Application of Cr- or/and Al-containing Nanoparticles to Fabricate High Temperature Coatings

Based on the theory of selective oxidation of metals, a new concept of electrodepositing M-Cr, M-Al, and M-Cr-Al high temperature coatings with Cr or/and Al nanoparticles with M (M = Ni, Co or their combination was proposed. The coatings are composed of a nanocrystalline M matrix and numerous dispersed Cr or/and Al nanoparticles, and the unique nanostructure promotes the selective oxidation of Cr or Al at high temperatures. On this basis, a two-step method consisting of “electrodeposition + electrophoretic deposition” was proposed to develop MCrAl nanocomposite coatings containing high contents of Cr and Al. In this paper, the related research and recent progress are reviewed, and the prospects of applying the combined deposition method to fabricate novel MCrAlY(Y₂O₃)/diffusion barrier system with long-term service stability are summarized.