FeZrN Films: Magnetic and Mechanical Properties Relative to the Phase-Structural State

The paper presents results of investigation of Fe65.3–100Zr34.7–0N7.5–0 films prepared by dc magnetron deposition on glass substrates and subsequent 1-hour annealing at temperatures of 300–600 °C. The influence of the chemical and phase compositions and structure of the films, which were studied by TEM, SEM, XRD, and GDOES, on their mechanical properties determined by nanoindentation and static magnetic properties measured by VSM method is analyzed. The studied films exhibit the hardness within a range of 14–21 GPa, low elastic modulus (the value can reach 156 Gpa), and an elastic recovery of 55–83%. It was shown that the films are strong ferromagnets with the high saturation induction Bs (up to 2.1 T) and low coercive field Hc (as low as 40 A/m). The correlations between the magnetic and mechanical properties, on one hand, and the chemical composition of the films, their phase, and structural states as well, on the other hand, are discussed.

Investigation of granulometric, chemical and phase compositions of hot‑dip galvanizing wastes

The article presents the waste generated during the production of hot‑dip galvanizing. The results of the study of the particle size distribution of zinc dust showed that its particle size distribution in the size range of particles ≤ 250 μm, the proportion of which is 87 wt.%, corresponds to the fractional composition of standard powder zinc. In ash, the number of particles up to 250 microns in size is approximately 35 wt.%. Studies of the chemical and phase composition of the hot‑dip galvanized waste – zinc dust made it possible to establish that the zinc content of the waste approximately corresponds to powder zinc (GOST 12601). The proportion of pure zinc in dust is 95 %. Chemical and phase analyzes of the ash have shown that it contains zinc oxides, pure zinc and zinc chlorides. Zinc chlorides, in turn, can be a supplier of chlorine ions in thermal diffusion galvanizing. In this regard, it is of interest to use ash in the composition of the powder composition as an activating and zinc‑containing component. The results of the analysis of the conducted studies of hot‑dip galvanizing wastes – zinc dust and soot show that they are promising for their use as components in saturating mixtures in the production of zinc coatings by chemical‑thermal treatment. This will reduce the cost of galvanized products and ensure the recycling of zinc into industrial circulation.

Mechanical Behavior of Bi-Layer and Dispersion Coatings Composed of Several Nanostructures on Ti Substrate

Three coatings suitable for biomedical applications, including the dispersion coating composed of multi-wall carbon nanotubes (MWCNTs), MWCNTs/TiO2 bi-layer coating, and MWCNTs-Cu dispersion coating, were fabricated by electrophoretic deposition (EPD) on Ti Grade II substrate. Optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and nanoindentation were applied to study topography, chemical, and phase composition, roughness, hardness, Young’s modulus, plastic, and elastic behavior. The results showed that the best mechanical properties in terms of biomedical application were achieved for the MWCNTs coating with titania outer layer. Nevertheless, both the addition of nanocopper and titania improved the mechanical resistance of the base MWCNTs coating. Compared to our previous experiments on Ti13Nb13Zr alloy, a general tendency is observed to form more homogenous coatings on pure metal than on the alloy, in which chemical and phase compositions are more complex.

Formation and Properties of Oxide Coatings with Immobilized Zeolites Obtained by Plasma Electrolytic Oxidation of Aluminum

In this paper, we employed plasma electrolytic oxidation (PEO) of aluminum in a water solution of sodium tungstate (Na2WO4∙2H2O) with the addition of the pure and Ce-loaded zeolites clinoptilolite and 13 X for the preparation of oxide coatings. The obtained coatings were characterized with respect to their morphologies and chemical and phase compositions using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, atomic force microscopy, and X-ray diffraction. The prepared coatings contained γ-alumina, WO3, and metallic tungsten. The surface morphologies of the obtained coatings strongly depended on the PEO processing time; the roughness of all coatings increased with PEO time, while porosity decreased with PEO processing time as a result of microdischarge coalescence and growth. All coatings contained elements originating from the substrate and from the electrolytes. Coatings containing zeolites with Ce showed higher photoactivity than those with immobilized pure zeolites. The highest photocatalytic activity levels were observed for coatings containing immobilized Ce-exchanged clinoptilolite processed for 10 min. It was observed that both clinoptilolite and 13X zeolites improved the features of the PEO coatings in a similar manner, making natural and abundant clinoptilolite an excellent candidate for various applications.

