STRESS INHOMOGENEITY IN A CERAMIC SURFACE LAYER
UNDER ACTION OF AN EXTERNAL LOAD.
PART 2. EFFECT OF THERMAL LOADING
V. V. Kuzin,
S. N. Grigor’ev,
and V. N. Ermolin
Translated from Novye Ogneupory, No. 12, pp. 35 – 39, December, 2013.
Original article submitted October 14, 2013.
Results are provided for a comprehensive study of stress inhomogeneity in a ceramic surface layer based on
zirconium dioxide under action of thermal loading. High stress inhomogeneity is revealed in ceramic struc
tural elements. A requirement is noted for considering stress inhomogeneity in describing a wear and failure
mechanism, and also in designing objects of this ceramic for prescribed operating conditions.
Keywords: ceramic, inhomogeneity, stress-strained state, surface layer, modelling, zirconium dioxide,
Intensification of a heating regime for operating contem-
porary machines and an increase in specifications for their
reliability gives rise to special requirements for structurally
inhomogeneous material properties, from which the most
loaded components are manufactured. These requirements
are realized mainly due to optimizing a set of material prop
erties, providing increased deformation and failure resistance
under action of a thermal load [1, 2]. In spite of apparent
progress in implementing this approach, the probability of
sudden failure of high-temperature machine components re
mains quite high , and this considerably limits the pros
pects for effective application of new materials, including ce
ramic materials [4, 5].
The basis of this problem is an insufficient study of the
nature of thermal stress formation, having a marked effect on
ceramic material behavior under action of a thermal load.
Correlation of component shape and size, material proper
ties, heating regime, and heat transfer conditions with ther
mal stresses of order I [6, 7], appear to be the most studied.
The effect of various factors on thermal stresses of order II,
forming in structural elements of inhomogeneous materials
and at their boundaries, has not has such fixed attention. It is
possible to explain this fact by the increased complexity of
the problem due to the following requirements:
– consideration of structurally inhomogeneous materials
formed by elements having different shape, size, and proper-
– rational choice of a model with whose use it is possi-
ble to consider the main material structural features;
– development of a special procedure for calculating
stresses in structural elements of inhomogeneous materials
A procedure for studying stress inhomogeneity in the
surface layer of ceramic under action of an external load,
whose use has been studied for the effect of a complex me
chanical stress , has made it possible to fill a marked gap
in knowledge. The aim set in this work is studying stress
inhomogeneity in a surface layer of ceramic of zirconium di
oxide as a result of thermal loading.
Solution of the formulated problem was based on numer
ical modelling of deformation processes using a set of mod
els [11. 12]. The procedure for performing an experiment has
been described in detail in the first part of this work .
Therefore, we only note here the more important conditions
of the procedure.
The design layout is presented in the form of a structure
consisting of fragments of components D1 and D2 made of
ceramic and copper respectively (Fig. 1). A fragment of com
ponent D1 consists of three grains Z1, Z2, and Z3 of ellipsoi
dal shape, which are fixed in a matrix through intergranular
Refractories and Industrial Ceramics Vol. 54, No. 6, March, 2014
1083-4877/14/05406-0497 © 2014 Springer Science+Business Media New York
FGBOU VPO Moscow State Technological University Stankin,