Materials Science Forum Vol. 1022

Abstract: In the Caspian region, the Tengiz oil field has a high content of sulfur, salts and mechanical impurities, which contribute to the rapid deterioration of equipment. The use of titanium alloy allows reducing corrosion wear 2-3 times. Based on the analysis of the design of the slide gate valve, the most exposed parts were identified, which were replaced by Grade 5 titanium alloy. Bench tests of the slide gate valve were put into operation. Laboratory work was carried out to apply titanium-based coatings to steel samples. The result was a structure with a microhardness of 730-810 HV sufficient to protect it against corrosion wear.

Abstract: This study is dedicated to application of x-ray methods to investigate phase formation in contact melting in a Cd-In system after introduction of a small admixture of sodium to cadmium, including cases of electrotransport. Formation of both two-and three-component intermetallic compounds has been established. An attempt is made to explain the results.

Abstract: This study is dedicated to investigating contact melting, including cases of electrotransport is a Sn-Bi system after introduction of a small admixture of indium. It has been shown that the dopant ambiguously influences the rate of the contact melting. The structure of obtained alloys is strongly non-uniform and abounds with dendritic forms. An attempt is made to explain the results.

Abstract: The article presents the results of experimental studies to determine the relationship between the electrolysis modes and the properties of electroplating coatings for mathematical modeling of the dynamics of the electrolytic process (MDEP), described by a system of ordinary differential equations due to the complex relationship of the kinetics of chemical reactions, hydrodynamics and mass transfer in the electrolyte flow, the kinematics of electrode plates, and the influence of the electric field of the "anode-cathode" pair on all these processes. At the same time, the experimental base was a series of full-scale experiments to restore the seats of the root supports of cylinder blocks with electroplated coatings. The final result of the research is the procedure for constructing an optimal resource-saving mode of electroplating, which is a zinc-iron alloy.

Abstract: The experimental study results of the melts concentration dependence of the surface tension of the four-component indium-tin-lead-bismuth system and its constituent binary systems of indium-tin, indium-lead, indium-bismuth, tin-lead, tin-bismuth, lead-bismuth are presented in the paper. It is shown that the concentration dependence of the melts surface tension of the In-Sn-Pb-Bi four-component system can be predicted from the data on ST (surface tension) values of lateral binary systems. Features in the ST isotherms in the form of a minimum are observed only in the indium-tin lateral system from all lateral binaries. A distinctive feature of the detected minimum is that the minimum depth slightly exceeds the experimental error. Therefore, in addition to the fact that the area of average compositions was studied more thoroughly, we carried out the surface tension measurements by two independent methods. The experimental data obtained by both methods coincide within the experimental error and indicate the extremum availability on ST isotherms. Thus, ST experimental studies by two independent methods confirmed the presence of a flat minimum on ST isotherms of the indium-tin binary system increasing the reliability of the obtained data. The obtained outcomes and their comparison with experimental data have shown that the considered models for predicting surface properties based on data due to similar properties of lateral binary systems adequately reflect the experimental dependences. However, the prediction model based on Kohler's method of excess values describes the experimental curves more accurately.

Abstract: The paper describes the synthesis of three new copolymers based on styrene and α-methylstyrene derivatives by radical emulsion copolymerization in an aqueous medium in the presence of an ammonium persulfate initiator and potassium stearate emulsifier. In early study, it was found that copolymers based on methoxy derivatives of styrene have the advanced dielectric properties, as compared to polystyrene and a copolymer of styrene and α-methylstyrene. In addition, the latest scientific literature provides data on the biological activity of styrene copolymers. Thus, the synthesis and study of the properties of new copolymers based on styrene and α-methylstyrene creates a prospect for establishing materials with a unique set of properties differing from their previously studied analogues. The structure of synthesized copolymers is confirmed by IR spectroscopy. Along with this, the paper provides the curves of thermogravimetric analysis, data on dielectric constant and tangent of a dielectric loss angle. A hemolytic effect of copolymers is determined, which indicates biocompatibility and further research perspectives towards their suitability for medical use. A copolymer of sodium 4-styrenesulfonate and α-methylstyrene (the molar ratio of starting monomers is 7:3) is soluble in an aqueous medium, which makes it of higher priority in terms of further study into biological activity.

Abstract: The paper presents experimental results on the dependence of surface tension on the concentration of a suspension of bentonite (0 - 10% by weight). The isotherms σ of aqueous suspensions of bentonite are characterized by local minima in the concentration range of 3-4 mass% of the solid phase. It has been established that a decrease in the average particle size leads to the disappearance of the extremum on the surface tension isotherms. The data obtained led to the conclusion that the most important factors affecting the nature of the isotherms of the surface tension of bentonite suspensions are the degree of dispersion and the presence in the aqueous suspension of bentonite, both colloidal and coarse particles.

Abstract: Based on the interaction of solid and liquid phases in metallic systems, the paper deals with the properties of grain boundary propagation (migration) in solid-state alloys. Using the effect of surface solid-state dispersion enables to obtain composite materials and brazed joints with a required set of physical and mechanical properties. For the first time, the authors investigate the features of boundary migration in type II systems, in which, in accordance with the thermodynamic criterion σ_ss< 2 σ_SL, the grain-boundary propagation is not basically allowed.

Abstract: The polytherms of density, surface tension of the Cu-Al system melts and wetting angles of Ni-Cr, Co-Cr substrates, 25X18H9C2 stainless steel and titanium were studied by the sessile drop method. The drop contour was processed by dint of current information technologies, in particular, using the ImageJ software package [1]. The equations of density polytherms and surface tension of the Cu-Al system melts were established. It was shown that Cu-Al melts wet the substrates at 1000 K and more. We revealed the features of temperature dependences of the wetting angles.