Suspension and process parameters selection for electrophoretic deposition of Mn-Co spinel coating on steel interconnects

Metallic interconnect coatings, consisting of MnCo2O4 spinel, were effectively applied to Crofer 22 APU using the electrophoretic deposition (EPD) method in both H2O: ethanol and pure ethanol solvents. The primary goal of this method was to prevent chromium migration, minimize evaporation, and control the oxidation rate. The study aimed to assess the quality, adhesion, and thickness of the Mn-Co coating, with the objective of achieving a consistent and uniform layer. The results indicated a preference for pure ethanol solvent over H2O: ethanol (40:60 %Vol) for Mn-Co particles. Furthermore, the agglomeration of Mn-Co particles was notably lower (approximately 7 times) in ethanol compared to H2O: ethanol. The morphology and surface roughness of the sintered Mn-Co coating on the alloy were examined using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). A uniform and dense coating was successfully attained using pure ethanol solvent at a solid concentration of 10 g/L, with 0.5 g/L of iodine serving as a disperser. The deposition process, carried out at a voltage of 30V for 20 s, resulted in a coating with a thickness of 7.4 +/- 0.3 mu m and a surface roughness of 0.75 +/- 0.5 mu m.