Reorientation of intra- and intergranular particles in sintered Y-PSZ/Co1−xO composites

Yttria-partially stabilized zirconia (Y-PSZ)/Co1−xO composites 1:99 in molar ratio were sintered and then annealed at 1600 °C for 1–100 h in air to produce reorientation of the embedded particles. Transmission electron microscopy (TEM) of all samples indicated the submicron, but not larger, Y-PSZ particles fell into parallel epitaxial orientation with respect to the host Co1−xO grain sharing preferred {111} interface and {100} ledges. Brownian-type rotation of the embedded particles in terms of anchorage release at the interphase interface is indicated by this and our previously studied case of opposite (Y-PSZ)/Co1−xO composites with Co1−xO as the embedded particles. In the present case, however, detachment or bypassing of Co1−xO grain boundaries in the early firing stage already caused significant orientation as well as shape changes of intergranular Y-PSZ particles.