Study of Y-Al-O system coating deposited on Inconel 718 alloy

Abstract

Today the requirements for aircraft gas turbine engines are constantly increasing, in particular, totheir fuel efficiency, noise level and weight. A key factor in meeting these requirements, in addition todesign solutions, are the materials used in the engine, especially in its hot part, which allow increasingthe operating temperature and efficiency of the engine. Currently, complexly alloyed nickel alloyswith a given structure are used in aircraft engine turbines; however, their ability to resist corrosion andfatigue failure is close to exhaustion and is limited by a temperature of ~1150 °C on the alloy surface.Therefore, the development of new alloys and coatings that can operate at higher temperatures inturbines of aircraft engines continues. This paper presents the results of studies of the structure andphase composition of heat-resistant coatings based on the Y-Al-O system deposited on the Inconel 718alloy, using scanning electron microscope, X-ray diffractometer and in situ imaging during heatingby a VEPP-3 synchrotron radiation source. A coating based on the Y-Al-O system was deposited onnickel alloy and molybdenum samples by cathode-arc deposition from two single-component yttriumand aluminum cathodes in a mixture of oxygen and argon. The results of the study of the phasecomposition showed that after deposition in the medium of reaction gases, the Y-Al-O coating hadan amorphous structure. Subsequent heating in air leads to the crystallization of the coating with theformation of Y-Al-O mixed oxides, which have a dense structure, the analysis of which was carriedout using a scanning electron microscope. Using synchrotron radiation, phase transformations in thecoating were studied when the sample was heated to 1300 °C and held for one hour in air.