Electron-Beam and Plasma Oxidation-Resistant and Thermal-Barrier Coatings Deposited on Turbine Blades Using Cast and Powder Ni (Co)CrAlY (Si) Alloys Produced by Electron Beam Melting III. Formation, Structure, and Chemical and Phase Composition of Thermal-Barrier Ni(Co)CrAlY/ZrO2–Y2O3 Coatings Produced by Physical Vapor Deposition in One Process Cycle

• Published in: Powder metallurgy and metal ceramics 2022-09, Vol.61 (5-6), p.328-336
• Main Authors: Grechanyuk, M.I., Grechanyuk, I.M., Yevterev, Y.N., Grechanyuk, V.G., Prikhna, T.O., Bagliuk, G.A., Hots, V.I., Khomenko, O.V., Dudnik, O.V., Matsenko, O.V.
• Format: Article
• Language: English
• Subjects: Barrier layers; Ceramics; Characterization and Evaluation of Materials; Chemical composition; Chemical vapor deposition; Chemistry and Materials Science; Composites; Crystallization; Diffusion barriers; Diffusion coating; Diffusion coatings; Diffusion layers; Electron beam melting; Energy consumption; Glass; Materials Science; Metallic Materials; Natural Materials; Oxidation; Oxidation resistance; Phase composition; Physical vapor deposition; Protective and Functional Powder Coatings; Substrates; Thermal barrier coatings; Thermal resistance; Turbine blades; Yttrium oxide; Zirconium dioxide
• ISSN: 1068-1302; 1573-9066
• DOI: 10.1007/s11106-022-00320-x

Physical and chemical vapor deposition methods are used to apply thermal-barrier coatings (TBCs) to turbine blades. Operations intended to form a diffusion barrier layer constitute an individual process. This increases the coating application time and, accordingly, increases the energy consumption in the production of turbines. In this research, the development of barrier layers at the interface between the substrate blade material and oxidation-resistant metallic layer and at the interface between the oxidation-resistant metallic layer and ceramic layer using a combination of deposition processes was examined. The structure and chemical and phase composition of TBCs at the metal/ceramic interface (NiCrAlY and CoCrAlY alloys/ZrO 2 –(6–8) wt.% Y 2 O 3 ceramics) deposited in one process cycle were studied. The study focused on the samples cut from blades made of the directionally crystallized ZhS26-VI alloy. The NiCrAlY and CoCrAlY alloys were used for coating the blades. The experiments were performed employing L2 and UE-159 units at the Ivchenko-Progres (Zaporizhzhia) and Eltechmash (Vinnytsia) enterprises. The formation of a diffusion barrier layer at the metal/ceramic interface was examined when the blades preheated to 900 ± 30°C were kept for some time above the ZrO 2 –(6–8) wt.% Y 2 O 3 ceramic material at 2600 ± ± 50°C. Depending on the holding time, the diffusion barrier layer that developed at the interface between the metallic and ceramic layers significantly differed in morphology and chemical composition from the main TBC layers. The chemical and phase composition of the diffusion barrier layer was determined versus TBC deposition conditions. The results of thermal cycle tests of the coated blades were used to develop coating deposition conditions to promote a diffusion barrier layer with optimal composition and structure.