| Abstrakt: |
The results of studies of the initial structures of high temperature resistant sealing coatings with yttrium content of 0.1%, 0.3% and 0.5% in the composition of KNA-82 ligatures, which were previously formed by gas flame and ion plasma methods on small-sized prototypes, are presented. The changes in the physical state of the samples in terms of mass gain during the simulation of static high-temperature loading by holding them in a confined space of an electric furnace at a temperature of 1100 оC were evaluated. It is determined that the mass gain of samples with increasing yttrium content varies linearly and significantly differs from the nature of the mass gain under the conditions of modelling dynamic loading in a burning iso-octanepropane-butane gas mixture at a temperature of 950-1020 ℃. It is determined that the maximum mass increase for gas-flame coatings under static loading is 30-35% at the yttrium concentration of 0.3-0.5%. However, for ionoplasma coatings with the same yttrium concentration, the mass gain is almost 2 times less than that of gas flame coatings. Comparing the peculiarities of changes in the rate of increase in the mass of coatings under dynamic conditions of high-temperature loading, a graphical model of changes in the physical state of coatings was obtained, according to which the minimum amount of secondary compounds will occur at the gas-flame method of formation with a yttrium concentration of 0.1% to 0.47%, at the ion-plasma method of formation with a concentration of 0.25% to 0.35% (under conditions of a slight increase in oxygen in the interaction medium). It was determined that, without taking into account the time of structural-phase transformations and chemical reactions, the weight gain of coating materials under static loading is much greater than under dynamic loading. [ABSTRACT FROM AUTHOR] |
