High‐Temperature Creep and Dislocation Etch Pits in Polycrystalline Beryllium Oxide

Abstract

Compressive creep of high‐density polycrystalline beryllium oxide was investigated in the range 1850° to 2050°C. Creep rate was dependent on the applied stress to the 2.5 power, and the apparent activation energy for creep was 145 kcal/mole. Etch pit studies showed that the dislocation density in tested specimens was two orders of magnitude greater than that in assintered material. The diffusion process controlling creep was ascribed to volume diffusion of the anion. The deformation behavior was governed by dislocation motion.