Dense, with good adhesion to the substrate, hard, wear-resistant coatings from the powder of Al2O3 were
obtained on the surface of the steel (STE255) by using the cumulative-detonation device. The results of investigations
of the structure and physico-mechanical properties of the coatings by using scanning, optical microscopy,
X-ray phase analysis, microhardness and tribological tests are presented. It was found that optimization
of plasma spraying to helps reduce the porosity of coatings of Al2O3 less than 1 % and to increase the hardness
of them to 1250 HV0.3. The tribological investigations have shown that the coatings of Al2O3 significantly increase
the wear resistance of the sample STE255 and provide a low ability to wear out the coating.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3546

Arseenko, M.Yu.

Kolisnishenko, O.V.

Kovaleva, M.G.

Prozorova, M.S.

Tyurin, Yu.N.

SocioEconomic Challenges Journal (Sumy State University)

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE NANOMATERIALS: APPLICATIONS AND PROPERTIES 
Vol. 1 No 4, 04FCNF05(4pp) (2012) 
 
 
2304-1862/2012/1(4)04FCNF05(4) 04FCNF05-1  2012 Sumy State University 
Structure and the Physico-Mechanical Properties of the Ceramic Coatings Obtained by the 
Cumulative -Detonation Device 
 
M.S. Prozorova1,*, M.G. Kovaleva1, M.Yu. Arseenko1, Yu.N. Tyurin2,†, O.V. Kolisnishenko2 
 
1 Belgorod State University, 85, Pobedy Str., 308015 Belgorod, Russia 
2 Paton Electric Welding Institute NANU, 11, Bozhenko, 03650 Kyiv, Ukraine 
 
(Received 16 June 2012; published online 22 August 2012) 
 
Dense, with good adhesion to the substrate, hard, wear-resistant coatings from the powder of Al2O3 were 
obtained on the surface of the steel (STE255) by using the cumulative-detonation device. The results of inves-
tigations of the structure and physico-mechanical properties of the coatings by using scanning, optical micros-
copy, X-ray phase analysis, microhardness and tribological tests are presented. It was found that optimization 
of plasma spraying to helps reduce the porosity of coatings of Al2O3 less than 1 % and to increase the hardness 
of them to 1250 HV0.3. The tribological investigations have shown that the coatings of Al2O3 significantly in-
crease the wear resistance of the sample STE255 and provide a low ability to wear out the coating. 
 
Keywords: Aluminum oxide, Cumulative-detonation technology, Microhardness, Wear resistance. 
 
  PACS numbers: 68.37.Hk, 68.37.Lp, 68.37.Yz, 68.47.De 
 
 
                                                          
* prozorova@bsu.edu.ru 
† ytyurin@i.com.ua 
1. INTRODUCTION 
 
The ceramic coatings from the powder of Al2O3 are 
usually used to protect the details of which work in the 
hard conditions. They show a high resistance to corro-
sive and oxidizing environments and provide protection 
for details of which work at high temperatures. In addi-
tion, powders based on aluminum oxide have a low val-
ue, which determines the cost-effectiveness of their ap-
plication. A new direction in this area is modification of 
surface by plasma-detonation technology that allows 
obtaining the ceramic coatings with a definite composi-
tion and thickness of reduction of the cost, which de-
termines the cost-effectiveness of their application. 
Plasma-detonation technology is based on the use of 
pulsed plasma jets, accelerated by the electromagnetic 
field up to speed 5000...8000 m/s [1]. All this makes it 
possible to obtain high quality coatings of ceramic and 
metal on metal substrates [2]. The aim of this work was 
to study the structure and the physical and mechanical 
properties of high-quality coatings of Al2O3 obtained by 
detonation-cumulative device. 
 
