A Ni-doped Al2O3 coating was prepared on Ti-45Al-8.5 Nb alloys by the cathodic plasma electrolysis (CPE) process in a 1.2 mol/L Al(NO3)(3) ethanol solution containing different concentrations of Ni(NO3)(2) . The coatings deposited in these solutions mainly consisted of gamma-Al2O3, NiAl2O4 and some metallic Ni. The Ni-doped Al2O3 coating exhibited increased oxidation resistance and adhesion compared with that of a pure Al2O3 coating. The mass gain of the Ti-45Al-8.5 Nb alloys after oxidation was significantly reduced if Ni was added to the coating. A large number of craters on the coating surface were filled with NiAl2O4 and metallic Ni that inhibited the oxide from contacting the substrate through the craters and pores. The metallic Ni and Al2O3 were also transformed to NiAl2O4 during oxidation at 900 degrees C. The structure of the coating was also stabilized by the formation of NiAl2O4 . Therefore, the addition of Ni can be used as a sealing technology for ceramic coatings prepared by the CPE process. (C) 2018 Elsevier B.V. All rights reserved.