Production Features of Preparation and Properties of Ceramic Objects Made from a Mixture of Lightlyand Highly-Fired BeO Powder

摘要

Slip casting is used to prepare ceramic objects from a mixture of lightly- (50%) and highly-fired (50%) BeO powder. For additional purification of objects from impurities after burning-off organic binder they are impregnated in sodium carbonate solution of identical concentration with different impregnation duration. The change in electrophysical properties (dielectric permittivity epsilon, dielectric loss angle tg beta) and thermal conductivity lambda of objects made from this ceramic is studied in order to explain the possibility of changing them in electronic devices. It is established that an increase in impregnation time for BeO ceramic specimens in Na2CO3 solution leads simultaneously both to electrophysical property stabilization and also to contamination of ceramic objects with sodium compound impurity, reducing their electrical strength. In order to reduce this effect it is necessary to wash objects carefully from impurities in hydrochloric acid solution after impregnation and heat treatment at 1370 K.