Properties of hybrid TiN/Al₂O₃ coatings using electron beam melting
New experimental results on studies of the structure, element and phase composition of hybrid coatings deposited on a substrate of stainless steel AISI 321 are presented using combined application of several methods of coating deposition (plasma-detonation and vacuum arc ones) with subsequent...
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Науковий фізико-технологічний центр МОН та НАН України
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| Zitieren: | Properties of hybrid TiN/Al₂O₃ coatings using electron beam melting / M.K. Kylyshkanov // Физическая инженерия поверхности. — 2007. — Т. 5, № 3-4. — С. 149–154. — Бібліогр.: 5 назв. — англ. |
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irk-123456789-988262016-04-19T03:02:06Z Properties of hybrid TiN/Al₂O₃ coatings using electron beam melting Kylyshkanov, M.K. New experimental results on studies of the structure, element and phase composition of hybrid coatings deposited on a substrate of stainless steel AISI 321 are presented using combined application of several methods of coating deposition (plasma-detonation and vacuum arc ones) with subsequent surface treatment by a high-current electron beam (HCEB). We found that an increase in the energy density enhanced the processes of mass-transfer and allowed one to produce denser powder coatings. We demonstrated the results of corrosion tests for TiN/Al₂O₃ coatings in their initial state and after electron-beam modification of their surfaces. We obtained an essential increase in the hybrid coating resistance to corrosion in 0.5 M solution of H₂SO₄ after electron beam treatment. Представлено нові експериментальні результати досліджень фазового складу гібридних покриттів TiN/Al₂O₃, осаджених на підкладинку з нержавіючої сталі типу AISI 321 комбінованим способом. Показано, що в процесі кристалізації порошку Al₂O₃ на підкладинці формуються зародки його γ-фази і метастабільних модифікацій. Вакуумно-дугове осадження нітриду титана на підшар Сr або порошку корунду дозволяє сформувати плівку, матриця якої складається з ГЦК-TiN з домішкою його тетрагональної модифікації ε-TiN. Знайдено режими оплавлення поверхні низькоенергетичним потужнострумовим електронним пучком (НСЕП), що дозволяють активувати ряд поліморфних перетворень типу γ-, β-, δ-, θ → α-Al₂O₃ і ε-TiN → TiN і сформувати покриття з α-фази корунду і кубічної модифікації TiN. Представлены новые экспериментальные результаты исследований фазового состава гибридных покрытий TiN/Al₂O₃, осажденных на подложку из нержавеющей стали типа AISI 321 комбинированным способом. Показано, что в процессе кристаллизации порошка Al₂O₃ на подложке формируются зародыши его γ-фазы и метастабильных модификаций. Вакуумно-дуговое осаждение нитрида титана на подслой Сr или порошка корунда позволяет сформировать пленку, матрица которой состоит из ГЦК-TiN с примесью его тетрагональной модификации ε-TiN. Найдены режимы оплавления поверхности низкоэнергетическим сильноточным электронным пучком (НСЭП), позволяющие активировать ряд полиморфных превращений типа γ-, β-, δ-, θ → α-Al₂O₃ и ε-TiN → TiN и сформировать покрытие из α-фазы корунда и кубической модификации TiN. 2007 Article Properties of hybrid TiN/Al₂O₃ coatings using electron beam melting / M.K. Kylyshkanov // Физическая инженерия поверхности. — 2007. — Т. 5, № 3-4. — С. 149–154. — Бібліогр.: 5 назв. — англ. 1999-8074 http://dspace.nbuv.gov.ua/handle/123456789/98826 539.61:669.018 en Физическая инженерия поверхности Науковий фізико-технологічний центр МОН та НАН України |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| language |
English |
| description |
New experimental results on studies of the structure, element and phase composition of hybrid coatings
deposited on a substrate of stainless steel AISI 321 are presented using combined application of
several methods of coating deposition (plasma-detonation and vacuum arc ones) with subsequent
surface treatment by a high-current electron beam (HCEB). We found that an increase in the energy
density enhanced the processes of mass-transfer and allowed one to produce denser powder coatings.
