EVALUATION OF THE POSSIBLE USE OF CARBON NANOFILLER
FOR MANUFACTURING SILICIDED OBJECTS
I. A. Bubnenkov,
Yu. I. Koshelev,
O. Yu. Sorokin,
E. G. Cheblakova,
N. I. Polushin,
and N. N. Stepareva
Translated from Novye Ogneupory, No. 12, pp. 32 – 37, December 2011.
Original article submitted September 22, 2011.
Silicided graphites, prepared by SGP technology, using a graphite nanofiller fraction of less than 100 mm, are
promising materials no worse in properties than leading analogs of overseas firms. Nonetheless, in view of the
available raw material base for carbon materials rapid evaluation methods are required for the quality of
graphites used in the manufacture of silicided objects based on them. Volumetric reaction makes it possible to
establish quite rapidly the suitability of test carbon material for manufacturing silicided objects based on them
without recourse to compaction, firing, machining, and siliciding shaped objects. X-ray structural data for the
degree of graphitization of carbon material g, and also a change in its structural characteristics (La and Lc)
during reaction with silicon may be additional criteria for the choice of graphite filler.
Keywords: silicon carbide, silicided graphite, volumetric reaction method, cracks, x-ray structural analysis.
Carbon-silicon carbide materials are currently finding
ever greater application due to their unique mechanical and
thermophysical properties, and a capacity to operate in corro-
sive media, and at elevated temperature. The unique combi
nation of these properties makes it possible to use compo
nents and structures based on them in such areas as metal
lurgy, petrochemical engineering, etc. The main carbon-sili
con carbide materials are currently sintered silicon carbide,
carbon-ceramic composite materials based on carbon-carbon
composite materials (CCCM), and silicided graphites.
In the last few years in both overseas and domestic publi
cations there have been a number of works concerning
self-bonded and sintered silicon carbide, and carbon-ceramic
materials. In addition, many overseas companies, such as
Morgan AM&T (Great Britain), Schunk (Germany),
CoorsTek (USA), devote particular attention to materials
similar in properties and preparation technology to silicided
graphite. By exhibiting a unique combination of the proper
ties of graphite and silicon carbide, this class of materials has
high thermal shock resistance, high-temperature strength,
and tribological properties.
Grades of silicided graphite SG-M and SG-T available
within Russia, prepared by impregnation of graphite grades
PROG-2400 and PG-50 correspondingly with molten silicon,
do not make it possible to achieve high properties (Table 1)
comparable with those for materials SC-DSG (SC-35). This
is mainly connected with the impossibility of controlling
their porous structure and reaction capacity with respect to
silicon, due to the structural properties of industrially pro
duced graphites PROG-2400 and PG-50. It is apparent that in
order to create silicided graphite with properties no worse
than (or exceeding) those of an overseas analog, it is neces
sary to select a graphitized filler with strictly prescribed
properties for manufacturing silicided objects based on them.
Considering this, silicided graphite grade SGP, prepared
by impregnation with molten silicon of a specially prepared
carbon base, is most promising since it is possible to control
carbon base structural porosity and select a graphitized filler
with stable supercrystalline structural characteristics, density,
specific surface, and level of graphitization, and with a low
impurity content. Silicided graphite grade SPG manufactur
ing technology, similar to that described in , includes
preparation of a graphitized filler of the required grain size
composition, mixing with a binder, compaction, firing, sili
ciding, and object machining.
An end to the production of previously used low-sulfur
pyrolyzed petroleum coke grade KNPS  and graphite
based on it with stable properties, and also a difference in
Refractories and Industrial Ceramics Vol. 52, No. 6, March, 2012
1083-4877/12/05206-0431 © 2012 Springer Science+Business Media, Inc.
OAO NIIgrafit, Moscow, Russia.
National Research Technological University MISiS, Moscow, Russia.