STUDY OF HIGH-TEMPERATURE DEFORMATION
AND CREEP OF COMPOSITE MATERIALS BASED ON
CORUNDUM AND PYROPHYLLITE RAW MATERIAL
A. R. Murzakova,
U. Sh. Shayakhmetov,
and V. S. Bakunov
Translated from Novye Ogneupory, No. 8, pp. 21 – 24, August, 2012.
Original article submitted March 19, 2012.
Results are provided for a study of high-temperature deformation and creep of composites based on corun
dum, pyrophyllite raw material, and phosphate binder. Data are obtained making it possible to predict material
behavior during operation.
Keywords: pyrophyllite, electrocorundum, deformation, creep.
Materials based on phosphate binders are classified with
respect to composition and structure as complex inorganic
composites whose synthesis is based on acid-basic reaction
and polycondensation of powder filler with orthophosphoric
acid or phosphate binders (metaphosphate solutions) .
Chemical bonding of ceramic materials is quite simple in a
production respect and does not require large energy and
capital expenditure, since heat treatment of objects is carried
out at room temperature or with heating to 600°C (high-tem-
perature is rarely used) [2, 3].
The overwhelming majority of chemical elements of dif
ferent groups of the Mendeleev periodic system may react
under certain conditions with H
, forming phosphate ce
ments. Phosphate binders are considered as homogeneous
solutions of inorganic polymers whose stability and adhesive
properties depend on their chemical composition and P
concentration within a compound .
The method of chemical bonding with phosphate binders
has advantages: the possibility of preparing objects of com
plex configuration with quite high precision for geometric
shape and dimensions; the possibility of manufacture of both
small and large objects with regular engineering properties;
absence of high-temperature firing; absence of loss of mate
rial during object preparation; comparatively high productiv
ity and ease of automation for object manufacture [5, 6].
Pyrophyllite is the most suitable component for binding
granular fillers of refractories and coarse ceramics in phos-
phate material technology. Its distinguishing features are in-
significant volumetric changes on heating, chemical inert-
ness, and high chemical stability; refractoriness depends on
impurity content and is on average 1680°C. Object manufac-
turing technology from composites containing pyrophyllite
in general terms is no different from that for materials within
which there are oxides (Al
, etc.) as the fine fraction
[7, 8]. However, currently there has been little study of the
engineering properties of materials manufactured using
pyrophyllite raw material. The aim of this study was to in
vestigate the high-temperature deformation and creep of
composite ceramic materials based on corundum and
pyrophyllite raw material using phosphate binders.
Electrocorundum fraction 1.5 – 2.0 (No. 125) and 1.2 – 1.3
(No. 12) mm, finely-ground pyrophyllite raw material from
the Kul’-Yurt-Tau deposit (PPR), aluminochromium phos
phate binder (ACPB), and orthophosphoric acid (H
were used for composite manufacture.
Specimen preparation technology for composite materi
als included mixing electrocorundum of two fraction with
phosphate binder, after which portions of finely ground
pyrophyllite raw material were added to a mix and carefully
stirred. Specimens were prepared from the charges by means
of pressing and ramming in relation to amount of phosphate
binder (PB). Compositions with ACPB after holding in air for
seven days acquired a strength specified by s
= 15 – 35 MPa.
Then they were heat treated at 400°C with a rate of tempera
ture increase of 2 – 3 deg/min. In the case of using
orthophosphoric acid specimens were heat treated at a rate of
Refractories and Industrial Ceramics Vol. 53, No. 4, November, 2012
1083-4877/12/05304-0242 © 2012 Springer Science+Business Media New York
Bashkir State Pedagogical University, Scientific-Production Insti
tute, Ufa, Bashkortostan Republic, Russia.
Joint Institute of High temperature, Russian Academy of Sci
ences, Moscow, Russia.