Ion-Plasma Spraying and Electron-Beam Treatment of Composite Cr-Al-Co-ZrO2-Y2O3 Coating on the Surface of Ni-Cr Alloy

Abstract

The blades of modern gas turbine engines are complex structures made of heat-resistant nickel alloys with a complex system of internal cavities. The article describes a method of strengthening samples of a heat-resistant Ni-Cr alloy by applying a composite coating (Cr-Al-Co + ZrO2-Y2O3). The alloy prototypes were fabricated by vacuum melting. An ion-plasma technology of a two-layer coating with an inner metal and an outer ceramic layer on the prepared surface of the heat-resistant alloy matrix was developed. The morphology and structure of the alloy prototypes and the investigated composite coating were studied by scanning electron spectroscopy. The total thickness of the two-layer wear-resistant coating was 17–18 μm. The thickness of the inner layer (Cr/Al/Co) is 10–11 μm and the thickness of the outer ceramic coating (ZrO2-Y2O3) is 6–7 μm. To improve the operational characteristics of the material, an electron-beam surface treatment was proposed. The research results showed a sevenfold increase in surface resistance compared with the initial state.