We demonstrated the results of corrosion tests for TiN/Al₂O₃ coatings in their initial state and after
electron-beam modification of their surfaces. We obtained an essential increase in the hybrid coating
resistance to corrosion in 0.5 M solution of H₂SO₄
after electron beam treatment. |
| format |
Article |
| author |
Kylyshkanov, M.K. |
| spellingShingle |
Kylyshkanov, M.K. Properties of hybrid TiN/Al₂O₃ coatings using electron beam melting Физическая инженерия поверхности |
| author_facet |
Kylyshkanov, M.K. |
| author_sort |
Kylyshkanov, M.K. |
| title |
Properties of hybrid TiN/Al₂O₃ coatings using electron beam melting |
| title_short |
Properties of hybrid TiN/Al₂O₃ coatings using electron beam melting |
| title_full |
Properties of hybrid TiN/Al₂O₃ coatings using electron beam melting |
| title_fullStr |
Properties of hybrid TiN/Al₂O₃ coatings using electron beam melting |
| title_full_unstemmed |
Properties of hybrid TiN/Al₂O₃ coatings using electron beam melting |
| title_sort |
properties of hybrid tin/al₂o₃ coatings using electron beam melting |
| publisher |
Науковий фізико-технологічний центр МОН та НАН України |
| publishDate |
2007 |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/98826 |
| citation_txt |
Properties of hybrid TiN/Al₂O₃ coatings using electron beam melting / M.K. Kylyshkanov // Физическая инженерия поверхности. — 2007. — Т. 5, № 3-4. — С. 149–154. — Бібліогр.: 5 назв. — англ. |
| series |
Физическая инженерия поверхности |
| work_keys_str_mv |
AT kylyshkanovmk propertiesofhybridtinal2o3coatingsusingelectronbeammelting |
| first_indexed |
2025-07-07T07:07:51Z |
| last_indexed |
2025-07-07T07:07:51Z |
| _version_ |
1836971009726480384 |
| fulltext |
ФІП ФИП PSE, 2007, т. 5, № 3-4, vol. 5, No. 3-4 149
INTRODUCTION
Servicing characteristics of plasma-detonation
produced powder coatings are mainly determined
by the state of their surfaces (porosity and
roughness) as by well as the physical and mecha-
nical characteristics of deposited materials. It is
known that an oxide aluminum ceramic has good
physical, mechanical and as servicing properties
[1]. One of the ways to harden the ceramic coa-
tings is to deposit TiN films to them and subse-
quently melt them by electron beams, high-pow-
der ion beams and plasma jets. This way inten-
sifies the processes of mass transfer and diffusion
due to intensive heating and melting. Duration
and intensity of heating affects the relief of the
formed surface and the mechanisms of phase
transformations in the deposited materials. The-
refore, to produce hard and simultaneously duc-
tile coatings with a high corrosion resistance
and a good adhesion, one needs a detailed selec-
tion of deposition regimes and subsequent mel-
ting taking into account individual features of
deposited materials.
EXPERIMENTAL METHODS
Protecting hybrid coatings TiN/Al2O3 were ma-
nufactured on a substrate of austenitic stainless
steel AISI 321 (composition: 18wt.% Cr, 9 wt.%
Ni, 1 wt.% Ti, 0.3wt.%Cr, Fe the rest, 1.1mm
thick). Powder coatings of aluminum oxide (45
to 60 µm thick) were deposited using a high-ra-
te pulsed plasma jet by the facility “Impulse-5”
(the regimes (conditions) and techniques for
deposition are presented in [2]).To increase the
corrosion resistance of the protecting ceramic co-
ating and to eliminate defects of the plasma-de-
tonated deposited powder coating in the vacuum-
arc source of “Bulat-3T” type, we additional-
ly deposited films of titanium nitride of 1.5 to
2.0 µm thick. To smooth the surface structure
non-uniformities, to outgas coating bulk and to
enhance diffusion and mass transfer processes
in the “coating-substrate”, we melted the surfaces
of hybrid coatings using a high-current electron
beam. Thermal activation was realized by an
electron-beam accelerator “U-212”.