2. METHODS OF SAMPLE MANUFACTURING 
AND ANALYSIS 
 
The cumulative-detonation technology and equip-
ment is created for deposition of nanocomposite powder 
coatings on samples. The device provides a high velocity 
of the powder materials (>2000 mm/min) without its 
overheating. Productivity was 0.72÷1 kg/hour, gas mix-
ture consumption (С3Н8+О2) – 5.08 m3/hour, frequency – 
20 Hz, the nozzle section to a specimen - 60 µm. Powder 
of Al2O3 (99.5%) with fraction 5.50 -62 μm was used (see. 
Fig. 1). Specimens of steel STE255 were used as а sub-
strates. A uniform coating ~ 200 µm thick was deposited 
on the specimen’s surface. 
Morphological and compositional characterization of 
powder of Al2O3 and surface of ceramic coatings were 
performed by electron ion microscope Quanta 600 FEG 
equipped with integrated microanalysis system Pegasus 
2000 (SEM-EDS). The microhardness of coatings was 
determined on transverse sections of system "coat-
ing/substrate" by an automatic analysis system micro-
hardness DM-8 according to the method of micro-
Vickers. X-ray diffraction studies of coatings were per-
formed on a diffractometer ARL X'TRA company Ther-
mo Scientific. 
The evaluation of wear resistance of coatings was 
carried out by the methods of tribometer using the an 
automated machine friction (Tribometer, CSM Instru-
ments, Switzerland) under the standard scheme of test 
"disc/ball" on the air under a load of 6 N. The porosity of 
the coatings from the powder of Al2O3 was determined 
by metallographic method using an optical inverted mi-
croscope Olympus GX51. 
 
 
 
Fig. 1 – Morphology and elemental composition (energy dis-
persive spectrum) of Al2O3 powder (SEM) 
 
3. RESULTS AND DISCUSSION 
 
Electron microscopic investigation of transverse sec-
tions of the «coating/substrate» has shown that the coat-
ing of powder of Al2O3 characterized by the alternation 
 M.S. PROZOROVA, M.G. KOVALEVA, M.YU. ARSEENKO, ET AL. PROC. NAP 1, 04FCNF05 (2012) 
 
 
04FCNF05-2 
of compressed flakes and deformed discrete particles of 
the oxide. Coating formed by stacking a set of deformed 
coherent particles with different temperature, velocity 
and mass (see. Fig. 2). 
 
 
 
Fig. 2 – Microstructure of transverse sections of the sample 
with coating of Al2O3 
 
Thick coatings with good adhesion to the substrate 
and the low porosity less than 1% obtained by plasma-
detonation device from the alumina powder (see. 
Fig. 2). The quality of coatings was achieved by the 
presence of α-Al2O3, its share to 67% (see. Fig. 3). Anal-
ysis of the structural features of the interface "coat-
ing/substrate" has shown that the plasma-detonation 
powder coatings have three visually distinguishable 
zones (substrate, transition layer and main coating) 
(see. Fig. 4a). It should be noted that the elemental 
composition of the transition region from point to point 
remains almost unchanged. The main components of 
the matrix are the Al and O, and their concentration at 
different points changes insignificantly. Impurity ele-
ments in the transition region of the substrate are the 
elements of the substrate Fe, Cr, C, Na and Si. The 
presence of impurity elements in the coatings in the 
transition region has been caused by mixing of detona-
tion gases, air and sputtered particles of the substrate. 
Analysis of the structure of the interface "coat-
ing/substrate" after etching has shown that the coating 
has four visually distinct zones (see. Fig. 4a). Content 
of aluminum in the transition region in the point 2 was 
76%, in the point 3 - 49% (see. Table 1). Therefore, the 
material of boundary was a mix of elements of the sub-
strate and coating. 
 
 
a 
 
 
b 
 
Fig. 4 – Structure of Al2O3 coating (SEM) 
 
 
 
 
Fig. 3 – Results of X-ray analysis of Al2O3 coating 
 
 STRUCTURE AND THE PHYSICO-MECHANICAL PROPERTIES… PROC. NAP 1, 04FCNF05 (2012) 
 
 
04FCNF05-3 
Table 1 – The elemental composition of the material of the boundary and sample of the surface (Fig. 4a) 
 
