Gas turbine engine parts are made of nickel superalloys by die casting. One of the most important technological stages of this process, which largely determines the quality of the finished casting, is the removal of model masses from shell molds. The review examines the advantages and disadvantages of various methods of removing model compounds, as well as the main trends of domestic scientific research studies aimed at intensifying the process, reducing the possibility of cracks formation in molds and casting defects.

The article presents the results of a comparative study of the lattice parameters of the γ- and γ'-phases, the γ/γ'-misfit, γ'-solvus temperature, interfacial energy at the γ/γ' boundary and the antiphase boundary energy of single-crystal superalloys of the third to fifth generation. The focus was made on the dependence of these characteristics on the temperature and composition of the alloys. The calculations were carried out using thermodynamic modeling. It was found that the VZhM8 alloy has the highest values of misfit and γ'-solvus temperature; the VZhM4 alloy has the lowest interfacial energy at the γ/γ' boundary; the VZhM1 alloy has the highest antiphase boundary energy.

The article presents the results of a study of deformation welding processes of blanks made of EP718-ID alloy. Before upsetting, the blanks were soldered to protect the mating surfaces from oxidation and to improve the quality of the weld. Soldering was performed according to two methods: over the entire area of the mating surfaces and along the contour. After plastic deformation and heat treatment of the composite blanks, the weld on the stamping, pre-soldered along the contour of the mating surfaces, was destroyed after cooling. The welded joint on the stamping with soldering over the entire area remained inseparable.

A nickel-based brazing metal designated VPr56 was developed for high-temperature diffusion brazing of bimetallic blisk-type components made from heat-resistant nickel alloys EP975 (disk) and VKNA-25 (blade). The study examined the influence of alloying elements (Ti, Nb, B) on the brazing metal’s key processing characteristics: melting temperature, wettability, joint uniformity, and susceptibility to erosion of the base metal. Experimental design and regression analysis were applied to optimize the composition. It was shown that VPr56 meets the requirements for joints of gas turbine engines (GTE) joints.

In cast blades with an equiaxed structure, one of the key defects is shrinkage porosity, which acts as a stress concentrator and reduces both the material properties and the reliability of the blades. This defect is particularly pronounced in large-sized gas-turbine units and engines (GTU and GTE) blades, where conventional processing techniques fail to provide sufficient compensation for shrinkage during solidification. The first part of this article reviews the fundamental principles of existing theories on casting feeding. 

This study demonstrates the effect of annealing temperature on crystallite size, lattice parameters, and the degree of crystallinity of polyetherketoneketone (PEKK), containing carbon fibers. The particle sizes of the PEKK and carbon fibers were determined using optical and electron microscopy. Temperature dependences of the thermoplastic's degree of crystallinity, calculated using X-ray diffraction analysis, were plotted. The mechanism of isothermal crystallization of PEKK was studied, and the effect of polymer crystallinity on fracture microstructure was demonstrated.

The present work presents results of a study of gel polymer electrolytes based on polyvinyl alcohol, propylene glycol and LiTFSI salt. Using methods of IR spectroscopy, differential scanning calorimetry, synchronous thermal analysis and impedance spectroscopy, the influence of composition on the chemical structure, thermal properties, and ionic conductivity of the materials was examined. The increase in the LiTFSI content was found to lead to a significant increase in electrical conductivity – up to 25,96·10^–2 mS/cm at 343 K. Produced electrolytes demonstrate  high thermal stability and conductivity, which make them promising materials for application in solid-state power sources.

Using X-ray microdiffraction and microfluorescence methods, as well as electronography methods, the processes of structure formation in oxide monofilaments under the influence of temperature were studied. It was shown that the main phase of the studied samples is mullite. Research shows that all samples demonstrate the uniform phase composition during the monofilament length. The investigation shows pronounced grain structure with elongated crystallites, that have the mullite habitus. The grains demonstrate homogeneous distribution.

This review describes in detail the main methods of additive manufacturing (FDM, CJP, SLA, DLP), which make it possible to obtain three-dimensional structures with complex architecture (scaffolds) based on hydroxyapatite. The analysis of scientific information in the field of 3D printing of ceramics based on hydroxyappatite with subsequent application in regenerative medicine is carried out. The relevance of research in the field of obtaining biomedical products based on hydroxyapatite using additive technologies has been assessed.

The use of synthesized wollastonite (the main component being β-wollastonite) based on zeolite siliceous rock enables the production of epoxy compositions with high tribotechnical properties, hardness, wear resistance and adhesive strength to steel. Calcium silicate from zeolite-containing siliceous rock increases the chemical and thermal resistance of epoxy materials as well as their resistance to UV radiation, making it a promising material for use in the aviation industry.

The structure and physical and mechanical properties of a silicon carbide–based composite material reinforced with metallic fibers were studied. The optimal content of the reinforcing phase was determined, and the fiber surface was modified to improve adhesion to the matrix. Impact toughness, three-point bending strength, and the coefficient of linear thermal expansion were measured. It was found that fiber reinforcement contributes to the redistribution of internal stresses, leading to improved resistance to impact and bending loads. A correlation was revealed between the strength characteristics and the amount  of the reinforcement.

Vacuum annealing of the initially amorphous microwire with the (PrDy)–(CoFe)–B composition leads to the formation of a polycrystalline structure containing a magnetically hard tetragonal phase (PrDy)₂–(CoFe)₁₄–B₁ and a magnetically soft cubic Fe phase. This results in a significant broadening of the magnetic hysteresis loop and the disappearance of domains. Local laser irradiation induces local surface recovery of the amorphous structure along a predetermined path of the laser beam. In the irradiated zone, the domain structure is restored.

This article investigates the influence of process parameters, such as process temperature, aluminide coating application time, and the vacuum annealing temperature of the formed coating. At high temperatures uniform aluminide coating layer forms across the entire specimen surface. This finding opens up opportunities for applying these coatings to high-tech components with complex external and internal geometries manufactured via additive manufacturing. Such an approach will ultimately enhance the efficiency and reliability of modern gas turbine engines.

A method for electrochemical formation of inverse opals based on ZnO and ZnO(Al) using colloidal crystals as a template has been developed. The dependence of the phase composition and microstructure of inverse opals on the conditions of a two-stage synthesis, involving electrochemically induced deposition and subsequent annealing, were studied. Annealing resulted in the formation of single-phase aluminum-doped zinc oxide with a given inverse opal structure. The photoluminescence and photonic properties of inverse opals based on ZnO(Al) were studied.

The article presents an analysis of the strength and crack resistance of structures, in particular an L-shaped panel, using the finite element method. A methodology for estimating the limiting stress states of finite elements that determine the direction of crack growth based on criteria of linear elastic fracture mechanics is considered. Numerical simulation of an L-shaped panel under the influence of vertical load is carried out. The modeling included the discretization of the structure using the finite element method, the formation of stiffness matrices, and the study of limit states. The simulation results are in good agreement with experimental data for concrete structures.