Microstructure and electrical conductivity of Ni-YSZ cermets prepared by combustion synthesis method

Ni-YSZ cermets were prepared by combustion synthesis of Y(NO ₃)₃, Zr(NO₃)₄, Ni(NO ₃)₂ and urea followed by hydrogen reduction at 800°C. The microstructure and electrical conductivity of Ni-YSZ cermets were investigated as contrasted to those of the cermets with the same Ni contents prepared by mechanically mixing method. The cermets prepared by combustion synthesis method had better homogeneity of Ni distributed in YSZ than those prepared by mechanically mixed method; thus, both Ni and YSZ phases formed, to a certain extent, a continuous network structure. The electrical conductivity of the cermets prepared by combustion synthesis method was always better than that obtained with the samples prepared by mechanically mixed method.