Point Content of the elements, at.% 
Al O Fe С Si 
1 54.02 45.98 - - - 
2 76.13 22.48 - 0.96 0.43 
3 49.99 24.21 20.33 3.98 1.16 
4 0.20 4.37 87.52 5.65 0.62 
 
At the boundary between the transition zone and 
the main coating (point 3) the concentration of atoms of 
aluminum was about 50 wt.%, and oxygen ~24 wt.%. It 
was established that the content of iron in the transi-
ent region is 20 wt.% what can be attributed to its mass 
transfer from the substrate. 
It was found the presence of iron, metallic alumi-
num and intermetallic AlFe on the border between the 
coating and substrate. This favors the relaxation of 
stresses arise during the deposition of coatings [3]. 
Therefore, the iron should be considered as an impuri-
ty, which is a favorable effect on the mechanical prop-
erties of coatings. 
The content of the carbon in the ceramic coating of 
the Al2O3 is principled. The presence of significant 
amounts of carbon in the coating leads to a deteriora-
tion of service characteristics. For example, the pres-
ence of carbon reduces the density of the coating and 
the formation of pores, which significantly decreases 
the corrosion resistance. Also, the presence of carbon in 
the coatings affects the cohesion between layers of 
sprayed coatings, as well as the adhesion between the 
coating and steel substrate. The interaction of carbon 
with iron formed brittle phase, which leads to the ap-
pearance of cracks on the boundary. 
Thus, to improve the performance properties was 
selected regime of the deposition of the coating in an 
oxidizing atmosphere (with excess oxygen). Oxidizing 
atmosphere also prevented the hydrogenation coatings, 
as it is known that alumina adsorbs hydrogen well in a 
heated state. Thus, the results of microanalysis of the 
transition layer and separate sections covering confirm 
the mixing of the coating material - Al2O3 with the sub-
strate material, indicating that a strong connection of 
the resulting system "coating/substrate" interface. 
The microhardness of coatings was determined 
from transverse sections. It was found that the hard-
ness of coatings Al2O3  was 1500 ± 25 HV0.025, which in-
dicates that the homogeneity of sufficient density but 
adjacent layers of the coating. It should be noted that 
the hardness of the coating of 4.3 higher than the 
hardness of the substrate material STE255 – 
346 ± 5 HV0.025. It should be noted no significant spread 
of values of the microhardness of coatings from point to 
point (see. Fig. 5). This could mean that coatings have 
the phase and structural homogeneity. The microhard-
ness of coating layer is stable and its fluctuations did 
not exceed 5%. The coatings were sufficient plasticity, 
as evidenced by the absence of cracks in the corners of 
the prints at a load of 25 g. Cracks were appeared only 
at a load of 300 g (see. Fig. 6). At a load of 300 g of the 
microhardness values are somewhat lower. This phe-
nomenon is explained by the elastic reduction [4]. 
The microhardness of the substrate of steel STE255 
under the coating was changes to a depth of 200 μm 
from 550 HV0.025 to medium hardness of the substrate 
material -346 HV0.025. The figure 7 demonstrates that 
the microhardness of the substrate decreases by 1.5 
times at a depth of 15 microns from the boundary "coat-
ing/substrate" and reached the minimal value at a 
depth of 180 microns. It means explains the presence of 
work hardening near the boundary with the surface, 
was formed as a result of impact in the process of abra-
sive blasting and coating. 
The microhardness of coating was measured from 
the surface to the substrate gradually decreases from 
the surface of the substrate from 1250 to 900 HV0.3. 
This decrease is due to the mechanism of formation of 
layered coating and heating below the underlying lay-
ers. These conditions are the result of the formation of 
a soft plastic and aluminum oxide phases. 
 
