PROCESS OPTIMIZATION OF CORROSION AND EROSION RESISTANT OF THERMAL BARRIER COATINGS FOR INCONEL ALLOY — A REVIEW

Inconel alloys, nickel-based superalloys, are widely used in high-temperature applications due to their excellent fatigue strength, creep resistance, and superior corrosion resistance at both ambient and elevated temperatures. Various Thermal Barrier Coating (TBC) deposition techniques have been explored to enhance their performance. This review examines different coating methods, including Electron Beam Physical Vapor Deposition (EBPVD), Cathodic Plasma Electrolytic Deposition (CPED), thermal spraying, and laser cladding, assessing their impact on microstructure and corrosion resistance. EBPVD was used to develop cubic YSZ and graded Ni-YSZ nanocomposite coatings on Inconel 690, characterized using atomic force microscopy, XRD, X-ray photoelectron spectroscopy, and electron probe microanalysis, demonstrating improved corrosion resistance. CPED was employed to deposit ceramic Al 2 O 3 coatings on Inconel 738, with microstructural analysis revealing continuous spheroids enhancing coating integrity. Aluminide slurry coatings of varying thicknesses were thermally sprayed on Inconel 690 and heat-treated, showing notable microstructural variations based on coating thickness and composition. Laser Engineered Net Shaping (LENS) was used to deposit Ni-22Cr-10Al-1Y-based coatings on Inconel 625, where microstructural analysis detected gas voids and cracks. Plasma-sprayed NiCr–Cr 2 O 3 and Al 2 O 3 40%TiO 2 coatings on Inconel 617 were evaluated for high-temperature gas applications, demonstrating superior corrosion resistance at [Formula: see text]C. This review highlights key findings, challenges, and research gaps in optimizing TBCs for Inconel alloys, contributing to their enhanced durability in extreme environments.