INFLUENCE OF DEPOSITION TECHNOLOGICAL PARAMETERS ON THE STRUCTURE AND PHRASE COMPOSITION OF YTTRIUM ALUMINATES-BASED COATINGS

Abstract

Today, in connection with the growing requirements of power engineering and the aerospace industry, the urgent task of the industry is to search for new high-temperature materials with high specific strength characteristics. In addition, the growing demands on the fuel efficiency of power units are forcing not only to use the materials with a low specific mass, but also to increase the operating temperature in turbines, which, in turn, requires the use of high-temperature and heat-resistant materials. New cobalt and nickel-based alloys, metal-matrix composites with a molybdenum matrix reinforced with ceramic fibers and new alloys based on the Mo-Si-B system meet high requirements for high-temperature  resistance. However, due to the vulnerability of the molybdenum matrix to oxidation and the limited oxidation resistance of nickel and cobalt alloys, to ensure the heat resistance of the product, it is necessary to use protective coatings that protect these alloys from corrosion in the aggressive environment of an aircraft engine turbine. Currently, there is an active search for new high-temperature ceramic systems capable of replacing MCrAlY coatings and yttria-stabilized zirconia, which have exhausted their physical capabilities. One of such systems is a group of Y-Al-O oxides, which demonstrate high oxidation resistance and stability in high-temperature environments. The paper presents a fundamentally new method for the formation of heat-resistant coatings based on the Y-Al-O system on a molybdenum substrate using the method of vacuum-arc deposition with plasma assistance and subsequent annealing in vacuum and study of the effect of technological modes of deposition on the phase composition of the coating. The resulting coatings were studied using X-ray diffraction analysis.