 
 
Fig. 5 – SEM image of microstructure of Al2O3 coating with 
measuring microhardness (HV0.025) 
 
 
 
Fig. 6 – SEM image of microstructure of Al2O3 coating with 
measuring microhardness (HV0.3) 
 
 M.S. PROZOROVA, M.G. KOVALEVA, M.YU. ARSEENKO, ET AL. PROC. NAP 1, 04FCNF05 (2012) 
 
 
04FCNF05-4 
Wear resistance tests performed on air at load of 
6 N, linear speed is 15 cm / sec, the radius of curvature 
of 5 mm of wear, sliding distance of 1200 meters. From 
the data of table 2 shows that the investigated coating 
significantly increases the wear resistance of the sam-
ple STE255, also provides a low ability to wear out the 
coating. 
Investigation of the topology of friction surface 
coating shows that the initial friction coefficient of 
coated steel was 0.038, which may be due to the high 
roughness of the sample. Found that despite the in-
crease in counterface of wear, track wear and tear, 
however, without destroying the coating, which is asso-
ciated with good wear resistance of the coating. 
 
 
Fig. 7 – The microhardness of the substrate 
 
Table 2 – Tribological characteristics 
 
Sample The coefficient of friction (μ) The wear factor, 113 mNm  
initial test counter body (x10-5) sample (x10-5) 
Steel (STE255) 0.204 0.674 0.269 35.36 
Steel/Al2O3 0.038 0.959 1.61 19.39 
 
4. CONCLUSION 
 
Ceramic multifunction dense coatings from the 
powder of Al2O3 were obtained by the cumulative deto-
nation technology. The microhardness of coatings de-
creases smoothly from the surface of the substrate from 
1250 to 900 HV0.3. In spite of the high hardness of the 
coatings, they are sufficient plasticity, which confirms 
the absence of cracks in the corners of indents at a load 
of 25 g. 
Analysis of the transition layer "coating/substrate" 
interface was showed that the layer is well adjacent to 
the substrate. Is formed transition layer, consisting of 
the dissociation products of elements of the substrate 
and the oxide. The hardness of the substrate layer is 
adjacent to the coating, increasing to 550 HV0.025 at a 
hardness of the basis 340 HV0.025. 
Optimization of plasma spraying to helps reduce 
the porosity less than 1 % and to increase the hardness 
of the coating to 1250 HV0.3. When spraying agglomer-
ated powders, micron particles collected from the ce-
ramic coating hardness reaches 1350 HV0.3 using as a 
fuel gas of hydrogen and 1000 HV0.3 using propane. 
 
AKNOWLEDGEMENTS 
 
Work is carried out by Joint Research Center of 
Belgorod State University in the framework of the fed-
eral target program under Grant application 
№ 14.740.11.1017.
 
REFERENCES 
 
1. E. Turunen, T. Varis, S.-P. Hannula, J. Keskinen, 
P. Lintunen, Thermal Spray 2007: Global Coating Solu-
tions, Materials Park (USA, Ohio). 
2. M.A. Riley, A.J. Sturgeon, Thermal Spray 2007: Global 
Coating Solutions, Materials Park (USA, Ohio). 
3. Yu.N. Tyurin, M.A. Zhadkevich., A.D. Pogrebnyak, 
O.V. Kolisnichenko, 6th International Conference "Films 
and coatings" (Russia, St. Petersburg, 2001). 
4. Tests on the microhardness mikrovdavlivaniem (Ed. 
B.V. Mott) (Moscow: Metallurgizdat: 1960). 
5. B. Wielage, A. Wank, H. Pokhmurska, E. Friesen, 
T. Grund, A. Schwenk, Thermal Spray 2007: Global Coat-
ing Solutions, Materials Park (USA, Ohio). 
6. S. Tao, X. Zhou, C. Ding. Thermal Spray 2007: Global 
Coating Solutions, Materials Park (USA, Ohio). 
7. E. Turunen, U. Kanerva, T. Varis, J. Knuuttila, J. Leivo, 
J. Silvonen. Thermal Spray 2007: Global Coating Solu-
tions, Materials Park (USA, Ohio). 
8. Yu.N. Tyurin, A.D. Pogrebnjak, Surf. Coаt. Tech. 111, 269 
(1999). 
 


