Creep–rupture characteristics of polycrystalline oxide ceramic to 1600°C

Creep in polycrystalline oxide ceramics at temperatures 1400 – 1600°C occurs by diffusion. The creep curves are very sensitive to the presence of nonequilibrium defects and stress concentrators which were “annealed” during cooling after high-temperature kilning of the materials. Apparently, rupture is due to vacancies forming in stretch-zone sections tied to crystal boundaries followed by their coagulation on the boundaries. Cracks form and develop differently in different materials, depending on the crystal-chemical properties of the materials.