The influence of various heat treatment modes of high nitrogen martensitic corrosion-resistant steel of grade 30H15AMF-ShPD (VNS78-ShPD) on the corrosion resistance of the steel in tough test conditions is considered. The effect of different quenching and tempering temperatures on the microstructure, hardness and corrosion properties of the steel is studied.

The change in electrical resistivity of austenitic nitrogen-containing steel VNS53-Sh has been studied depending on heat treatment in the temperature range of 200–1000 °C. Using the IACS standard resistivity measurement method, the relationship between electrical resistivity and structural-phase transformations has been established, including chromium nitride precipitation, formation of discontinuous decomposition zones, and recrystallization. Threshold values of electrical resistivity for non-destructive testing of the phase composition of the steel under production conditions have been determined.
 

A generalized dimensionless crack-resistance criterion $\Xi$ for nickel-based superalloys processed by selective laser melting is proposed – the ratio of the plastic relaxation functional to the damage accumulation functional, combining solidification cracking, strain-age cracking and grain-boundary embrittlement with the $\gamma'$ precipitation kinetics. Defect-free synthesis corresponds to $\Xi > \Xi_{\text{cr}}$ with $\Xi_{\text{cr}} = 1$. The criterion accounts for 94 % of the experimental crack density variance against 41–74 % for known criteria. The VZhS1 (adjusted $R^2 = 0{,}88$ for six fitted parameters) and VZhS3 alloys designed with it were synthesized crack-free.

Isothermal creep tests in the range from 850 to 950 °C yielded a matrix stress exponent n = 6,24 and an effective activation energy Q ≈ 613 kJ/mol, indicating that creep is governed by dislocation mechanisms with a dominant contribution of dislocation climb past coherent γ′ precipitates. For the alloys developed, Q exceeds the nickel self-diffusion energy by 329 kJ/mol, which corresponds to the level of cast IN738LC. In terms of stress-rupture strength the VZhS1 alloy surpasses IN939, whereas at 1000 °C the highly alloyed VZhS3 alloy (σ₁₀₀ ≈ 130 MPa) approaches cast VZhL12U (~140 MPa) and exceeds the superalloys currently used in additive manufacturing

The influence of different aging parameters on the structure and mechanical properties of maraging steel of 02Kh13N5K9M4 grade, obtained by selective laser melting was investigated from the initial state material without the use of quenching. In the course of the work, the chemical composition and content of impurities, technological characteristics of metal powder composition were determined, the percentage of gas pores and microstructure were examined, the mechanical properties of samples after aging were evaluated, as well as the values of indirect indicators, such as the amount of residual austenite and hardness, were determined.

The article presents the technology of production of rhenium-nickel alloying, intended for alloying of casting high-temperature nickel alloys. A detailed technological scheme of production of alloying from preparation of initial materials to the release of finished products is described. It is shown that preliminary vacuum annealing of rhenium powder provides sintering of particles and effective degassing. The developed modes of powder annealing and alloying in a vacuum arc furnace with a non-consumable electrode allow to minimize the gas content, ensure uniform distribution of components inside the ingot, and increase the yield of the metal. The developed alloying is successfully used in the manufacture of single-crystal heat-resistant nickel alloys.

This paper presents a comprehensive analysis of the influence of specimen size and strain rate on the Johnson–Cook model parameters for a high-entropy alloy of the NiCoCrWNbAlTiCrRe system. Tensile tests were performed on specimens with diameters of 3, 5, and 7 mm at strain rates from 0.25 to 10 mm/min. It was determined that specimen diameter significantly affects the model parameters: the strain hardening coefficient (B) varies from 660 MPa for Ø5 mm specimens to 915 MPa for Ø3 mm specimens, while the yield strength (A) ranges from 462 to 596 MPa.

The analysis of the scientific and technical literature data on the influence of iridium on the structural phase characteristics, phase stability, and high temperature long term strength creep of single crystal Re- and Re–Ru-containing nickel based superalloys (NBSAs) has been carried out. It is established that the addition of iridium to rhenium-containing NBSAs is more effective than the addition of ruthenium, has a stabilizing effect on γ- and γʹ-phases, delaying the formation of harmful TCP phases in the temperature range of 900–1100 °C. As a result, single crystal rhenium containing NBSAs alloyed with iridium have a longer high-temperature creep life than alloys with ruthenium.

