Oxidation Performance of NiCoCrAlY Coatings Deposited by High Velocity Air Fuel for Thermal Barrier Applications

High Velocity Air Fuel (HVAF) is an advanced thermal spray technique developed to produce dense, low inflight particle oxidation, and oxidation-resistant coatings. These coatings are particularly important for thermal barrier coating (TBC) applications in the aerospace industry. HVAF has shown greater potential for producing dense bond coats with minimal in-flight particle oxidation, making it ideal for TBC systems. In this study, NiCoCrAlY coatings were deposited on nickel based superalloy substrates using both HVAF technique, and the oxidation performance was evaluated at an elevated temperature over varying thermal cycle. This approach provided insights into the oxidation mechanisms and kinetics as they evolved over time. Deposition parameters were thoroughly characterized using AccuraSpray diagnostics, while the microstructure and oxide formation were examined using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The oxidation results demonstrated that HVAF-deposited coatings exhibited superior oxidation resistance due to their dense microstructure and reduced oxide inclusions. These findings highlight the effectiveness of HVAF for producing high-performance bond coats for TBC applications, particularly in environments requiring long-term oxidation resistance.