Abstract
The article presents the results of investigation of tribological characteristics of gas-flame and ion-plasma sealing coatings of KNA-82 system with yttrium content of 0.3% used in gas turbine engine assemblies. The tests were carried out in four stages modelling different operating conditions: without heating (22°C), under medium heating (350°C), after the samples were aged at 1100°C and after repeated high-temperature loading. To evaluate the wear resistance of the coatings, linear wear, reduced wear and conditional linear wear were analysed as a function of temperature and pressure in the contact zone. It was found that both types of coatings show a tendency to stabilise the wear process under thermomechanical loading. It was found that at 1100°C the wear of ion-plasma coating is 10% lower than that of gas-flame coating under constant mechanical loading and 34% lower under step loading. A significant difference in the behaviour of the coatings was found: the gas-flame coating shows a hyperbolic decrease in the reduced wear with parallelism of the curves in the range of 350-1100°C, which indicates the stability of the wear mechanism, whereas the ion-plasma coating is characterised by instability of the wear mechanism with pressure and temperature changes