STRUCTURE AND PHASE TRANSFORMATIONS
IN THE SURFACE LAYERS OF COMPOSITE CERAMIC MATERIALS
BASED ON THE SYSTEMS (TiN–AlN)–(TiN–Cr
) WITH HIGH-TEMPERATURE OXIDATION
UNDER CONDITIONS OF CONCENTRATED SOLAR RADIATION
T. V. Mosina
Translated from Novye Ogneupory, No. 2, pp. 22 – 26, February 2011.
Original article submitted September 17, 2010.
Results are provided for a study of the formation mechanism and conditions for high-temperature corro-
sion-resistant coatings, which are formed in air (>1500°C) with cyclic thermal changes under the action
of concentrated energy sources. It is established that in composite materials of the systems
) and (TiN–AlN)–(Ni–Cr)–(TiN–Cr
) a complex oxide film forms that has good
adhesion to a base and undergoes further composite oxidation, i.e., it promotes an increase in its scaling resis-
Keywords: composite ceramic, concentrated solar radiation (CSR), oxidation, corrosion resistance.
Development of contemporary technology is inseparably
connected with a steady increase in working temperature,
loading rates, and the effect of corrosive media. This pro-
vides a requirement for using fundamentally new materials,
which guarantee reliability and the corresponding level of
functional equipment properties. This relates mainly to ce-
ramic and cermet composite materials based on oxygen-free
refractory compounds (nitrides, carbides, borides). Among
the multitude of ceramic materials there is considerable in-
terest in composite materials of the systems TiN–AlN and
, which exhibit a high level of tribotechnical ,
physicomechanical [2, 3], and corrosion properties .
Previously  the effect of concentrated solar radiation
(CSR) on structure and phase transformations in ceramic
composite materials has been studied for the systems
TiN–AlN and TiN–AlN with a metal binder Ni–Cr–Al. It has
been established that in these systems a dense oxide film
forms consisting of two zones, each of which has a complex
heterophase structure. The surface of the oxide film consists
oxides and NiCr
spinel, and the second
layer of oxide film adjacent to the base is tialite b-Al
This film exhibits high adhesion to the base and is a barrier
preventing diffusion of oxygen into a specimen . Action
of CSR on a material is accompanied by occurrence of
physicomechanical processes at its working surface, the
same as rapid heating and cooling, the possibility of focus-
sing energy in a small area, and also reaction of material
components at high temperature.
In order to increase corrosion resistance in air (>1500°C)
and in corrosive media it is necessary to use either a coating,
or a coating of more corrosion-resistant composites. For
these coatings we have proposed composites of the system
. In order to increase coating adhesion to a base a
metal heat-resistant underlayer is used, i.e. Ni–Cr alloys,
which wet well on one side to a ceramic TiN–AlN and on an-
other to composite TiN–Cr
. These metal alloys exhibit
high corrosion resistance and tribotechnical properties.
The aim of this work is to study the mechanism and con-
ditions of forming high-temperature corrosion-resistant coat-
ings in air (>1500°C) with cyclic thermal changes under the
action of concentrated streams of energy in order to explain
coating oxidation under these conditions, and the possibility
of increasing their resistance to high-temperature oxidation.
The structure and structural phase transformations were stud-
ied in ceramic composite materials (TiN–AlN)–(TiN–Cr
MATERIALS AND STUDY METHODS
The starting composite specimens of systems
(TiN – 75 wt.% AlN) were studied by hot compaction at
1700 – 1850°C in graphite molds in a device with induction
Refractories and Industrial Ceramics Vol. 52, No. 1, May, 2011
1083-4877/11/05201-0048 © 2011 Springer Science+Business Media, Inc.
I. N. Frantsevich Institute of Materials Science Problems, Na
tional Academy of Sciences, Kiev, Ukraine.