SCIENTIFIC RESEARCH AND DEVELOPMENTS
DEFORMATION OF NONFIRED REFRACTORIES
ON PHOSPHATE BINDERS. 4. DEFORMATION
DUE TO HEATING AND CREEP OF CEMENT COMPOSITION*
V. S. Bakunov
and U. Sh. Shayakhmetov
Translated from Novye Ogneupory, No. 4, pp. 30 – 35, April, 2007.
Original article submitted October 12, 2006.
Results of a study of deformation due to heating and of creep of phosphate materials are presented. The range
of necessary loads and the rate of temperature growth under nonisothermal conditions are determined. The
role of the grain composition of the filler (a-Al
) of the model alumophosphate cement composition is
The next stage was a study of high-temperature deforma-
tion of cements. Basing ourselves on requirements on the use
refractories, we studied the behavior of materials in the pro-
cess of heating and under isothermal conditions. Therefore,
the experiments were primarily performed in a mode of heat-
ing at a constant rate and holding at the chosen temperature
with or without application of a constant external load.
We will begin with the results of preliminary studies [13,
21, 24] aimed at determining the effect of the load, of the rate
of temperature growth under isothermal conditions, and of
the grain composition of the filler for refractories of model
composition. Figure 10 presents the deformation of model
composition due to heating of test pieces under different
loads. All the curves obtained for test pieces preliminarily
heat treated at 300°C have an inflection at 450 – 750°C,
which disappears when the temperature of the preliminary
heat treatment is increased to 900°C or higher values
(Fig. 11). The beginning of the inflection is connected with
interaction of the components and evolution of the cement
skeleton formed due to the preliminary heat treatment to
300°C. These structural changes are a result of polyconden
sation and of formation of polyphosphates; above 600°C the
changes occur due to the decomposition of [Al(PO
polymer phosphates and other phase trans
It follows from the data of Fig. 10 that up to about
1100°C the test piece expands and the expansion is the lower
the higher the load applied; under higher temperatures the
test piece undergoes compression. The temperature at which
the compression begins increases from 1100 to 1250°C upon
growth in the temperature of the preliminary heat treatment
of the composition (see Fig. 11). The cement acquires a
stable structure after preliminary treatment at 900°C with a
hold of 1 h. Such test pieces contain the initial a-alumina,
aluminum orthophosphate (the C-form), and
aluminum metaphosphate (the A-form). In heating
of test pieces preliminarily heat treated at 1400°C (see curve
Refractories and Industrial Ceramics Vol. 48, No. 2, 2007
1083-4877/07/4802-00098 © 2007 Springer Science+Business Media, Inc.
* Continued. See Vol. 48, No. 1, 2007 for the beginning.
Joint Institute of High Temperatures of the Russian Academy of
GUP “BashNIIstroy” Institute, Russia.
400 800 1200 1600
Fig. 10. Deformation e as a function of the temperature t of the
model composition under compressive loads, MPa: 1, 0.04; 2, 0.2;
3, 0.4; 4, 0.6; 5, 0.8.