EFFECT OF A TiC COATING ON THE STRESS-STRAIN STATE
OF A PLATE OF A HIGH-DENSITY NITRIDE CERAMIC
UNDER NONSTEADY THERMOELASTIC CONDITIONS
V. V. Kuzin,
S. N. Grigor’ev,
and M. A. Volosova
Translated from Novye Ogneupory, No. 9, pp. 52 – 57, September, 2013.
Original article submitted June 27, 2013.
An original method is presented to obtain relations which describe how the thickness and thermal conductivity
of a TiC coating are related to the temperatures, displacements, and stresses in a nitride ceramic plate under
nonsteady thermoelastic conditions. It is shown that the stress-strain state of parts made of high-density ce
ramics can be controlled under such conditions by the application of coatings.
Keywords: plate, coating, nitride ceramic, stress-strain state, nonsteady thermoelasticity.
The expert predictions made on the durability of
high-density ceramic parts used in high-temperature equip-
ment and power plants often do not accurately reflect the
parts’ actual effective length of service. The main reason for
such discrepancies is that the parts are used under nonsteady
conditions . The transient service conditions mean that the
given ceramic part is subjected to a considerably more com
plex set of external loads than it would be in steady-state op
erating regimes. The nonsteady loading conditions accelerate
the nucleation and growth of cracks in the surface layer of
brittle parts and can result in their sudden failure [2, 3]. Pro
cesses that take place in the ceramic under cyclic thermal
loads pose a particularly large danger for these parts .
One possible solution to this problem is the application
of coatings to ceramics [5, 6]. It was shown in  that it is
possible to control the stress-strain state of ceramic parts
through the application of coatings for steady-state operating
regimes. However, there has not been enough study of the ef
fect of a coating on the stress-strain state of high-density ce
ramic parts under transient thermal loads. The problem that
needs to addressed is thus clear - study the effect of the main
characteristics of the coating on the stress-strain state of parts
made of high-density nitride ceramics when the parts are
subjected to nonsteady thermoelastic conditions.
METHOD OF INVESTIGATION
It is almost impossible to solve the stated problem by ex-
perimental methods. We therefore resorted to computer mod-
eling by a method based on the approach described in
[8 – 10].
First we constructed a microstructural model of a ce-
ramic part, designated P1, that in the course of its use comes
into contact with a part made of another material - part P2
(see Fig. 1a ). Part P1 is made of a high-density ceramic and
has a coating on its working surfaces. The two parts come
into contact with one another over two surfaces. Part P2
transmits the service loads (shock loads F, mechanical loads
P, and thermal loads Q) to part P1. These loads act on contact
surfaces having the lengths l
The microstructural model was employed to create the
design scheme with the use of the following assumptions:
1) the given problem is two-dimensional; 2) the ceramic and
the coating are homogeneous and defect-free materials
(pores and cracks are not among the components of their
structure); 3) the ceramic plate and the metallic part do not
undergo plastic deformation; 4) the shock loads that act on
the plate are replaced by concentrated forces.
The design scheme that was created (Fig. 1b ) character
izes a structure whose base element is a plate made of a “ho
mogeneous” high-density ceramic P1 that has an edge with
the radius of curvature r. There are N layers of the thickness
(j = 1, 2, ..., N) on the horizontal and vertical surfaces of
the plate, and each layer can have its own unique properties.
It should be pointed out that a certain number of the N layers
Refractories and Industrial Ceramics Vol. 54, No. 5, January, 2014
1083-4877/14/05405-0376 © 2014 Springer Science+Business Media New York
Moscow State Technical University “Stankin,” Moscow, Russia.