REVISITING THE ECOTOXICITY AND EFFICIENCY OF DIFFERENT CLASSES OF INDUSTRIAL NONIONIC SURFACES USED FOR CLEANING METAL SURFACES IN THE PROCESS OF CAPILLARY CONTROL OF DETAILS OF THE AVIATION TECHNOLOGY (review)

A review of modern classes of nonionic surfactants used for cleaning metal surfaces is carried out. The following aspects are considered: efficiency of cleaning metal surfaces, ecotoxicity, biodegradability, impact on human health. The most promising class of surfactants – alkyl polyglycosides (APG) – for cleaning metal surfaces, including in the process of capillary control, has been determined. It is noted that APGs have shown high efficiency in removing even such contaminants as denatured protein and burnt corn starch from metal surfaces. In addition, APGs have the highest emulsifying ability among industrial surfactants, which effectively affects the reduction in surfactant consumption when cleaning the surfaces.

STUDIES OF THERMAL SHOCK RESISTANCE OF AN ANTI-OXIDATION COATING FOR A MULTI-LAYERED CERAMIC COMPOSITE

The article covers the performance of thermal shock resistance experiments of a ceramic composite with two types of anti-oxidation coatings. A thermal shock burner rig was used to carry out the experiments similar to those expected in a combustor of a turbojet engine. SEM and х-ray diffraction analyses were used to examine the antioxidation coatings. It was deter-mined that the coating based on the refractory compounds possesses high thermal shock resistance when exposed to the fuel gas flow from a burner rig.

THE DEVELOPMENT OF AUTOMATED LAYING:FROM THE BEGINNING TO OUR DAYS (review) Part 3. Comparison of ATL and AFP technologies. Hybrid technology of ATL/AFP

Automated tape laying (ATL) has found application in the production of simple parts: wing skins and flaps, vertical and horizontal tail panels. For laying out, tapes with a width of 75; 150 and 300 mm are used. Automated fiber placement (AFP) is used to produce complex structures with great visuals: fuselage and other contour structures. For laying, bundles with a width of 3,2; 6,35 and 12,7 mm are used. Presents a comparison of ATL and AFP equipment, including robotic hybrids ATL/AFP-machines.

THE DEVELOPMENT OF THE NEW VZhM200 SUPERALLOY AND THE TECHNOLOGY OF ITS PRODUCTION FOR CASTING OF THE ADVANCED ENGINES’ BLADES BY THE DIRECTIONAL CRYSTALLIZATION

FSUE «VIAM» has developed a new nickel-based superalloy VZhM200 and its manufacturing technology for casting of turbine blades with directional (pillar-type) structure for advanced turbine engines. The advantages of the VZhM200 alloy over the DS200 Hf alloy are presented in the article. The quality of VZhM200 alloy produced by FSUE «VIAM» meets the DS200 Hf, MAR M200+Hf alloys produced by Cannon-Muskegon Corporation and HOWMET Ltd in chemical composition, content of harmful and non-metal impurities, gases and mechanical properties.

NIOBIUM REINFORCED BY α-Al2O3 FIBERS Part 1. Two-Component Compositions

The paper reviews the results of development of a new class of high-temperature composites based on niobium and various types of reinforcers continuous monocrystalline fibers (MCF) α-Al2O3, with TiN, Mo, W barrier coatings, and with controlled (Si, Ti) and uncontrolled (O, C) impurities. The analysis of Nb–Si, Nb–C, Nb–O binary diagrams and Nb–Si–Ti, Nb–Fe–Ti ternary diagrams was performed, on the basis of which the matrix compositions were selected. The basis for the preparation of composites was the powder method of mechanical alloying of the mixture preparing, followed by its pressing together with α-Al2O3 MCF by spark plasma sintering (SPS) and further preparation of experimental samples. An analysis of the interaction of fibers with a matrix was carried out, where the matrix was Nb or system on the basis of the above mentioned binary or ternary diagrams.

STRENGTHENING FEATURES AND AGING KINETICS OF HIGH-STRENGTH CAST ALUMINUM ALLOY AL4MS BASED ON Al–Si–Cu–Mg SYSTEM

Based on the conducted research, it has been found that quenching with hot isostatic pressure and step-by-step aging with consistently increasing temperatures of low-temperature aging (first stage) and high-temperature aging (second stage) provides high tensile strength for AL4MS copper silumin during cold box casting, increases the flow stress by 10%, and maintains high plasticity compared to the level of properties after single-stage aging.

INFLUENCE OF TIME-TEMPERATURE PARAMETERS OF LONG-DURATION EXPOSURE ON TRANSFORMATIONS IN STRUCTURAL STEELS (review)

Low-temperature nitriding of steels is usually carried out in the temperature range of development of reversible temper brittleness. The holding time at these temperatures significantly exceeds the holding time during normal tempering, which can negatively affect the properties of steel. The article considers theories that explain the processes occurring in steels in the temper brittleness temperature range. It may be concluded that views linking the embrittlement of steel with alloying elements such as nickel in its content are not confirmed by the experiments; at the same time ideas based on classical views about the diffusion of chemical elements explain the processes in steel better.

EXAMINATION OF THERMOPHYSICAL CHARACTERISTICS OF A HEAT-PROTECTIVE MATERIAL BASED ON FIBERGLASS DURING DESTRUCTION

When designing advanced samples of aviation and rocket and space technology, during the operation of which the temperature on the surface of the material can exceed the temperature of destruction, it is important to have an understanding of the values of thermophysical properties. The work investigates the thermophysical properties of fiberglass in the initial state and after the binder is burned out in a muffle furnace. The temperature dependences of thermal effects, heat capacity, thermal diffusivity and thermal conductivity were determined, density was measured, and thermogravimetric analysis was carried out. Using a stereomicroscope, the microstructure of the lateral cut of the samples was examined and its evolution was determined during the burning of the binder.

INFLUENCE OF MORPHOLOGY, PHASE COMPOSITION AND CONTENT OF ALUMINUM OXIDE PARTICLES ON RHEOLOGICAL PROPERTIES OF AQUEOUS SUSPENSIONS BASED ON THEM

This work investigated the chemical and phase composition of aluminum oxide powders obtained by various methods (alkoxide, codeposition, thermal and plasma-chemical). The physicomechanical, thermophysical and thermal properties of ceramic samples based on them have been determined. The effect of the nature of the aluminum oxide powder and the production process parameters on the sedimentation stability of aqueous suspensions based on them has been determined. The influence of the content of particles of aluminum oxide, buffer solution and rheological additives on the viscosity, sedimentation and aggregate stability of aqueous suspensions has been determined.

ALUMINUM ALLOYS WITH ADDITIONS OF Sc AND Zr IN ADDITIVE MANUFACTURING (review)

The article provides a review of scientific and technical literature in the field of development of alloys with additions of scandium and zirconium and their use for parts of additive manufacturing. The article describes the character of the influence of scandium and zirconium on the formation of a bimodal structure during synthesis. The factors influencing the formation of hot cracks in synthesized samples are given. The effect of compression on the density, size and ratio of the number of equiaxed and columnar crystallites in the structure, roughness and mechanical properties of synthesized alloys with additions of scandium and zirconium, including alloys with experimental compositions, is shown.