Composition of beryllium oxide ceramics

The physicochemical and electrophysical properties of ceramics based on BeO without impregnation and after impregnation with an aqueous solution of sodium carbonate Na2CO3 are studied. It is established that impregnation leads to preparation of ceramic specimens with a white color, which develop increased porosity, lower amount of impurities and smaller average microcrystal size, although it has little effect on their electrophysical properties. In order to improve these properties considerably it is necessary to increase ceramic density by increasing its sintering temperature by 20 – 40 K. Values of electrical permittivity δ and dielectric loss tangent tg δ are determined for a series of BeO ceramic specimens (732 pieces), having identical geometric dimensions, but prepared from original BeO powder of different batches. Studies show considerable scatter in the distribution of these parameters, which points to a requirement for further improvement of BeO-ceramic preparation technology.