English

Structure and the Physico-Mechanical Properties of the Ceramic Coatings Obtained by the Cumulative -Detonation Device

Electronic Sumy State University Institutional Repository

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE NANOMATERIALS: APPLICATIONS AND PROPERTIES Vol. 1 No 4, 04FCNF05(4pp) (2012)   2304-1862/2012/1(4)04FCNF05(4) 04FCNF05-1  2012 Sumy State University Structure and the Physico-Mechanical Properties of the Ceramic Coatings Obtained by the Cumulative -Detonation Device  M.S. Prozorova1,*, M.G. Kovaleva1, M.Yu. Arseenko1, Yu.N. Tyurin2,†, O.V. Kolisnishenko2  1 Belgorod State University, 85, Pobedy Str., 308015 Belgorod, Russia 2 Paton Electric Welding Institute NANU, 11, Bozhenko, 03650 Kyiv, Ukraine  (Received 16 June 2012; published online 22 August 2012)  Dense, with good adhesion to the substrate, hard, wear-resistant coatings from the powder of Al2O3 were obtained on the surface of the steel (STE255) by using the cumulative-detonation device. The results of inves-tigations of the structure and physico-mechanical properties of the coatings by using scanning, optical micros-copy, X-ray phase analysis, microhardness and tribological tests are presented. It was found that optimization of plasma spraying to helps reduce the porosity of coatings of Al2O3 less than 1 % and to increase the hardness of them to 1250 HV0.3. The tribological investigations have shown that the coatings of Al2O3 significantly in-crease the wear resistance of the sample STE255 and provide a low ability to wear out the coating.  Keywords: Aluminum oxide, Cumulative-detonation technology, Microhardness, Wear resistance.    PACS numbers: 68.37.Hk, 68.37.Lp, 68.37.Yz, 68.47.De                                                             * prozorova@bsu.edu.ru † ytyurin@i.com.ua 1. INTRODUCTION  The ceramic coatings from the powder of Al2O3 are usually used to protect the details of which work in the hard conditions. They show a high resistance to corro-sive and oxidizing environments and provide protection for details of which work at high temperatures. In addi-tion, powders based on aluminum oxide have a low val-ue, which determines the cost-effectiveness of their ap-plication. A new direction in this area is modification of surface by plasma-detonation technology that allows obtaining the ceramic coatings with a definite composi-tion and thickness of reduction of the cost, which de-termines the cost-effectiveness of their application. Plasma-detonation technology is based on the use of pulsed plasma jets, accelerated by the electromagnetic field up to speed 5000...8000 m/s [1]. All this makes it possible to obtain high quality coatings of ceramic and metal on metal substrates [2]. The aim of this work was to study the structure and the physical and mechanical properties of high-quality coatings of Al2O3 obtained by detonation-cumulative device.  2. METHODS OF SAMPLE MANUFACTURING AND ANALYSIS  The cumulative-detonation technology and equip-ment is created for deposition of nanocomposite powder coatings on samples. The device provides a high velocity of the powder materials (>2000 mm/min) without its overheating. Productivity was 0.72÷1 kg/hour, gas mix-ture consumption (С3Н8+О2) – 5.08 m3/hour, frequency – 20 Hz, the nozzle section to a specimen - 60 µm. Powder of Al2O3 (99.5%) with fraction 5.50 -62 μm was used (see. Fig. 1). Specimens of steel STE255 were used as а sub-strates. A uniform coating ~ 200 µm thick was deposited on the specimen’s surface. Morphological and compositional characterization of powder of Al2O3 and surface of ceramic coatings were performed by electron ion microscope Quanta 600 FEG equipped with integrated microanalysis system Pegasus 2000 (SEM-EDS). The microhardness of coatings was determined on transverse sections of system "coat-ing/substrate" by an automatic analysis system micro-hardness DM-8 according to the method of micro-Vickers. X-ray diffraction studies of coatings were per-formed on a diffractometer ARL X'TRA company Ther-mo Scientific. The evaluation of wear resistance of coatings was carried out by the methods of tribometer using the an automated machine friction (Tribometer, CSM Instru-ments, Switzerland) under the standard scheme of test "disc/ball" on the air under a load of 6 N. The porosity of the coatings from the powder of Al2O3 was determined by metallographic method using an optical inverted mi-croscope Olympus GX51.    