STRUCTURAL CERAMIC AND FIBROUS MATERIALS
BASED ON QUARTZ GLASS
A. G. Romashin,
M. Yu. Rusin,
and F. Ya. Borodai
Translated from Novye Ogneupory, No. 10, pp. 13 – 18, October, 2004.
Original article submitted September 3, 2004.
Ceramic and fibrous materials based on quartz glass with controlled porosity (0 to 90%) and technologies for
fabrication of complex-shaped components developed at the Tekhnologiya Research and Production Enter
prise are described. Properties of structural ceramic and heat-protecting fibrous radio transparent materials for
use in aerospace and aircraft technologies are reported. Techniques for improving the strength of thin-walled
ceramic shells operating under heavy-duty conditions are described.
Development of aerospace technology has stimulated a
search for ceramic materials that would combine high ther-
mal stability, low heat conductivity, and constancy of dielec-
tric properties over a wide range of temperatures and fre-
quencies. The materials had to be resistant to optical, high-
frequency and ionizing radiation and be operable in vacuum
and in oxidizing and reducing media. These requirements
were adequately met by materials based on amorphous sili-
con oxide (quartz glass) that could be prepared by a ceramic
technology using powdered or fibrous raw products.
Ceramic materials based on quartz glass are a relatively
recent addition to the class of inorganic materials [1, 2].
Studies that were conducted in the U.S.A. and the USSR in
the late 1950s have led to a range of structural and heat-pro
tecting materials differing in properties and manufacturing
technologies. A conventional classification was proposed:
vacuum-dense ceramics (open porosity P = 0), structural
(P = 5 – 15%) and porous (P = 20 – 25%) ceramics, high-po
rosity heat-protecting materials (P = 60 – 95%), unfired ce
-based modified materials, laminated ceramic
composites, and ceramic castables.
The increased interest in materials based on amorphous
silicon oxides stems from three factors:
1. The unique set of dielectric, thermophysical, and
chemical properties; as regards parameters such as thermal
stability, radio transparency over a wide range of tempera
tures and frequencies, and heat protecting properties, these
materials have no analogs, which makes them unmatched in
research and technology.
2. Ease of fabricability, large reserves of raw materials in
many countries over the world, and readily available, simple
technological equipment. Practically any established method
in ceramic engineering can be used to treat quartz ceramics;
the low shrinkage at drying and sintering temperatures
(0.5 – 2.0%) makes it possible to fabricate large-size compo-
nents without buckling and strain.
3. These materials have much room left for further up
dating and modifying to obtain products with high reliability
and tailored properties.
By properly modifying the treatment of raw materials
and semi-finished products, molding techniques, and drying
regimes, a technology was developed for materials and com
ponents with porosity varying from 0 to 90% .
Properties of ceramic and fibrous inorganic materials
based on quartz glass are summarized in Table 1. For ce
ramic materials, the basic technology is aqueous slip casting
in plaster molds followed by sintering, and for fibrous mate
rials — isostatic pressing in perforated press-molds (to expel
water from aqueous fiber mixes) followed by drying and
sintering. These simple shaping techniques make it possible
to prepare thin-walled shells, for example complex-shaped
large-size aerial fairings.
Detailed studies into the physical chemistry of grinding,
molding, and sintering made it possible to optimize the pro
cess parameters (granular composition, moisture content,
viscosity, slip pH) and conditions for shaping, drying, and
Refractories and Industrial Ceramics Vol. 45, No. 6, 2004
1083-4877/04/4506-0387 © 2004 Springer Science+Business Media, Inc.
Tekhnologiya Research and Production Enterprise, Obninsk,
Kaluga Region, Russia.