REFRACTORY STRUCTURES MADE OF LOW-WEIGHT CARBON-BONDED
S. A. Kolesnikov
and G. A. Kravetskii
Translated from Novye Ogneupory, No. 8, pp. 26 – 30, August, 2007.
Original article submitted February 5, 2007.
Published data on the use of high-porosity low-weight carbon-bonded carbon-fiber-reinforced (CBCR) com
posite structural materials in high-temperature technology are generalized. It is shown that large-scale struc
tures can be created from CBCR composites at a quite small material weight consumption. Such structures are
characterized by low weight and small temperature-induced deformations, which ensure long service life and
reliable thermal isolation, for example, of metal furnace shells. Methods for the assembly of CBCR structures
by mechanical means or using heat-resistant glues are proposed.
Heat-resistant structures made of porous carbon-bonded
carbon-fiber-reinforced (CBCR) composite materials find in-
creasing use in modern industry. The main fields of applica-
tion for such CBCR composites are electrovacuum technolo-
gies developed, in particular, for the thermovacuum treat-
ment of turbine blades, ion-beam processing of gears, and
heat-resistant alloy production by means of directional crys-
tallization. Screened-vacuum furnaces, in which carbon-
based composites are employed, are used in various techno-
logical processes (see Table 1) . It was reported that car
bon-based composite thermal insulation could be used in nu
clear power industry for the creation of structures in the inner
zones with temperatures up to 1000°C .
The large-scale production of low-weight CBCR thermal
insulation is well developed in the USA (Union Carbide cor
poration) , Germany (Sigratherm and Sigraflex compa
nies) , United Kingdom (Calcarb Ltd.) [5, 6], and Russia
. For example, in recent years, a low-weight CBCR com
posite TUM-1 (Nampex company) finds increasing use in
the Russian aircraft engine technology . This material is
prepared by dry blending of pulverbakelite, carbon fibers,
and some other components.
In order to increase the strength and rigidity of assem
bled structures, the seams can be glued from inside and out
side with stripes of carbon-reinforced tissues. Such structures
admit multiply repeated technological assembly – disassem
bly cycles .
In recent years, refractory properties of structural CBCR
composites have been increased by introducing silicon car
bide , magnesium oxide , and boron oxide .
In comparison to structural graphite, such CBCR compos-
ites exhibit higher thermal stability, better resistance to im-
pact loading, and increased strength. Owing to this combina-
tion of properties, it is possible to make thin-walled articles
(with a wall thickness below 1.5 mm) and use them as
load-bearing elements of furnaces and related equipment.
CBCRs are also used in low-weight structural heat insulation
of electrovacuum furnaces. In comparison to structural
heat-resistant metals (Nb, Mo), CBCR composites exhibit
Refractories and Industrial Ceramics Vol. 48, No. 3, 2007
1083-4877/07/4803-0223 © 2007 Springer Science+Business Media, Inc.
State Research Institute of Graphite (NIIGrafit), Russia.
TABLE 1. Parameters of Technological Processes in Electrova
Process Temperature, °C
Thermal processing and an
nealing of steels, titanium,
and related alloys
1000 – 1300 Vacuum 10
Annealing of magnetic alloys
(e.g., Nd–Fe–B, Sm–Co)
1000 – 1300 Vacuum 10
Argon 0.05 – 0.1
Annealing of hard alloys and
1350 – 1550 Vacuum 1 – 10
Heat treatment of carbon fila
ments, ribbons, fabrics
1900 – 2000 Argon 0.1
Synthesis and sintering of
powders and articles of Si,
Ti, Zr, W, and B carbides;
Si and Al nitrides; Ti and
Zr borides; ceramic-metal
1700 – 2200 Vacuum 1 – 10
Argon 0.05 – 0.1
Nitrogen 0.05 – 0.1
* For vacuum, residual pressure in pascals.