High-Temperature Oxidation Studies of Plasma-Sprayed NiCrAlY/TiO2 and NiCrAlY/Cr2O3/YSZ Cermet Composite Coatings on MDN-420 Special Steel Alloy

Autor: C. Durga Prasad, T. Nageswara Rao, M. R. Ramesh, G. Madhu Sudana Reddy, Gagan Shetty, Pradeep Patil
Rok vydání: 2021
Předmět:
Zdroj: Metallography, Microstructure, and Analysis. 10:642-651
ISSN: 2192-9270
2192-9262
DOI: 10.1007/s13632-021-00784-0
Popis: The plasma spray process was used to form 70%NiCrAlY + 30%TiO2 and 70%NiCrAlY + 25%Cr2O3 + 5%YSZ cermet coatings on MDN-420 special steel alloy . Cyclic oxidation testing was conducted on coated and uncoated specimens at 700°C under a static air environment. Thermogravimetric analysis was applied to establish the oxidation kinetics. X-ray diffraction (XRD), scanning electron microscopy (SEM)/energy-dispersive x-ray spectroscopy (EDS), and electron probe microanalysis (EPMA) techniques were used to analyze the oxidized products. The NiCrAlY + Cr2O3 + YSZ coating was found to be most resistive when compared with the NiCrAlY + TiO2 coating in the aggressive oxidation environment. Net weight loss was observed for bare MDN-420 alloy due to sputtering. The oxidation resistance of the coatings was due to formation of Cr2O3, NiCr2O4, NiO, and Al2O3 phases.
Databáze: OpenAIRE
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