Mechanical properties of coatings based on
of oxide aluminum depend on the phase com-
position of this material [1]. For example, an inc-
rease of the content of metastable phases in the
near surface region of Al2O3 essentially decreases
the surface hardness and its resistance to the ac-
tion of aggressive media. However, at the same
time, we observed good adhesion of the coatings
with the surface of steel substrates unlike the coa-
tings content 100% of α-phase. The application
of high-energy beams for selected substrate thick-
ness was impossible due to intensive substrate
deformation. Therefore to pack (seal) the powder
coatings, we performed two-time melting of the
surfaces under the following HCEB parameters:
first the coatings were melted by an electron be-
am of 760 W/cm2 power density (U = 30 kB,
IB = 20 mA, νB = 60 m/hour, dB = 0.1 m); then
UDC 539.61:669.018
PROPERTIES OF HYBRID TiN/Al2O3
COATINGS USING ELECTRON BEAM MELTING
M.K. Kylyshkanov
East-Kazakstan State Technological University, (Ust’-Kamenogorsk),
Kazakstan
Received 20.07.2007
New experimental results on studies of the structure, element and phase composition of hybrid coatings
deposited on a substrate of stainless steel AISI 321 are presented using combined application of
several methods of coating deposition (plasma-detonation and vacuum arc ones) with subsequent
surface treatment by a high-current electron beam (HCEB). We found that an increase in the energy
density enhanced the processes of mass-transfer and allowed one to produce denser powder coatings.
We demonstrated the results of corrosion tests for TiN/Al2O3 coatings in their initial state and after
electron-beam modification of their surfaces. We obtained an essential increase in the hybrid coating
resistance to corrosion in 0.5 M solution of H2SO4 after electron beam treatment.
ФІП ФИП PSE, 2007, т. 5, № 3-4, vol. 5, No. 3-4150
the coatings were cooled in the accelerator cham-
ber down to room temperature. After above treat-
ments a part of the samples was used for studies,
the other part was HCEB melted (U = 30 kB,
νB = 60 m, IB = 10, 15, 20, 25 and 35 mA).
The element composition of TiN/Al2O3 and
TiN/Cr/Al2O3 coatings was studied using the Ru-
therford back-scattering (RBS) by the accele-
rating facility UPK-2-1(Nuclear Physics Institu-
te, Almaty, Kazakstan) having 0.8 and 1.5 MeV
proton beam energy and raster electron micro-
scopy with micro-analysis (REMMA-102 micro-
scope with WDS-2 adapter(Selmi, Sumy, Ukrai-
ne).
An analysis of the coating microstructure and
of the transition zone was performed using a me-
thod of selective chemical etching of cross-sec-
tions with a metallographic microscope Neophot
30. To study the non-uniformities of powder coa-
tings we performed an etching of various inclu-
sions by a solution of hydrofluoric acid (50 ml
HF, 50 ml H2O) for 10 minutes. The steel struc-
ture at the transition steel part was determined
after subsequent grinding and etching (t = 5 min)
in hydrochloric acid. The corrosion resistance of
the prepared coatings was studied using electro-
chemical techniques. A saturated calomel elect-
rode was used as a reference electrode and a gra-
phite one was used as an auxiliary electrode for
all measurements. The tests in a 0.5 M H2SO4
solution were performed in the potential region
–1000 to +1500 mV at ambient temperature.
Five rapid scans (scan rate = 25 mV/s) followed
by one slow scan (scan rate = 0.25 mV/s) were
performed on each specimen.
EXPERIMENTAL RESULTS AND
DISCUSSION
As a result of electron beam surface bombard-
ment the coatings are melted and a subsequent
hardening due to heat removal from surface bulk
occurs. The efficiency of these processes depends
on the electron beam energy parameters and on
the physical properties of melted materials. As a
result of high-rate electron deceleration occurring
in the coating material their interaction with
material atoms and electrons is initiated. A the
source is formed in the material bulk and it has a
characteristic maximum at some depth. A degree
of surface heating was determined by solution
of a problem about body heating [3].
According to performed calculations, the
temperature in the coating near surface region
rose to about 890K (In= 10 mA, q = 380 W/cm2);
about 1340 K (In = 15 mA, q = 570 W/cm2);
about 1730 K (In = 20mA, q = 760 W/cm2);
about 2230 K (In = 25 mA, q = 960 W/cm2);
about 3100 K (In = 35mA, q = 1340 W/cm2).
Fig. 1 shows the morphology of hybrid coa-
ting surfaces depending on the value of energy
introduced to an area unit. Since aluminum oxide
and titanium nitride are refractory materials, and
their melting temperatures are respectively
T(α-Al2O3) = 2323 K [4] and T(TiN = 3478 K, a
(non-essential) decrease in surface roughness
(Fig.1b-d) is realized due to partial and full mel-
ting, as well as to the action of shock waves. Ba-
sing on obtained photos for coatings and per-
formed calculations, one can say that the decrease
in surface roughness in the case of fig. 1c is a
consequence of a complex action of temperature
and deformation-wave mechanisms. Near the
melting point the surface relief began to change
significantly (fig. 1c).