Fig. 1 – Morphology and elemental composition (energy dis-persive spectrum) of Al2O3 powder (SEM)  3. RESULTS AND DISCUSSION  Electron microscopic investigation of transverse sec-tions of the «coating/substrate» has shown that the coat-ing of powder of Al2O3 characterized by the alternation  M.S. PROZOROVA, M.G. KOVALEVA, M.YU. ARSEENKO, ET AL. PROC. NAP 1, 04FCNF05 (2012)   04FCNF05-2 of compressed flakes and deformed discrete particles of the oxide. Coating formed by stacking a set of deformed coherent particles with different temperature, velocity and mass (see. Fig. 2).    Fig. 2 – Microstructure of transverse sections of the sample with coating of Al2O3  Thick coatings with good adhesion to the substrate and the low porosity less than 1% obtained by plasma-detonation device from the alumina powder (see. Fig. 2). The quality of coatings was achieved by the presence of α-Al2O3, its share to 67% (see. Fig. 3). Anal-ysis of the structural features of the interface "coat-ing/substrate" has shown that the plasma-detonation powder coatings have three visually distinguishable zones (substrate, transition layer and main coating) (see. Fig. 4a). It should be noted that the elemental composition of the transition region from point to point remains almost unchanged. The main components of the matrix are the Al and O, and their concentration at different points changes insignificantly. Impurity ele-ments in the transition region of the substrate are the elements of the substrate Fe, Cr, C, Na and Si. The presence of impurity elements in the coatings in the transition region has been caused by mixing of detona-tion gases, air and sputtered particles of the substrate. Analysis of the structure of the interface "coat-ing/substrate" after etching has shown that the coating has four visually distinct zones (see. Fig. 4a). Content of aluminum in the transition region in the point 2 was 76%, in the point 3 - 49% (see. Table 1). Therefore, the material of boundary was a mix of elements of the sub-strate and coating.   a   b  Fig. 4 – Structure of Al2O3 coating (SEM)     Fig. 3 – Results of X-ray analysis of Al2O3 coating   STRUCTURE AND THE PHYSICO-MECHANICAL PROPERTIES… PROC. NAP 1, 04FCNF05 (2012)   04FCNF05-3 Table 1 – The elemental composition of the material of the boundary and sample of the surface (Fig. 4a)  Point Content of the elements, at.% Al O Fe С Si 1 54.02 45.98 - - - 2 76.13 22.48 - 0.96 0.43 3 49.99 24.21 20.33 3.98 1.16 4 0.20 4.37 87.52 5.65 0.62  At the boundary between the transition zone and the main coating (point 3) the concentration of atoms of aluminum was about 50 wt.%, and oxygen ~24 wt.%. It was established that the content of iron in the transi-ent region is 20 wt.% what can be attributed to its mass transfer from the substrate. It was found the presence of iron, metallic alumi-num and intermetallic AlFe on the border between the coating and substrate. This favors the relaxation of stresses arise during the deposition of coatings [3]. Therefore, the iron should be considered as an impuri-ty, which is a favorable effect on the mechanical prop-erties of coatings. The content of the carbon in the ceramic coating of the Al2O3 is principled. The presence of significant amounts of carbon in the coating leads to a deteriora-tion of service characteristics. For example, the pres-ence of carbon reduces the density of the coating and the formation of pores, which significantly decreases the corrosion resistance. Also, the presence of carbon in the coatings affects the cohesion between layers of sprayed coatings, as well as the adhesion between the coating and steel substrate. The interaction of carbon with iron formed brittle phase, which leads to the ap-pearance of cracks on the boundary. Thus, to improve the performance properties was selected regime of the deposition of the coating in an oxidizing atmosphere (with excess oxygen). Oxidizing atmosphere also prevented the hydrogenation coatings, as it is known that alumina