Responsible parts of gas-turbine engines are made of nickel superalloys by the method of precise (precision) casting, also called investment casting. Removal of model compositions from shell molds is the most important stage of this technological process, which largely determines the quality of the finished casting. The article examines the features of the modern method of removing waxy model compositions, which is widely used in the domestic industry, using a boiler-autoclave in a medium of superheated water vapor.

The main types of currently used free-machining steels, including corrosion-resistance free-machining steels, are observed. The chemical composition of corrosion-resistant free-cutting steel has been developed. The influence of various quenching and tempering temperatures on the microstructure and properties of corrosion-resistant free-cutting steel has been investigated. The results on the machinability of steel with the selected chemical composition and its heat treatment mode, ensuring an increase in cutting speed and tool life, are presented.

The article addresses the problem of assessing the expected content of non-metallic inclusions and other defects in materials used for manufacturing rotary components of turbines and compressors for aircraft gas turbine engines. The importance of objective information on defects not detected by non-destructive testing methods for the reliable determination of the safe service life of the engine is highlighted. Various methods for collecting and processing information on the quantity and size of defects in the material are reviewed, with their advantages and disadvantages listed. The choice of research directions aimed at developing a methodology for quantitative assessment of defects in granulated alloys is reasoned.

The strain hardening propensity of nitrogen-containing corrosion-resistant steel 15Kh15N4AGM-Sh used for manufacturing thin-walled tubes for aviation applications was investigated. Based on the simplified Johnson–Cook model, strain hardening parameters A, B, and n, as well as the introduced hardening coefficient H_c, were calculated based on test results. It was determined that tempering at 500 °C provides maximum values of coefficient B (500 MPa) and exponent n (0,23), while tempering at 600 °C results in reduced strength properties (σ_0,2 = 1165 MPa) while maintaining sufficient ductility.

The basic components which are applying at creation of elastic adhesives for gluing of non-polar rubbers on the basis of natural rubber during vulcanization are considered. Information on some domestic developmed adhesive systems with characteristics is presented comparable to the international adhesive system Hemosil 211/411. The results of researches of adhesive joints of non-polar rubber on the basis of natural rubber with metal, executed with use of experimental adhesive system « adhesive ‒ adhesive intermediate layer» in initial condition and after influence of the factors simulating operational are provided.

Use of industrial electric furnaces with operating temperatures of 1650–1800 °C required development of highly refractory materials with good thermal insulation properties. In industries where furnace temperatures exceed 1500 °C, mullite-corundum refractory materials containing crystalline fibers of high-alumina corundum and mullite are applied. The purpose of this work is to study the phase transformations and behavior of an experimental lining material produced by NRC «Kurchatov Institute» – VIAM under furnace operating conditions and to compare its properties with a similar imported material.

This paper presents studies on the change in the durability of carbon fiber reinforced plastic during moisture sorption. For this purpose, at different stages of material moistening and in the dried state of it, short beam shear tests at loading rates differing by 3–4 orders of magnitude, cyclic tension-compression tests with increasing loading amplitude and a dynamic mechanical analysis were carried out. The study shows that the strength properties and the glass transition temperature of the carbon fiber reinforced polymer with different moisture content conform to the temperature-humidity analogy and ramp-down with the increase of moisture content.

The article investigates the effect of the nature and concentration of wetting and dispersing additives on the rheological properties and stability of model ceramic slurries based on (meth)acrylate resin and aluminum oxide. The influence of the mass fraction of aluminum oxide on the rheology and stability of ceramic slurries is presented. Stable highly filled ceramic slurries with an alumina particle content of 51,5; 55,4 and 60,0 vol. % and low viscosity 2,16; 4,09 and 6,06 Pa∙s at a shear rate of 30 s^–1 at a temperature of 25 °C were obtained.

This article examines the classification and influence of fillers on the properties of PDC (polymer-derived ceramics) materials, along with their functional characteristics. The study analyzes chemical resistance, thermal, dielectric, magnetic, optical and mechanical properties of PDC materials. Particular attention is given to methods for minimizing shrinkage and porosity during pyrolysis, as well as potential applications of PDC materials in high-tech industries.

This article presents a review of international scientific and technical literature on galvanic protective coatings used at temperatures up to 600 °C. According to the review, over 60 % of the research is devoted to the production of composite coatings based on nickel and its alloys. The most common alloying systems for composite electrolytic coatings based on nickel are identified. It is noted that the production of nickel-cobalt composites by electrodeposition is a promising approach, but it is primarily limited to laboratory experiments, and scaling up for industrial mass production remains a significant obstacle.

The article presents the patterns of friction of silicon nitride from load and sliding speed paired with materials of different types. Materials of various classes, which are most often used in the mechanisms of friction units, are selected as counterbells. In the process of friction of various materials with silicon nitride, oxide films, surface activity, and activation energy of the interplane shear of planes are actively involved. Polymer and self-lubricating materials showed the lowest coefficient of friction with silicon nitride. 

