Recrystallization of Beryllium Oxide Bodies at 2000°c.*

A bstract Recrystallization is an important factor in the preparation of very dense pure oxide ceramic bodies. The work described in this paper shows the effect of the original particle size on the degree of recrystallization of beryllium oxide bodies. A water elutriator for particle‐size separation in the subsieve range and an oxyacetylene furnace with zirconia refractories for operation at 2000°C. are described. The microscopic examination of prepared thin sections and the X‐ray diffraction back‐reflection method are used to determine particle sizes and the degree of recrystallization. Shrinkage during firing is found to be approximately constant for all particle sizes originally below 10 microns and decreases in a regular manner with increasing particle size. The recrystallization factor for beryllium oxide is found to vary from 40 for 1.25‐micron particles to 2.5 for 10‐micron particles.