ANALYSIS OF EXISTING RADIOPARENT REFRACTORY MATERIALS,
COMPOSITES AND TECHNOLOGY FOR CREATING HIGH-SPEED
ROCKET RADOMES. PART 2. COMPARATIVE ANALYSIS OF THE MAIN
PROPERTIES OF MATERIALS USED FOR CREATING ROCKET RADOMES
E. I. Suzdal’tsev,
D. V. Kharitonov,
and A. A. Anashkina
Translated from Novye Ogneupory, No. 7, pp. 38 – 44, July 2010.
Original article submitted February 25, 2010.
Three main materials are considered: sitall, high-alumina and quartz ceramic, currently used for creating
rocket radomes. Physicotechnical properties of the materials are provided: thermal shock resistance, thermal
conductivity, dielectric permittivity, dielectric loss tangent, and also stability during component operation.
Keywords: radioparent refractory material, radome; sitall, high-alumina ceramic, quartz ceramic, refractori
ness, thermal shock resistance, LTEC, strength, elasticity, dielectric permittivity.
In the first part of this article it was noted that currently
before the stage of extensive introduction into production of
high-speed rocket radomes three types of materials were in-
troduced: sitall, high-alumina and quartz ceramics. Sitall
(pyroceram 9606, pyroceram 9608, AC-418, AC-370, etc.)
are materials used both in the USA and within Russia for
manufacturing rocket radomes of the land-air and air-air
classes, operating at velocities up to M = 6. This material has
been particularly extensively for manufacturing objects and
marine and aerodrome bases. In view of the absence of mate
rial porosity it is distinguished by high resistance to pro
longed action of sea water, dust, increased moisture content,
even without using panted coatings .
High-alumina materials are used for manufacturing
rocket radomes of the air-air class, operating at velocities up
M =3–4.There is particularly extensive use of this material
in the USA for rocket radomes of Sparrow type . Within
Russia this class of material is not used for manufacturing ra
domes for a whole series of reasons given below.
Quartz ceramic has found extensive use both in our
country and abroad for high-speed rockets of different
classes, operating at velocities up to M =8[1–6].
For high-speed rockets the main requirement for the ra
dome material is undoubtedly refractoriness. High-alumina
ceramic has a clear advantage with respect to this index. The
application temperature of the aggregate state for it is
2050°C, whereas for sitall it is 1220 – 1350°C, and for ce-
ramic materials based on quartz glass it is not higher than
1300°C. However, with one-sided short term heating, that
actually occurs in rocket radomes, the operating capacity of
an object is determined by other factors.
The most marked of then for inorganic refractory materi-
als is thermal shock resistance (resistance to the action ther-
mal shock and thermal cycling loads). The most widespread
experimental criterion for this quality is the temperature drop
through the wall thickness, that the material withstands with
The dependence of temperature drop DT is shown in
Fig. 1 for quartz ceramic, pyroceram 9606 and high-alumina
ceramic on the value of K = ad/2, whose value in nominal
units between 10
corresponds to thermal loads in
the course with entry of space equipment into a dense layer
of atmosphere. A marked advantage of quartz ceramic over
other materials with respect to this parameter is explained
primarily by the favorable combination of strength,
thermophysical and deformation properties [7, 8]
The high thermal shock resistance of quartz ceramic is
determined mainly by the low linear thermal expansion coef
ficient (LTEC), that is significantly lower than for other ce
ramic materials (Fig. 2). In addition, on heating quartz ce
ramic and objects based on it there is stress relaxation. As a
whole series of studies have shown, this phenomenon is ob
served at up to 900°C or more, and the amount of this effect
may strengthened or weakened due to changing the nature of
the raw material and material structure [7, 8].
Refractories and Industrial Ceramics Vol. 51, No. 4, 2010
1083-4877/10/5104-0283 © 2010 Springer Science+Business Media, Inc.
Part 1 of the article, “Analysis of the level of property indices and
limiting possibilities of radioparent inorganic refractory materi
als,” was published in Novye Ogneupory, No. 6, 45 – 49 (2010).
FGUP ONPP Tekhnologiya, Obninsk, Kaluga Region, Russia.