THERMAL STABILITY OF HIGH-TEMPERATURE MATERIALS. PART 1
V. V. Kolomeitsev,
S. A. Suvorov,
and E. F. Kolomeitseva
Translated from Novye Ogneupory, No. 6, June, 2004, pp. 28 – 34.
Original article submitted December 10, 2003.
Theories of thermal stability for high-temperature materials based on the application of static thermoelasticity
equations to nonstationary thermal processes are reviewed. A new criterion for thermal stability, R = ÄT
proposed. A new model, based on the maximum stress theory and the quantum theory of thermal field, is pro
posed; in terms of this model, the stress-strain state of a solid subjected to thermal shock can be determined by
solving equations of thermal strength and heat conduction with allowance made for inertial terms in thermal
stability equations. Thermostability is considered as a physical parameter characterizing the resistance of ma
terials to failure in a nonstationary temperature field.
Thermal stability of high-temperature materials has been
a problem of major concern for researchers; a survey of the
literature on the subject can be found in [1 – 4]. Theoretical
and practical interest in this problem stems out from the fact
that thermal stability is a central property that determines the
operational reliability of high-temperature materials exposed
to intense thermal shock. Numerous materials, owing to their
high thermal stability Ñ structural oxycarbide composites
, refractory castables , high-temperature materials
based on quartz glass and glass ceramics , fibrous heat in
sulators, to name but a few, have gained wide acceptance in
One will note the similarity and difference in objects of
the physical world, viz. the material and the product.
The material is an object of artificial or natural origin
composed of discrete entities characterized by a mass at rest
(atoms, molecules, or combinations thereof), a definite che
mical and phase composition, a micro- and macrostructure,
and physicochemical and physicomechanical properties.
The product (optionally, the engineering component) is
an object of artificial origin which is made up from a mate
rial, it is bounded in space by a surface forming a shape (a
cube, a sphere, a prism, etc.) and is characterized by linear
dimensions, a volume, a geometrical shape, a mass, and
which is intended for a particular application.
It has been argued [1, 2] that thermal stability is not a
physical property, and for this reason, materials should not
be classified in terms of their resistance to thermal shock.
Thermal stability has been defined as the ability of mate-
rials, solid bodies, or structures to sustain temperature
stresses without detriment to their structural integrity [1, 2].
Temperature stresses may arise in a stationary temperature
field (stresses of the zero and second kind) as well as in a
nonstationary (transient) temperature field (stresses of the
first kind) .
In theoretical and practical studies of the thermal stabil-
ity, emphasis is placed on macroscopic thermoelastic stresses
of the first kind whose magnitude is controlled by a range of
factors such as the temperature and rate of thermal loading,
initial temperature of the solid, its modulus of elasticity, and
thermal expansion coefficient.
At low thermal loading rates (defined in terms of the
temperature field variation), the stress and strain state (SSS)
of a solid can be determined, in specific cases, by simulta
neously solving equations of heat conduction and thermo
In a solid subjected to a sudden heat pulse, acoustic
stress waves  or shock waves  are generated that arise
from the fast movement of material particles experiencing
thermal expansion. In this case, an adequate picture of the
onset and propagation of thermoelastic stresses is provided
by solving a dynamic problem of thermoelasticity with al
lowance made for inertial terms. An analytical solution of
some dynamic problems has been considered in . Later,
this approach was extended mainly to metal and composite
structural elements subjected to shock wave effects [9, 11].
For all importance of dynamic problems, practical inter
est was mainly focused on static problems of thermoelasti
Refractories and Industrial Ceramics Vol. 45, No. 5, 2004
1083-4877/04/4505-0327 © 2004 Springer Science + Business Media, Inc.
St. Petersburg State Technological Institute (Technical University,
St. Petersburg; Moscow Technological College, Moscow, Russia.