Protective Coating from Manganese Cobalt Oxide Powders Obtained by High Energy Ball Milling: Materials Characterization and Cell Environment Testing

摘要

The required application of ceramic coatings on metallic interconnects to avoid corrosion in SOFC oxidizing environment has pointed out the need to find cheap and environmental friendly approaches for the production of coating powders, to be applied by diffused and cost effective wet powder processing techniques like spray and slurry coating methods. High Energy Ball Milling (HEBM) is a mechanochemical powder processing technique here exploited to produce mixed composition coating precursor powders from Mn and Co oxides. The processed compound consists of nanostructured and intimately mixed Mn-Co oxides that rapidly react to produce the high temperature spinel phase during the sintering process. A slurry suspension was formulated and applied on a stainless steel substrate, evaluating the coating behaviour during 500h oxidation test at 800°C by means of Area Specific Resistance (ASR) evolution, X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) analyses.