Sotnikov Y. Improvement of the composition of the gas-thermal sealing coatings of the turbine parts to enhance the efficiency of gas turbine engines.

The matter for scientific inquiry is the processes of formation and structurization of the gas-thermal sealing coatings of the hot gas path parts of the gas turbine engine. The subject of the research is the structural and phase transformations in the improved yttrium-containing sealing coatings of the gas turbine engine parts and the nature of the changes in their properties in high-temperature environment. The objective of the research was to solve the scientific and technical problem of developing the composition of the sealing coating for the parts of gas turbine engines that are exploited for a long time under the influence of an aggressive, warmed up gas flow at elevated temperatures. Methods of research. In order to solve the identified problems and obtain the basic results of the research, the following methods were applied: X-ray diffraction study was used to examine the phase transformations in the material; metallographic methods with the scanning electron and optical microscopy were exploited to analyze the transformations in the structure of the coating when applying it and during further operation; methods for the study of mechanical properties were used to evaluate the service reliability of the products; methods for the research of thermophysical properties were applied to forecast the behavior of the material under the influence of the temperature factor; methods for modeling the process of a labyrinth sealing use were applied to evaluate the impact of the coatings wear-our rate and increase of the radial clearances on fuel consumption and get recommendations on the choice of the optimal composition of the sealing coatings. The research was carried out at the Department of Physical Material Science, Zaporizhzhia National Technical University, in collaboration with Motor Sich JSC. Results of the study. The topical problem of developing the chemical composition of the sealing coating for the turbine with high service durability under the influence of a high-temperature gas flow was solved. By applying the modeling methods, it was found out that the usage of this coating enables to increase the efficiency of the engine due to the decrease of gas leakage while retaining the size of the radial clearances and reduce fuel consumption by 2,3 kg per hour, which results in the general reduction of the annual consumption of aviation fuel by 184 tons. The results of the study are implemented in the manufacturing process at Motor Sich JSC (Zaporizhzhia) and in the educational process at the Department of Physical Material Science, ZNTU.