On the intermetallic nickel alloy for the manufacture of parts by equiaxial casting and additive technologies

The article presents the results of studies of compositions of intermetallic nickel alloy based on casting single-crystal rhenium containing VKNA-25 grade alloy for the manufacture of parts by the methods of additive technologies. It is shown that an increase in the carbon content, as well as carbide-forming elements, while observing the known conditions for the balance of chemical and phase compositions, made it possible to find the composition of the material for which the patent of the Russian Federation was obtained.

The Influence of Nanometals, Dispersed in the Electrophoretic Nanohydroxyapatite Coatings on the Ti13Zr13Nb Alloy, on Their Morphology and Mechanical Properties

In this work, nanohydroxyapatite coatings with nanosilver and nanocopper have been fabricated and studied. The presented results concern coatings with a chemical composition that has never been proposed before. The present research aims to characterize the effects of nanosilver and nanocopper, dispersed in nanohydroxyapatite coatings and deposited on a new, non-toxic Ti13Zr13Nb alloy, on the physical and mechanical properties of coatings. The coatings were obtained by a one-stage electrophoretic process. The surface topography, and the chemical and phase compositions of coatings were examined with scanning electron microscopy, atomic force microscopy, X-ray diffractometry, glow discharge optical emission spectroscopy, and energy-dispersive X-ray spectroscopy. The mechanical properties of coatings were determined by nanoindentation tests, while coatings adhesion was determined by nanoscratch tests. The results demonstrate that copper addition increases the hardness and adhesion. The presence of nanosilver has no significant influence on the adhesion of coatings.

Research of chromosilicated coatings on compact powder steels

Microstructures, chemical and phase compositions of diffusion chromosilicated coatings on powder steels 20, 45, У8 and У10 are investigated. The presence of Cr23C6 and Cr7C3 phases with up to 0,25 % Si is shown in these coatings. The distribution of diffusing chemical elements over the depth of the coating and at the interface with the matrix base is studied. Keywords: diffusion, coating, microstructure, chromosilication, powder steel, corrosion resistance [email protected]

Improving in cold resistance of castings made of 20GL type steels

The analysis of the literature data on the steels used for the manufacture of castings operating at negative temperatures and the technology of their manufacture is carried out. The effect of chemical and phase compositions on the strength and impact strength characteristics is revealed. The rational technology for manufacturing of these castings is considered. Methods for obtaining of high impact strength of castings made of 20GL type steels at –40...–60 °C temperatures are given. Modification, microalloying and rational modes of heat treatment are used as methods of rational control of the steels structure. The heat treatment technology of castings, which provides the necessary package of properties and reliable operation, is proposed.

Phase Composition of Silicon in the Krasnoslobodsky Deposit of the Tambov Region

The study of the chemical and phase compositions of tripoli from Krasnoslobodskoye deposit in the Tambov region was carried out using modern equipment. Using the X-ray fluorescence analysis, the main elemental composition of the rock under study was established, determined mainly by the compounds of Si, Al, Fe, K, Mg, Ca, Ti, P, S, Na. It is shown that the proportion of silicon dioxide in the sample under study exceeds its content in tripoli from many Russian deposits and neighboring countries. The X-ray phase analysis with subsequent interpretation of the diffraction pattern showed that tripoli contains minerals of amorphous opal, microcrystalline - and -cristobalites as structural forms of silica, as well as small amounts of quartz, illite and montmorillonite impurities.