Cyclic Oxidation Properties of the Nanocrystalline AlCrFeCoNi High-Entropy Alloy Coatings Applied by the Atmospheric Plasma Spraying Technique

Coatings

Farzin Ghadami¹  Soheil Ghadami¹  Mohammad Amin Davoudabadi² 

[1] Department of Materials Engineering, Tarbiat Modares University, Tehran P.O. Box 14115-143, Iran;Department of Physics, Science and Research Branch, Islamic Azad University, Tehran P.O. Box 11365-4435, Iran;

关键词: AlCrFeCoNi high-entropy alloy coating;    APS deposition;    cyclic oxidation;   

DOI  :  10.3390/coatings12030372

来源: DOAJ

【 摘 要 】

Microcrystalline and nanocrystalline AlCrFeCoNi high-entropy alloy (HEA) coatings were applied on Inconel 718 superalloy using the atmospheric plasma spraying (APS) process. The high-temperature oxidation behavior of the microcrystalline and nanocrystalline AlCrFeCoNi HEA-coated superalloy was examined at 1100 °C under the air atmosphere for 50 cycles under cyclic heating and cooling (1 h for each cycle). The oxidation kinetics of both nanocrystalline- and microcrystalline-coated superalloys were accordingly analyzed by weight change measurements. We noted that the uncoated and coated samples followed the parabolic rate law of the oxidation. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDS), elemental mapping and X-ray photoelectron spectroscopy (XPS) were used to analyze the oxidized coated and uncoated samples. In the HEA-coated superalloy, Fe, Ni, Co and Al were oxidized in the inter-splat region, whereas the splats, which consisted mainly of Ni and Cr, remained unoxidized. Due to the formation of compact and adhesive thin NiO, CoO oxides and spinels together with the Al₂O₃ oxide scale on the surface of the coating during oxidation, the developed nanocrystalline HEA coating showed better oxidation resistance compared with the microcrystalline HEA coating.

【 授权许可】

Unknown