One can see non-uniformly formless regions
with an obvious melting distributed over the sur-
face. We consider that these non-uniformities are
themselves the centers of formation of formless
regions. But heating of the powder sublayer is
not enough, since one does not observe an evi-
dent melting of the upper layer of titanium nit-
ride. The coating surface in the region of valleys
has dark inclusions, in which, according to the
performed element analysis, the basic component
is aluminum. Distribution of components over
the surface (as it was the case of one-time mel-
ting) was not uniform (tabl. 1). We should also
like to note that carbon starts to appear in some
local surface regions. This fact can be explained
by a diffusion of this element from the powder
sublayer towards the surface at the moment of
melting.
Action of HCEB with 1340 W/cm2 power
density on the coating surfaces allows heating
of the near surface region to the temperature of
titanium nitride melting. Such regimes of treat-
ment are accompanied by an intensive change
in the geometry of the surface layer of the alumi-
PROPERTIES OF HYBRID TiN/Al2O3 COATINGS USING ELECTRON BEAM MELTING
ФІП ФИП PSE, 2007, т. 5, № 3-4, vol. 5, No. 3-4 151
num oxide surface, which occurs in the zone
whe-re direct thermal action of HCEB leads to a
transition towards an overheated state. The mate-
rial in the near surface region is refined. As a
consequence, the coating roughness decreases.
Near the melting point titanium nitride becomes
more ductile. The coating becomes practically
uniform in its chemical composition. Taking into
account the data on a quantitative element con-
tent, one should note that more intensive material
melting resulted in increased aluminum and
carbon concentration in the surface region toge-
ther with a simultaneous decrease in titanium and
nitrogen content.
According to RBS results, a repeated action
of the high-current electron beam on the surface
under the regime of melting provides an intensive
Fig. 1. Surface morphology of hybrid coatings after electron – beam treatment: a) – an initial state; b) – one cycle
melting (q = 760 Wt/cm2); c), d) – second cycle melting (q = 960 Wt/cm2 and 1340 Wt/cm2); 1, 2 – points of local
element analysis.
a)
b)
c) d)
Table 1
Chemical composition of the surface of
hybrid coatings TiN/Al2O3 (mas. %)
Region
of
analysis
Other
ele-
ments
N O Al Ti C Si Fe
U = 30 kV, IB = 25 mA, vB = 60 m/hour, fig. 1c
U = 30 kV, IB = 35 mA, vB = 60 m/hour, fig. 1d
p. № 1 0.69 39.93 56.04 3.34 – – – –
p. № 1 19.01 – 10.35 70.21 – – 0.43 –
p. № 2 26.67 73.33 – – – – – –
p. № 2 4.70 2.29 1.58 20.33 67.69 0.51 0.26
Na, S,
Cl, K,
Ca
Integral
element
compos.
0.05 21.42 1.71 75.62 – 1.20 – –
Integral
element
compos.
2.75 5.23 6.73 62.82 – 1.75 15.11 Cr, Ni
M.K. KYLYSHKANOV
ФІП ФИП PSE, 2007, т. 5, № 3-4, vol. 5, No. 3-4152
activation of mass transfer processes for elements
composing the surface coating layer (Ti, N, C).
Fig. 2a shows RBS energy spectra measured for
TiN/Al2O3/steel samples for two various energies
(the initial energy being 0.8 MeV and 1.5 MeV).
As one can see from these spectra, in the case of
low energy an analyzing ion beam did not allow
us to divide the contributions from TiN and Al2O3
spectra due to essentially thick Al2O3 layer. Using
RBS spectra and the Simnra program we cal-
culated the element distribution profiles for the
coatings which were irradiated with 760 W/cm2
power density (fig. 2b) and (760 +1340) W/cm2
(fig. 2c). The obtained experimental results show
that high current electron beam irradiation with-
out visible melting of the coating and subsequent
increase in the power density to 35 J/cm2 resulted
in a smoothing of the titanium concentration
profile almost to 5 µm. This feature is related to
titanium diffusion to the sample bulk (as well as
to the limits of RBS sensitivity – the least con-
centration boundary) The spectra show that alu-
minum penetrated into the TiN film and forma-
tion of a AlTi compound was possible, as is con-
firmed by the same behavior of Al and Ti at the
depth 2.5 to 4 µm. It was not the case when the
energy density was significantly lower.
