SCIENTIFIC RESEARCH AND DEVELOPMENTS
DEFORMATION OF UNFIRED REFRACTORIES BASED
ON PHOSPHATE BINDERS. 2. DEFORMATION OF UNHARDENED
CEMENTS IN HEATING AND COOLING CYCLES
V. S. Bakunov
and U. Sh. Shayakhmetov
Translated from Novye Ogneupory, No. 2, pp. 38 – 42, February, 2007.
Original article submitted November 22, 2006.
Results are provided for an experimental study of the deformation of an unhardened aluminophosphate
cement composite with cyclic heating and cooling regimes without a mechanical load and under load.
The data obtained are important for phosphate material technology since they make it possible to substantiate
the choice of the optimum treatment regime and operation.
Using experience of work in the field of high tempera-
ture technology  and taking account of the features of
test materials a procedure has been proposed for performing
experiments and processing the data obtained. It includes set-
ting up tests for measuring specimen deformation without
applying an external mechanical load and with a compres-
sive force in different thermal regimes. The procedure has
been implemented in specially designed and manufactured
equipment [17, 18].
At first the change in cement specimen dimensions was
determined with cyclic heating and cooling temperature re
gimes: here information was obtained about the temperature
field for occurrence of individual processes in a complicated
interweaving of different sources of deformation. In fact, in
these tests a study was made of the behavior of unfired mate
rials with primary heating and as necessary with subsequent
cycling: these data have an independent value for solving ap
plied problems. The deformation study was carried out in
temperature ranges for changes in their structure; hardening
at about up to 300°C, softening (or strengthening) at 300 –
1000°C, and sintering observed above 1000°C .
These tests are also important in other aspects. They will
make it possible to improve the technology for preparing ce
ment and composite materials based on it, and also to evaluate
their deformation resistance during operation under condi
tions of variable temperatures and mechanical loads .
In accordance with the proposed prototype procedural
approaches  in subsequent procedures were selected for
evaluating the behavioural characteristics of ceramics and
refractories in test regimes for deformation under load and
creep. The first tests were considered as preliminary experi-
ments making it possible to establish temperature time and
other ranges for subsequent more detailed tests on the defor-
mation of composites. The second tests give information
about kinetic features of the process and the effect on its path
of different factors, including material structure .
In the next stage a study was made of deformation fea
tures in a creep regime [7, 13, 21]. Experiments were per
formed in different regimes: with a rapid or slow increase in
temperature up to the required level. In the first case all pro
cesses causing deformation shifted in the direction of higher
temperatures and they occur under essentially non-equilib
rium conditions. In fact this case studies the behavior of
non-equilibrium structures. Determination of deformation in
a regime of comparatively slow heating makes it possible to
study the behavior of almost equilibrium structures since at
each temperature, particularly at high levels, an equilibrium
material state (or close to it) is achieved.
Previously a study was made of the overall picture of
composite material deformation both with a continuous in
crease in temperature and with isothermal soaking. Then the
effect of production factors on creep was clarified.
Refinement of the test procedure was performed on com
posites with a composition of finely-ground alumina-phos
phate binder. Here it was assumed that Al
on mixing with
Refractories and Industrial Ceramics Vol. 48, No. 1, 2007
1083-4877/07/4801-0049 © 2007 Springer Science+Business Media, Inc.
* Continuation, Started in No. 1, 2007.
Joint Institute of High Temperatures, Russian Academy of Sci
ences, GUP Institute BashNIIstroi, Russia.