Hot Corrosion Behavior of Cr2AlC MAX Phase Coating on Inconel 738LC Subjected to V2O5 + Na2SO4

In this research work, the in situ Cr2AlC MAX phase was coated on IN-738LC by utilizing the spark plasma sintering operation. The aim of this study was to investigate the hot corrosion behavior of a coating that has been exposed to a mixture of Na2SO4 and V2O5 salts at 900 °C. The XRD pattern indicated the formation of Cr2O3, α–Al2O3 and mixed oxide (Cr, Al)2O3, which suggested formation of Al2O3–Cr2O3 solid solution, on the all of the samples. After being exposed to the salts, plate-like, coral-like, and fractured plate-like morphologies were found with the corrosion products. When the hot corrosion time was increased to 30 h, the oxide layer thickness increased; however, after 40 h, the layer thickness decreased from 50 to 40 µm because of cracks in the sample and spallation of the oxide layer. This was shown by the FESEM images of the sample cross-sectional area.