Additionally, if one applies the known ratio
in count intensities (when a step was apparent in
the spectra), one can evaluate the stoichiometry
of the assumed compound, which was close to
Al50Ti50. To determine the degree of uniformity
of the material chemical composition, we pre-
pared cross-sections of TiN/Al2O3 coatings. Ac-
cording to [5] a solution of HCl acid etched va-
rious inclusions for 5 minutes remaining the alu-
minum oxide stable.
The photo of the cross-section presented in
fig. 3a shows non-uniformely distributed dark
inclusions. We relate these inclusions in the near
surface and central parts to pores occurring in
the coating structure. The α-phase of aluminum
oxide has a high hardness and a low ability to
deformation under normal conditions and the-
refore was badly polished.
Closer to the contact region with the substrate
the concentration of those dark inclusions in-
creased. We consider that the changes in the ref-
lexive ability of this region were a consequence
of etching off the substrate elements in the steel
contact region with the aluminum oxide powder.
The conclusion that most of dark inclusions are
pores is confirmed by results of etching of TiN/
Al2O3 coatings, which were melted by HCEB at
1340 W/cm2 power density. Fig. 3b shows the
cross- section of one of the regions of such coa-
tings. Dark inclusions are practically absent in
the near surface and the central part of this region.
It follows that the action of heat field of the
electron beam allows one to seal the powder
coatings. Strong etching of the transition region
confirms the formation of strong bonds between
the corundum powder and the metallic base.
Results of X-ray structure analysis show a variety
of coating phase composition after melting by
the electron beam [2]. Aluminum oxide is a uni-
que material in its physical and chemical pro-
perties and standard agents do not affect it [5].
Therefore under usual conditions we set a pro-
blem non to etch some concrete phases Al2O3 in
a) b) c)
Fig. 2. a) Energy spectra of ion back-scattering measured for hybrid coatings (TiN/Al2O3/steel) taken in HCEB-irradiated region. The energy of
incident ions was respectively: 1.5 MeV (a top curve, irradiation density of the electron beam was (760 + 1340) Wt/cm2), 0.8MeV (a lower
curve, HCEB irradiation density was 760 Wt/cm2); Element profiles taken from RBS spectra with ion energy 1.5 MeV for the hybrid coating
after HCEB irradiation (b)– powder density of 760 Wt/cm2, c) – powder density of (760 + 1340) Wt/cm2).
PROPERTIES OF HYBRID TiN/Al2O3 COATINGS USING ELECTRON BEAM MELTING
ФІП ФИП PSE, 2007, т. 5, № 3-4, vol. 5, No. 3-4 153
the given sublayer, but tried to change their color.
Photos obtained after cross sectioning of these
coatings were similar (fig. 3c).
Taking into account the reference data [5] and
the obtained photos, we now can say that the
matrix of the sublayer of aluminum oxide powder
is formed by α-phase (domination of grey and
dark grey colors) and a mixture of metastable
modification of the given material. We would
like to note that a trigonal structure of aluminum
oxide is composed in most cases of small grains,
which are evidently seen on photos with 4000
magnification. So it is difficult to see the grain
structure on these photos, and the biggest
inclusions which we relate to Al2O3 α-phase are
marked by arrows.
Corresponding data on the sample corrosion
after their treatment in sulphuric acid solution
0.5 M under temperature of environment are
presented in tabl. 2.
The corrosion potential in the case of steel
samples without coating was – 445 mV. It
essentially decreased in the case of samples with
coatings. The decrease in corrosion potential and
passivation current density in the case of samples
with coatings indicates an increase in their
corrosion resistance due to a protecting effect of
the deposited layer. Improvements were more
evident in the case of samples which were
subjected to HCEB treatment because of an inner
diffusion of the titanium nitride layer. The
behavior of samples with coating in HCl solution
was almost the same in the sulphuric acid
solution – samples demonstrated lower corrosion
resistance. Qualitative evaluation of SEM data
for the samples which were subjected to strong
corrosion demonstrated that the electrochemical
treatment did not induce essential deviations in
samples.
CONCLUSIONS
The studies of element composition of
TiN/Al2O3 coatings demonstrated that titanium,
nitrogen, carbon, oxygen and aluminum are their
basic composing elements. Melting of the surface
by concentrated energy flows stimulated mass
transfer processes. We observed a saturation of
near surface regions by aluminum and oxygen
ions and a simultaneous penetration of titanium
and nitrogen ions in to the coating bulk. Electron
beam annealing of the surface provided a uniform
redistribution of titanium ions and a partial mel-
ting of non-uniformities in the surface morpho-
logy.
