Key Engineering Materials Vol. 685

Abstract: The article reports the results of the experiment studied the effect of radiation spectral content (considering its equal intensity in terms of photosynthetically active radiation) on the growth and development of Boets greenhouse tomato breed. We have shown that the effective development of model subjects requires the adaptation of radiation spectral content depending on the growth period and type of a plant, unlike the illumination level. The obtained results demonstrate the necessity of creating an adaptive irradiation unit.

Abstract: It is shown that combination of strain effects leads to possessing the ultra-fine grain structure in carbon wire. The continuous method of wire deformation nanostructuring was developed on the basis of simultaneous applying of tension deformation by drawing, bending deformation when going through the system of rolls and torsional deformation on a continuously moving wire. One of the main advantages of the developed method is that various hardware devices and tools already applied for steel wire production can be used to implement this method thus simplifying its introduction to the current industrial equipment. The efficiency estimation of the developed continuous method of deformation nanostructuring was carried out using carbon wire with different carbon content. It is shown that the mechanical properties of the wire after combination of different kinds of strain can vary over a wide range. This method makes it possible to choose such modes of strain effect, which can provide the necessary combination of strength and ductile properties of carbon wire depending on its further processing modes and application.

Abstract: The composite wire compound calculation methods were considered, factoring stoichiometric ratio values of the elements of the intermetallic γ'-Ni₃Al, draft, elongation and compaction of the filling’s components as well as the values of alloy transfer effervescive. It is found that during argon-arc surfacing the components of the composite wire’s filling and coating are melting uniformly at the welding current density from 30 to 50 A/mm². The correlation was established between the composition, the construction of the composite wire for arc welding and surfacing and the structure of Ni₃Al based deposited metal. It is shown that the developed composite wire provides the deposited metal with the structure of nickel aluminide economically alloyed with wolfram, molybdenum, tantalum and chrome.

Abstract: The results of studies of fabrication of porous titanium boride TiB by self-propagating high-temperature synthesis (SHS) using ordinary (not granular) and granular initial powder charge titanium-boron are presented. The influence of the amount of titanium in the charge, the granule size and the pressure of compaction of the charge on the structure, porosity, phase composition and compression strength of the resulting porous materials is described. The results of studies were obtained with the use of the scanning electron microscope, diffractometer and universal testing machine.

Abstract: A wear-resistant composite coating process with electroslag surfacing using a current-supplying solidification mould was developed. The structure and properties of coatings from flux-cored wire deposited alloys with refractory micro-particles of titanium diboride, TiB₂, and nano-sized particles of titanium carbonitride, TiCN, were studied. Special features of the elasto-plastic deformation of composite alloys’constituents were studied with sclerometry.

Abstract: Efficient two-step technique of tungsten and molybdenum disulfides obtaining from metal nanopowders produced by EEW and elementary sulphur is described. Tungsten and molybdenum nanopowders surface area dependence on wire length is studied. Features of metal and sulphur combustion process are discussed. It is determined sulphur excess in reagents 15 wt.% results in mono-phase metal disulfide formation with small free sulphur concentration in reaction products.

Abstract: The microstructure of aluminum nanopowder combustion crystalline products in air and the influence of a constant magnetic field (with induction of 0.3 T) on their structures have been studied. It was revealed that in the combustion products of free-poured aluminum nanopowder two-level whiskers are present. Hexagonal single crystals are formed by combustion in air in a homogeneous magnetic field, and in case of inhomogeneous magnetic field (with induction of 0.3 T) faceted elongated crystals of micron size are generated. The crystallites of such structure are formed due to the mass transfer of the combustion products in the direction of thermal flows. Ordered six-sided crystal structures are formed by overcooling the oxidation products by the action of magnetic field and by increasing the mobility of their structural units in recrystallization thermal wave. According to electron- microscope investigation the formation of the faceted crystals is possible with optimal sizes of combustion product particles.

Abstract: The intermediate and final combustion products of pressed aluminum nanopowder are studied. It is found that the main combustion product is aluminum nitride. In the intermediate stages of combustion, aluminum oxide (γ-Al₂O₃) and oxynitride (Al₅O₆N) are the first to form on the sample surface, and aluminum nitride is formed next. The use of sliding (incident at a small angle to the surface) synchrotron radiation made it possible to determine with high accuracy (in time) the sequence of stages of formation of crystalline products during combustion of the aluminum nanopowder.

Abstract: The changes of the phase composition, structure and physicomechanical properties of Ti‑40 mas % Nb after severe plastic deformation are investigated in this paper. By the methods of microstructural, X-ray diffraction analysis and scanning electron microscopy it is determined that phase and structural transformations occur simultaneously in the alloy after severe plastic deformation. The martensitic structure formed after tempering disappears. The inverse α'' → β transformation occurs. The structure consisting of oriented refined grains is formed. The alloy is hardened due to the cold working. The Young modulus is equal to 79 GPa and it is less than that of initial alloy and close to the value obtained after tempering. It is possible that Young modulus is reduced by additional annealing.

Abstract: This paper reports about the method of modified nanomaterials. The aluminum oxyhydroxide was modified by manganese ions (II) during the synthesis. It was shown that modified aluminum oxyhydroxide has new function properties such as catalytic properties. It was shown that the modified aluminum oxyhydroxide with the high concentration of manganese ions (II) could be used in the reaction of the oxidation of methane.