According to the results of tribotechnical tests of coatings made of KNA-82 alloy ligatures with the addition of yttrium of 0.1%, 0.3%, 0.5%, data were obtained that allowed us to establish the nature of changes in the dynamic coefficient of friction over the test period and numerous values of the energy intensity of material wear. The evaluation of coatings formed by the gas-flame and ion-plasma method was based on the following premise. The maximum resistance to mechanical fracture is determined by the manifestation of a constant minimum value of the dynamic coefficient of friction. This serves as an indicator of reduced friction force before reaching the fatigue limit. Another key factor is the number of separated particles produced per unit of integral work during the friction process. These evaluation parameters are lined up in a row by the number of points from 1 to 4. The maximum score corresponds to the maximum resistance, i.e., a lower value of the energy intensity of material wear and the minimum value of the stable friction coefficient. It has been determined that the same coincidence of these parameters according to the scores is almost at all stages of testing (I-III) was the coating formed by the gas-flame method with a yttrium concentration of 0.3%-0.5%. The exception was the coating formed by the ion-plasma method with a yttrium concentration of 0.1% at the fourth stage of testing.

В роботі представленні випробування жароміцних ущільнювальних ітрійвмісних покриттів на високотемпературну газоерозійну стійкість. Дослідження включає в себе візуалізацію та характеристику геометрії профілю доріжок врізання, оцінку зміни кольору поверхонь та внутрішньої структури порошкових покриттів. Отримані результати вказують на відсутність значущих геометричних змін на поверхнях, а також свідчать про можливе утворення оксидів під впливом високої температури. Зауважено деформування структури порошкових покриттів, накопичення мікронапружень та ущільнення об'ємної структури. Додатково, в статті розглянуто вплив концентрації ітрію на мікрозношування, зазначено приріст маси покриттів. Встановлено, що присутність ітрію в складі ущільнювального покриття впливає на швидкість приросту маси в залежності від концентрації та способу нанесення. Отримані результати відкривають перспективи подальших досліджень ущільнювальних покриттів, які експлуатуються в умовах гарячого тракту ГТД.

Наведено результати випробувань вихідних структур жаростійких ущільнювальних покриттів з вмістом ітрію 0,1%; 0,3%; 0,5% у складі лігатур КНА-82, які попередньо були сформовані у газополум’яний та іоноплазмовий спосіб на малогабаритних дослідних зразках. Оцінені зміни фізичного стану зразків за приростом маси при моделюванні статичного високотемпературного навантаження шляхом витримки у обмеженому просторі електричної печі при температурі 1100 оС. Визначено, що приріст маси зразків із збільшенням вмісту ітрію змінюється за лінійною залежністю та суттєво відрізняється від характеру приросту маси за умовами моделювання динамічного навантаження у середовищі палаючої газової ізооктан-пропан-бутанові суміші при температурі 950-1020 ℃.

The paper presents the results of a study of linear wear of gas-flame and ion-plasma coatings of KNA-82 seals with an yttrium content of 0.5%, used in gas turbine engine assemblies, during physical modeling of their thermomechanical loading on small-sized samples. Tribotechnical tests were carried out in four stages, simulating the operating conditions of real gas turbine engines—from the first start-up with running-in of the coating cut-in areas to reaching a steady state with their service properties formed. The surface of the coatings was in contact with the ridges of triangular-shaped plates without heating (20 °C), at average heating (350–470 °C), after holding the samples at 1100 °C and average heating of 410–460 °C, and after grinding off the worn layer that had worn out after holding the samples at 1100 °C at average heating of 320–440 °C. Trends in the change in the linear ear of coatings and the formation of friction tracks caused by the uneven manifestation of the physical and mechanical properties of coatings, which are unevenly distributed throughout their body, were determined. It was found that both coatings tend to stabilize the wear process at certain mechanical pressures in the friction contact zone and only in the temperature range from 20 °C to 400 °C. These pressures range from 4 MPa to 6.7 MPa for gas-flame coatings and from 3 MPa to 4.2 MPa for ion-plasma coatings. It has been determined that within the depth range of 30–100 μm, the wear resistance (as assessed by linear wear) of ion-plasma coatings is higher than that of gas-flame coatings. This predetermines the fact that in the event of a catastrophic collision between the coatings and a blade, the geometry of the damage to the surface of the gas-flame coating will be greater than that of the ion-plasma coating. In the event of damage exceeding 75–100 μm in depth, both coatings become inoperable, since their wear characteristics are no longer maintained. This is indicated by a rapid decrease in their wear resistance under step loading. Moreover, the gas-flame coating is more prone to catastrophic failure than the ion-plasma coating.

The purpose is to establish dependencies between chemical and phase composition in the Ni-Al-Cr-Co-W-Mo-Ti-Nb-Ce-Zr-B-La system; obtain dependencies between the mismatch of crystal lattices of the strengthening phase and matrix; obtain dependencies between phase composition and mechanical properties to increase the service life of hot-tract parts.The methodology for obtaining the dependencies involved simulating the thermodynamic processes of phase formation, where the elements were changed step by step using the CALPHAD thermodynamic modelling method. Predictive calculations were performed based on the initial chemical composition of the VZhL-12 alloy, which determined the most probable phases and their corresponding chemical compositions. The phase composition was experimentally determined using a REM-106I scanning electron microscope with an energy-dispersive X-ray spectral microanalysis system. The method was employed to investigate the morphology and chemical composition of the precipitated phases within the alloy structure.The influence of individual alloying elements on phase stability has been established: aluminium promotes the formation of the γ′-phase, reaching its content of up to 89% at 7.6% Al, but when in excess, it causes the formation of brittle TСР phases, which impair ductility; titanium also increases the content of the γ′-phase, but when the content is above 6.4%, it leads to the formation of lamellar TСP phases (for example, the η-phase), which negatively affect the mechanical properties; cobalt and chromium increase their concentration in the strengthening phase, promoting its thermal stability. Molybdenum and tungsten do not directly participate in the formation of the γ′-phase but increase its heat resistance. The effect of temperature on the lattice parameters of the γ and γ′-phases is shown. The minimum mismatch of the lattice parameters (-0.4%) is observed at 700-800C, corresponding to optimal values of strength, ductility, and creep resistance. Experimental testing on the industrial single-crystal alloy VZhL-12 yielded good agreement between the calculated and actual data.The established patterns of alloying, phase transformations, and thermomechanical properties can serve as the basis for creating new generations of materials capable of operating under extremely high temperatures and loads. However, the disadvantages of this method include sensitivity to the initial data, the ability to analyse materials only in a stable state, and the reliability of thermodynamic databases (which have recently improved significantly). Future studies are planned to study the behaviour of secondary phases and the influence of rare earth elements in the system.The obtained relationships between alloying, phase transformations and thermomechanical properties can be used to create new generations of materials. They enable the determination of properties of new alloys without testing, significantly reducing research costs. The work will also be beneficial in refining the existing chemical compositions of alloys.The work is intended for researchers and engineers in the field of high-temperature materials (superalloys).