The study considers possible destruction causes of the PZlM-type solder wire made of gold-copper alloys used for soldering and assembling of components in electrovacuum devices. The possible causes of wire defects are impurities of rhodium and ruthenium, entering into the solder wire due to improper control of the chemical composition of the source materials, caused by the imperfection of the current regulatory documentation for solders and their components. It is proposed to carry out the output control of manufactured PZlM-type solders after at least 10 days, required for recrystallization and alignement of the material after preliminary annealing.

A special feature of non-destructive testing using X-ray computed tomography (XCT) of medium-sized aluminum alloy housing parts is that a tomogram is obtained simultaneously for two parts, CAD models of products were embedded in images for decoding tomographic images and sorting out control objects. Defect coordinates relative to the clean outline of the CAD model were used to determine their acceptability. Since X-ray computed tomography (XCT) is not feasible, porosity score assessment is selectively performed using traditional X-ray methods. 

This study demonstrates the potential of energy-sensitive computed tomography for studying the sorption of heavy elements in sorbents and filter system models. The experimental results demonstrated the feasibility of simultaneously visualizing and identifying multiple chemical elements in a filter system. The proposed method is a non-destructive testing method and can be used to protect the environment from emissions containing heavy elements.

The taxonomic identification of mycelial fungal strains from the collection of the NRC «Kurchatov Institute» – VIAM was carried out using methods of genome-wide taxonomy. The taxonomic classification was performed at the Kurchatov Genomic Center using two approaches: genomic signature analysis and a full-fledged phylogenetic analysis of 255 marker single-copy eukaryotic genes. This article presents data from phylogenetic analysis of strains based on sequences of universal eukaryotic marker genes of the following fungi: order Glomerellales, genus Colletotrichum; the family Pleosporaceae; the genera Curvularia and Alternaria, the genus Aspergillus, and representatives of new orders of the class Sordariomycetes.

An analysis of the precise chemical composition and spatial distribution of chemical components in thin DyPrCoFeB conductors was conducted. The magnetic stray field near the polished end of the microwire was studied, and the features of its surface structure were determined. The microhardness (9,56 GPa) and modulus of elasticity (159 GPa) of polished DyPrCoFeB samples were measured. The maximum allowable load limit (~6 N) was determined; exceeding this limit causes irreversible plastic deformation of the microwires.

Heat-resistant alloys and steels

Forostovich T.L., Narsky A.R., Bityutskaya O.N. Removal of model compositions from shell molds using a boiler autoclave

Leonov A.V., Voznesenskaya N.M., Ulyanov E.I., Yakusheva N.A., Eliseev E.A. Investigation of a new corrosion-resistant free-machining steel

Gerasimov D.M., Krasnov I.S., Dalin M.A. Problems of quantitative assessment of defectiveness in granulated nickel-base superalloys

Sevalnev G.S., Dulnev K.V., Oblivantsev K.D. Study of strain hardening propensity as a function of processing temperature in thin-walled tubes produced from nitrogen-containing corrosion-resistant steel

Polymer materials

Manzhosova Е.N., Lukina N.F., Isayev А.Yu., Smirnov О.I. Approaches to creation of adhesives for gluing of non-polar rubbers based on natural rubber with metals in curing process

Composite materials

Babashov V.G., Maksimov V.G., Butakov V.V., Varrik N.M. Investigation of phase transformations and formation of crystalline phases in materials for lining high-temperature electric furnaces

Startsev O.V., Dvirnaya E.V., Kornienko G.V., Petrov M.G. The effect of moisture on the strength and durability of carbon fiber reinforced plastic

Butuzov A.V., Lebedeva Yu.E., Semina A.V., Serkova E.A., Lonskii S.L. Influence of the nature and concentration of the wetting-dispersing additive on the rheological properties and stability of highly filled ceramic slurries based on aluminum oxide

Parashchenko N.M., Tupikov A.S. Review of polymer-derived ceramics (PDC). Part 2. Properties of ceramics and the effect of fillers on them

Protective and functional

coatings

Vasiliev A.S., Vdovin A.I., Zakirova L.I., Koltsova M.А. Modern trends in the development of galvanic protective coating that can operate at temperatures up to 600 °С

Material tests

Sevostyanov N.V., Pastukh E.S., Shchegoleva N.E., Vershinin D.I., Vikulin V.V. Patterns of dry friction of Si₃N₄ with different types of materials

Galkin V.I., Golovkin P.A., Dvoretskov R.M., Galkin E.V. About possible destruction causes of vacuum melted PZlM-typesolders

Demidov A.A., Trapeznikov A.V., Kosarina E.I., Osiyanenko N.V. Features of non-destructive testing of silumin castings by X-ray computed tomography

Shashurin D.A., Sidorov D.V., Suslova E.V., Martynova N.A., Chelkov G.A. Visualization of adsorption of heavy elements in industrial filters by energy-sensitive computed tomography

Krivushina A.A., Startsev V.O. Identification of the mycelial fungi collection of NRC «Kurchatov Institute» – VIAM by molecular genetic methods. Part 1

Dvoretskaya E.V., Kolmakov A.O., Buzenkov A.V., Potapov M.V., Piskorsky V.P., Morgunov R.B. Microhardness of rare earth microwires