Ce(H2PO4)(NO3)2·TBPorg is determined. A constant of extraction equilibrium and the Gibbs energy of extraction are calculated. It is concluded by the results of the experiment that it is unreasonable to use TBP to extract Ce from phosphoric acid systems without introducing a considerable amount of the salting-out agent.

A procedure of determining the optimal angles of the drawing tool for a three-component billet, which takes into account the presence of the finishing die cylinder and provides a minimal drawing stress, is proposed. The influence of manufacturing parameters on the magnitude of optimal conicity angles of the manufacturing tool is shown. The relationship for the calculation of the optimal drawing, which provides minimal drawing stress, is found for standard dies with a fixed conicity angle.

A fracture locus of copper rolled wire depending on the stressed-state coefficient (k) and Lode–Nadai coefficient (μσ) is constructed. The region of using this fracture locus to calculate the damage is limited by values k < 1,4 and –1 < μσ < 0. To construct the fracture locus, we performed twisting tests of cylindrical samples and tension tests of cylindrical and plane samples in air and in a chamber with a controlled liquid pressure, which was varied from 49 to 375 MPa. The constructed fracture locus will be further used for the calculations of damage of copper rolled wire in drawing processes, by the results of which, recommendations for lowering the wire breakage during drawing will be elaborated.

The results of studying the surface damageability of pure metals found in the course of fatigue tests are described. A character of the rate dependence for resistance of cyclic deformation of metals upon varying the frequency of loading cycles, homological temperature, and
stacking fault energy are described.

There are three main ways to improve the quality of the diamond tool based on the metallic binder: an increase in (i) binder properties, (ii) quality of diamond grains, and (iii) adhesion to diamonds. An efficient method for a simultaneous increase in binder properties and binder adhesion to diamond in the course of sintering the composite materials is proposed in the study. A mechanism of spontaneous formation of the coating based on tungsten carbide on the surface of diamonds in the course of sintering the metal-matrix composite, which contains strengthening particles of tungsten carbide, is investigated. The coating is formed according to the gas-transport reaction mechanism.

Complex investigations into physicomechanical properties and adhesion strength in the «coating–carbide cutting insert» system of 
monolayered (Ti–Al–N) and multilayered (Ti–Al–N/Cr–N, Ti–Al–N/Zr–N/Cr–N) are performed. The advantage of using the latter; which is associated with the passage from the adhesion mechanism of coating destruction to the cohesion mechanism; with an increase in parameters H3/E2 and H/E that characterize the material resistance to plastic and elastic deformation, respectively; is shown. The introduction of chromium into the composition of Ti–Al–N coatings provides a decrease in friction coefficient (from 0,52 to 0,45) and a decrease in probability of adhesion interaction with the treated material. Comparative operational tests of carbide cutting insets (CCI) with coatings under study in the course of continuous cutting steel 12H18N10Т showed that largest wear resistance of Ti–Al–N/Zr–N/Cr–N coatings. Wear tests of CCIs made of VK6NST and TT10K8B alloys with Ti–Al–N/Zr–N/Cr–N coatings in the course of longitudinal turning steel 12H18N10Т and VT20 alloy evidence an increase in their resistance up to a factor of 3,0–3,5 both at low and high cutting rates. These coatings provide an increase in resistance of cutting tool and in milling operations of VT20 titanium alloy at cutting velocity up to 40 m/min.

A mathematical model and algorithm of the hydraulic calculation of the crystallization wall with a complex connection of a periodically repeated system of horizontal and vertical channels are considered. A computer program allowing one to perform the hydraulic calculation of the crystallizer plate having an arbitrary number of channels of various forms and sizes is created based on the developed mathematical model. The possibilities of this software product when designing copper crystallizes to select their geometric parameters and rational regimes of hydraulic operation are shown.