A novel spinel coating on cobalt‐based Superalloy GH605 via an in‐situ oxidation approach

Abstract

Cr‐Mn‐O spinel coating was prepared on the surface of cobalt‐based superalloy GH605 via an in‐situ oxidation method in H2O‐H2 environment. The composition, morphology, and chemical value state of the oxide spinel coatings were investigated by SEM, EDS, XRD, Raman spectra, and XPS. It indicated that the morphology of coating varied with oxidation temperature, and granular surface appeared when oxidation temperature increased to 1100°C. The formed Cr‐Mn‐O spinel coating was composed of Cr2O3 and MnCr2O4, and the thickness increased significantly with oxidation temperature. In the coating, Cr element existed in the state of Cr3+ ions and Cr6+ ions, while Mn element only existed in the form of Mn2+ ions.

Growth Of A Single MnCr2O4 Spinel On Ni-25Cr-1.5Mn Alloy By The Rhines Pack Method and Photoelectrochemical And Raman Signatures of MnCr2O4 Spinel

“…Their results indicated that Cr-Mn-O spinels possess outstanding chemical stability and favorable carburizing resistance. For this reason, it was envisaged to minimize coke formation in many industrial applications: industrial ethylene furnaces [13], the cracking of light naphta [14], as coating of Co-based nozzle in aero engine system [15]. MnCr2O4 still receives full attention as a coating for interconnects used in solid oxide fuel cell device because of its efficiency to lower chromium species volatilization at high temperature in water vapor atmosphere [16][17].…”