Journal of the American Ceramic Society, Vol.90, No.9, 2954-2960, 2007
YSZ-Induced crystallographic reorientation of ni particles in Ni-YSZ cermets
Metal-ceramic interfaces in Ni-YSZ (YSZ, yttria-stabilized zirconia)-textured porous cermets prepared by reduction of NiO-YSZ directionally solidified eutectics have been studied by transmission electron microscopy and X-ray pole figure experiments. Before reduction of NiO, the interfacial plane is (1 (1) over bar1)(NiO)||(002)(YSZ), but after reduction, the Ni phase does not maintain the same crystallographic orientation as the NiO parent phase. Ni undergoes an interface-induced crystallographic reorientation to form the lower energy (002)(Ni)||(002)(YSZ) interface. This process has been studied as a function of the reduction temperature, and it seems to be more effective at similar to 800 degrees C. Metal-ceramic low-energy interfaces prevent Ni particle coarsening and impart long-term stability to the cermet.