PRODUCTION FEATURES OF PREPARATION AND PROPERTIES
OF CERAMIC OBJECTS MADE FROM A MIXTURE OF LIGHTLY-
AND HIGHLY-FIRED BeO POWDER
V. S. Kiiko
and V. Ya Vaispapir
Translated from Novye Ogneupory, No. 8, pp. 55 – 58, August, 2016.
Original article submitted May 11, 2016.
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 im
pregnated in sodium carbonate solution of identical concentration with different impregnation duration. The
change in electrophysical properties (dielectric permittivity e, dielectric loss angle tgb) and thermal conduc
tivity l 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
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.
Keywords: beryllium ceramic, powder, ceramic object, impregnation, sodium carbonate, electrophysical
properties, impurities, dielectric permittivity, dielectric loss, thermal conductivity, breakdown strength.
Ceramic based on beryllium oxide exhibits a unique set
of physicochemical properties and makes it a prospective
material for use in contemporary electronics, new fields of
engineering, and special instrument building [1 – 6]. The
production and physicochemical properties of BeO ceramic
may vary in relation to type of BeO starting powder, its prep
aration method, morphology, and presence of impurities
[2 – 9]. Previously we have established the effect of original
powder morphology on some properties of objects made
from BeO-ceramic [2,3–9].
There is no large production of objects based on BeO ce
ramic within Russia. In the Ul’binsk Metallurgical Plant
(Ust’-Kamenogorsk, Kazakhstan Republic) objects made
from BeO ceramic are prepared from old reserves of lightly-
fired powder subjected to a whole chain of production con
version [2, 8, 9].
The main stages of technology for preparing lightly-fired
BeO powder from beryllium-containing raw materials, i.e.,
beryllium carbonate or hydroxide (STP 197–84) are:
– original material calcining at 773 K in order to prepare
– preparation of briquettes and calcining at 1473 K, then
milling to a size of 0.315 mm (100%);
– chemical purification with hydrochloric acid solution
and drying the BeO powder obtained at 773 K;
– vibration compaction of BeO powder (BM-50);
– screening of vibration compacted BeO through a
screen with a size of 1.0 mm in order to prepare product in
accordance with TY 95/143–79.
In the Zenit-K plant (previously until 2015 KazMetizProm,
Ust’-Kamnogorsk, Kazakhstan Republic) in view of the lack
of a workshop for stripping beryllium minerals and steady
replenishment of lightly-fired powder reserves the task be
came acute of partial replacement of lightly-fired BeO pow
der by highly-fired material, and at the same time crushing
broken ceramic objects, and grinding them in order to carry
out subsequent production operations. Preparation and prop
erties of ceramic objects using a mixture of lightly- (50%)
and highly-fired (50%) BeO powder for their use in elec
tronic devices has been communicated by us previously
[5 – 7]. In this work average indices are provided for proper
ties of starting powder prepared from a mixture of lightly-
Refractories and Industrial Ceramics Vol. 57, No. 4, November, 2016
1083-4877/16/05704-0423 © 2016 Springer Science+Business Media New York
FGAOU VPO Ural Federal University, Ekaterinburg, Russia.
OAO Novosibirsk Komintern Plant, Novosibirsk, Russia.