Whiskers of refractory compounds have high thermomechanical properties. Due to their small size and defect-free structure, they have high strength and high elastic modulus, which makes them a valuable reinforcing filler for composite materials. This article discusses the main mechanisms of the aluminum oxide whiskers growth model and methods for their production. There is a growing interest in production technology of refractory compound whiskers. Mullite and alumina oxide whiskers will be in demand in the production of composite materials.

The study investigates the influence of sintering additive concentrations on sintering process, resulting microstructure, physical and mechanical properties of silicon nitride based ceramics. It has been established that increasing the concentration of additive complexes from 5 to 15 wt. % increases the average density and the level of physical and mechanical properties of Si₃N₄ based ceramics. During sintering, complete transformation of α-Si₃N₄ into β-Si₃N₄ is observed with formation of elongated crystals. The nature of sintering process and formed microstructure are largely depend on the composition and properties of the molten additives.

The choice of materials for friction units requires an integrated approach. Traditionally, steels, bronzes and cast irons have been used, but polymers, due to their low friction coefficient and low cost, have also shown their effectiveness. However, the polymer life is limited by high loads and harsh operating conditions. In this regard, the development of metal matrix composite materials, which have already proven themselves in industry, is relevant. This article analyzes researches on materials for bearing assemblies over the past 10 years.

This article examines the materials, properties, manufacturing technologies and applications of fiberglass pipes. There are presented main types of fiberglass pipe manufacturing technologies and the industries, in which they are applied. The article gives the main properties of fiberglass pipes, highlighting that porosity is the significant reason for reduced strength properties. Pores act as stress concentrators and reduce diffusion resistance. A winding method using vibration is proposed to reduce porosity.

The details of aviation engineering are characterized by cases of simultaneous influence of the corrosion environment and mechanical stresses which can arise at influence of permanent and alternating loads. The protective properties of systems of paint and varnish coatings, when testing for corrosion fatigue, and also to determination of adhesive durability of paint and varnish coatings at normal separation in initial condition and after cyclic tests for corrosion fatigue were studied. For tests, systems of coverings on the basis of disperse reinforced erosion-resistant enamels EP-5236 with different primers were selected in comparison with serial system of coverings on the basis of EP-140 enamel.

The final part of the series of articles is devoted to the assessment of toxicological risks, modern regulatory measures and the development of less dangerous paint and varnish coatings. Data on the toxicity of modern and promising paint compositions for ships is analyzed, and key dangerous components are identified. A microplastic pollution risk management plan is presented. Prospects of creating environmentally friendly coatings, including aqueous dispersions, biocide-free and hydrophobic antifouling coatings, and nanoparticle materials, are discussed.

In this work the impurities of 36 elements in tantalum by high-resolution glow discharge mass spectrometry (GDMS) were determined. The sample preparation for analysis is described. The corresponding equipment settings were selected to achieve maximum analytical signals from all target elements. Spectral interferences were eliminated by using high resolution. Relative sensitivity coefficients were calculated for all determined elements using X-ray fluorescence spectroscopy.

The article presents the functional scheme and external appearance of a microdensitometer, which can be used to obtain information about the granularity of an X-ray film and determine whether it belongs to a specific class regulated by GOST R ISO 11699-1–2023. The technological sequence of obtaining a sensitogram and an optical density matrix, as well as the procedure for its statistical processing and the calculating the granularity of an X-ray film is given. An experimental verification of the developed technology was carried out on a certified D5 Agfa radiographic film with a known value of its grain size and full compliance with the declared and experimentally obtained grain size was obtained.

The paper presents an automatic measurement of fatigue crack peak based on the analysis of image intensity on the sample surface, which detects local changes in the crack development area and takes into account general and local shifts on the sample surface. The fatigue tests results showed the possibility to determine the crack tip position correctly. The proposed method can be used in non-destructive testing systems and in testing aviation materials to improve the reliability of cyclic cracking assessment.

The research presents experimental results of long-term field climatic tests of structural fiberglass based on an epoxy binder used in the aviation industry in a tropical humid climate on Hainan Island (PRC). The change in relaxation behavior of materials after exposure to tropical humid climate conditions lasting for 5 years was investigated. A comparative analysis of the obtained data with the results after exposure in a moderately warm climate (Gelendzhik, Russian Federation) was carried out.