Co-deposition of CuO and Mn1.5Co1.5O4 powders on Crofer22APU by electrophoretic method: Structural, compositional modifications and corrosion properties

Co-deposition of CuO and Mn1.5Co1.5O4 by single step electrophoretic deposition is used to produce ∼15 µm coatings on Crofer22APU steel, which finds use as interconnect for high temperature solid oxide cells. Sintering of the green coatings in reducing and then oxidizing conditions led to formation of a mixed (Cu,Mn,Co)3O4 spinel. By the incorporation of Cu, the density of the coatings improved. Scanning and transmission electron microscopy observations, supplemented with energy dispersive spectroscopy, confirmed dissolution of Cu in the spinel phase. For the un-doped Mn1.5Co1.5O4 both the tetragonal and cubic phases are detected at room temperature by X-ray diffractometry, whereas the addition of Cu seems to stabilize the cubic phase. Initial (∼1000 h) high temperature corrosion evaluation at 800 °C in air showed promising properties of the mixed spinel coating.