Study of the Change in the Phase Composition of the Y–Al–O Coating System and its Structure during Vacuum Arc Deposition

Abstract

Recently the development and research of new heat-resistant coatings that improve the performance of parts in aggressive environments is becoming increasingly relevant. This is especially important in the production of gas turbine engine parts, gas pumping units and turbochargers of internal combustion engines. There is active research for compositions of metal and ceramic coatings capable of replacing the widely used MCrAlY composition, where M–Ni or Co, variations of which are known as SDP and VSDP alloys known for heat resistance and resistance to oxygen diffusion to the substrate. These compositions are characterized by high adhesive strength to heat-resistant alloys with various spraying technologies, therefore new heat-resistant coatings should not be inferior to them in adhesive strength. The research of structural and phase transformations during the deposition of coatings in a reaction gas environment seems very perspective. One of the most common methods of functional coating deposition is vacuum arc deposition in a reaction gas environment. This allows to achieve a high deposition rate, process controllability, good adhesion and ensure the content of necessary chemical compounds in the coating, depending on the reaction gas supplied to the chamber. This article investigates in situ phase transformations in the coating of the Y–Al–O system during vacuum arc deposition on stationary samples using synchrotron radiation and presents the results of an analysis of the structure and elemental composition. It is shown that in the case of deposition on stationary samples during in situ synchrotron radiation, a mixture of Y₂O₃ oxide, pure yttrium and aluminum is formed in the coating. The thickness of the formed coating is about 10 microns, ensuring continuity and a small number of defects.