Plasma detonation techniques can be succes-
sfully utilized for deposition of a composite and
hybrid coatings on metallic surfaces. A high cur-
rent electron beam treatment enhanced the cor-
rosion resistance of TiN/Al2O3 coatings.
ACKNOWLEDGMENTS
This work was funded by the NATO Linkage
Grant PST 978157.
a)
b)
c)
Fig. 3. Optical photos of transversal cross-sections of
TiN/Al2O3 coatings, which were melted by HCEB with
the following power densities: a) – 180 Wt/cm2;
b) – (760 + 1340) Wt/cm2; c) – (760 + 960) Wt/cm2.
Sample
Ecorr,
(mV)
icorr,
(mA)
ipass,
(mA)
Epass,
(mV)
Erep,
(mV)
TiN/Al2O3+HCEB –410 2.5 0.7 1022 1066
TiN/Al2O3 –330 11.9 –5.0 860 870
Steel –445 4.5 1.3 1022 1023
Table 2
Results of Electrochemical Studies
M.K. KYLYSHKANOV
ФІП ФИП PSE, 2007, т. 5, № 3-4, vol. 5, No. 3-4154
REFERENCES
1. Borisova A.L., Adeeva L.I., Sladkova V.N.
Automatic welding. – 1997. – № 9. – P. 26-32.
2. Pogrebnjak A.D., Ponarjadov V.V., Kravchenko
Yu.A., Rusimov Ch.M. Physical engineering of
surface. – 2003. – Vol. 1, № 3-4. – P. 210-236.
3. Rykalin N.I., Uglov A.A., Anischenko L.M.
High-temperature termophysical processes. – M.:
Nauka, 1985. – 496 p.
4. Kikoin I.K. Tables of physical sizes. – M.: Аto-
mizdat, 1985. – 1008 p.
5. Baranova L.V., Demina E.L. Metalographical
etching of metals and alloys: the Directory. – M.:
Metallurgija, 1986. – 256 p.
МОДИФІКАЦІЯ ВЛАСТИВОСТЕЙ
ГІБРИДНИХ ПОКРИТТІВ
НА ОСНОВІ TiN/Al2O3
М.К. Килишканов
Представлено нові експериментальні результати
досліджень фазового складу гібридних покриттів
TiN/Al2O3, осаджених на підкладинку з нержаві-
ючої сталі типу AISI 321 комбінованим способом.
Показано, що в процесі кристалізації порошку
Al2O3 на підкладинці формуються зародки його
γ-фази і метастабільних модифікацій. Вакуумно-
дугове осадження нітриду титана на підшар Сr
або порошку корунду дозволяє сформувати плів-
ку, матриця якої складається з ГЦК-TiN з доміш-
кою його тетрагональної модифікації ε-TiN. Знай-
дено режими оплавлення поверхні низькоенерге-
тичним потужнострумовим електронним пучком
(НСЕП), що дозволяють активувати ряд полімор-
фних перетворень типу γ-, β-, δ-, θ → α-Al2O3 і
ε-TiN → TiN і сформувати покриття з α-фази
корунду і кубічної модифікації TiN.
МОДИФИКАЦИЯ СВОЙСТВ
ГИБРИДНЫХ ПОКРЫТИЙ
НА ОСНОВЕ TiN/Al2O3
М.К. Кылышканов
Представлены новые экспериментальные резуль-
таты исследований фазового состава гибридных
покрытий TiN/Al2O3, осажденных на подложку
из нержавеющей стали типа AISI 321 комбиниро-
ванным способом. Показано, что в процессе крис-
таллизации порошка Al2O3 на подложке форми-
руются зародыши его γ-фазы и метастабильных
модификаций. Вакуумно-дуговое осаждение ни-
трида титана на подслой Сr или порошка корунда
позволяет сформировать пленку, матрица которой
состоит из ГЦК-TiN с примесью его тетрагональ-
ной модификации ε-TiN. Найдены режимы опла-
вления поверхности низкоэнергетическим силь-
ноточным электронным пучком (НСЭП), позво-
ляющие активировать ряд полиморфных превра-
щений типа γ-, β-, δ-, θ → α-Al2O3 и ε-TiN → TiN
и сформировать покрытие из α-фазы корунда и
кубической модификации TiN.
PROPERTIES OF HYBRID TiN/Al2O3 COATINGS USING ELECTRON BEAM MELTING
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