Evaluation of the Tribotechnical Characteristics of Therma-Barrier Sealing Coatings under Critical Loads

Abstract

This article deals with the initial stage of a comprehensive multifactor study of the wear resistance of thermal-barrier sealing coatings in the turbine of a gas turbine engine (GTE) under critical loads without taking into account the effect of structural phase transformations that can occur in coating materials during engine start-up and the subsequent long exposure of the GTE parts to high temperatures of about 1150°C. In compliance with the requirements of the GOST 30 480–97 state standard, the process of wear intrinsic to the full-scale tribological conjugation was simulated to obtain frictional-wear characteristics such as the friction coefficient, wear rate, and friction work under preset conditions that were used for further analysis of the wear process and acquisition of the initial data for field trials. The results of the above tribotechnical tests allow us to draw some tentative conclusions on the effect of alloying the nickel-based sealing coatings by yttrium-containing alloying compositions on their behavior during the tribological interaction and propose coating compositions that can be recommended for the subsequent stages of the study of the durability of sealing coatings under high-temperature conditions accompanied by volumetric changes in products and coatings as a result of structural phase transformations in multicomponent coating compositions.