UHF-ENERGY ABSORBENTS BASED ON PRODUCTS
OF ALUMINUM-MAGNESIUM ALLOY CHEMICAL DISPERSION PRODUCTS
S. G. Ponomarev,
V. P. Tarasovskii,
V. I. Koshkin,
and Yu. M. Borovin
Translated from Novye Ogneupory, No. 5, pp. 54 – 57, May, 2016.
Original article submitted December 6, 2015.
Results are given for studying electrophysical properties of ceramic materials based on powders prepared by
chemical dispersion of aluminum-magnesium alloys. The possibility is demonstrated of using these materials
as UHF-energy bulk absorbents. It is shown that good test material thermal stability makes it possible to use it
as heat insulation and refractory material in systems requiring protection from UHF-energy.
Keywords: UHF-energy ceramic absorbents, ultrafine powders, electrophysical parameters.
Absorption of UHF-energy (ultrahigh-frequency region
of electromagnetic vibration energy) is an integral part of the
overwhelming majority of electrovacuum, radioelectronic,
and other instruments and devices [1, 2]. Their use is ex-
tremely varied: high-frequency isolators, absorbers of stray
forms of vibrations, matched loads, etc. Among the multi-
tude of known UHF-energy absorbing materials the most
promising are so-called bulk absorbers. The main specifica-
tions for these materials emerges from their purpose, i.e.,
UHF-energy absorption, conversion of it into heat, and dissi
pation of excess energy. In other words, these materials
should have high dielectric permittivity e, dielectric loss an
gle tgd, and thermal conductivity l. In addition, they should
be cheap and quite light in order not to add weight to an in
strument in which they are used.
The range of materials for creating absorbents is quite
extensive. For example, this may composite materials based
on powder ferrite and polymer binder. However, use of these
materials is limited to 100 – 200°C. Currently there is exten
sive use of ceramic materials as absorbers . These materi
als withstand heat up to 1000°C and may be dielectrics (for
example material VKT93-1 of Al
with addition of SiO
CaO, and TiO
), or semiconductor-dielectrics (for example
KT-30 made of TiO
). In the first case the specific volumet
ric electrical resistance r of the material is of the order of
W·m, and in the second it is 10
of UHF-energy absorbers from these materials is connected
with significant difficulties since firing them is performed at
1900°C in a hydrogen atmosphere. Therefore the task of cre-
ating ceramic materials for UHF-energy absorbers sintered at
relatively low temperature in an air atmosphere is currently
Recently in FGBOU MAMI ceramic materials made
from powders prepared by chemical dispersion of aluminum
alloys in alkali solution have been studied successfully [4, 5].
Synthesized ultrafine powders make it possible to prepare
porous refractory ceramic materials with good mechanical
properties [6, 7]. It should be noted that in preparing powders
by this procedure a unique combination of oxides of the dif
ferent metals arises that may have a marked effect on electro
magnetic properties of ceramic materials created based on
The aim of the present work is to study electrophysical
and radio-absorbing properties of ceramic materials prepared
from products of chemical dispersion of aluminum-magne
sium alloys. The procedure for preparing starting powders
has been described in [4 – 7]. Powder P1 was prepared from
alloy with 6 wt.% Mg, powder P2 from alloy with 12 wt.%
Mg, and powder P3 from alloy with 20 wt.% Mg (Table 1).
Powders used in the present study contained particles with a
size less than 50 mm. Several series of ceramic specimens
K2, K2, and K3 were prepared respectively from powders
P1, P2, and P3. Specimens were molded by two-sided
semidry compaction under a pressure of 150 MPa. The tem
porary process binder used was 10% solution of polyvinyl al
Refractories and Industrial Ceramics Vol. 57, No. 3, September, 2016
1083-4877/16/05703-0279 © 2016 Springer Science+Business Media New York
FGBOU VO Moscow State Engineering University (MAMI),
ZAO NTK Bakor, Shcherbinka, Moscow Region, Russia.
FGAOU VO Sevastopol’ State University, Sevastopol’, Russia.