adsorbs hydrogen well in a heated state. Thus, the results of microanalysis of the transition layer and separate sections covering confirm the mixing of the coating material - Al2O3 with the sub-strate material, indicating that a strong connection of the resulting system "coating/substrate" interface. The microhardness of coatings was determined from transverse sections. It was found that the hard-ness of coatings Al2O3  was 1500 ± 25 HV0.025, which in-dicates that the homogeneity of sufficient density but adjacent layers of the coating. It should be noted that the hardness of the coating of 4.3 higher than the hardness of the substrate material STE255 – 346 ± 5 HV0.025. It should be noted no significant spread of values of the microhardness of coatings from point to point (see. Fig. 5). This could mean that coatings have the phase and structural homogeneity. The microhard-ness of coating layer is stable and its fluctuations did not exceed 5%. The coatings were sufficient plasticity, as evidenced by the absence of cracks in the corners of the prints at a load of 25 g. Cracks were appeared only at a load of 300 g (see. Fig. 6). At a load of 300 g of the microhardness values are somewhat lower. This phe-nomenon is explained by the elastic reduction [4]. The microhardness of the substrate of steel STE255 under the coating was changes to a depth of 200 μm from 550 HV0.025 to medium hardness of the substrate material -346 HV0.025. The figure 7 demonstrates that the microhardness of the substrate decreases by 1.5 times at a depth of 15 microns from the boundary "coat-ing/substrate" and reached the minimal value at a depth of 180 microns. It means explains the presence of work hardening near the boundary with the surface, was formed as a result of impact in the process of abra-sive blasting and coating. The microhardness of coating was measured from the surface to the substrate gradually decreases from the surface of the substrate from 1250 to 900 HV0.3. This decrease is due to the mechanism of formation of layered coating and heating below the underlying lay-ers. These conditions are the result of the formation of a soft plastic and aluminum oxide phases.    Fig. 5 – SEM image of microstructure of Al2O3 coating with measuring microhardness (HV0.025)    Fig. 6 – SEM image of microstructure of Al2O3 coating with measuring microhardness (HV0.3)   M.S. PROZOROVA, M.G. KOVALEVA, M.YU. ARSEENKO, ET AL. PROC. NAP 1, 04FCNF05 (2012)   04FCNF05-4 Wear resistance tests performed on air at load of 6 N, linear speed is 15 cm / sec, the radius of curvature of 5 mm of wear, sliding distance of 1200 meters. From the data of table 2 shows that the investigated coating significantly increases the wear resistance of the sam-ple STE255, also provides a low ability to wear out the coating. Investigation of the topology of friction surface coating shows that the initial friction coefficient of coated steel was 0.038, which may be due to the high roughness of the sample. Found that despite the in-crease in counterface of wear, track wear and tear, however, without destroying the coating, which is asso-ciated with good wear resistance of the coating.   Fig. 7 – The microhardness of the substrate  Table 2 – Tribological characteristics  Sample The coefficient of friction (μ) The wear factor, 113 mNm  initial test counter body (x10-5) sample (x10-5) Steel (STE255) 0.204 0.674 0.269 35.36 Steel/Al2O3 0.038 0.959 1.61 19.39  4. CONCLUSION  Ceramic multifunction dense coatings from the powder of Al2O3 were obtained by the cumulative deto-nation technology. The microhardness of coatings de-creases smoothly from the surface of the substrate from 1250 to 900 HV0.3. In spite of the high hardness of the coatings, they are sufficient plasticity, which confirms the absence of cracks in the corners of indents at a load of 25 g. Analysis of the transition layer "coating/substrate" interface was showed that the layer is well adjacent to the substrate. Is formed transition layer, consisting of the dissociation products of elements of the substrate and the oxide. The hardness of the substrate layer is adjacent to the coating, increasing to 550 HV0.025 at a hardness of the basis 340 HV0.025. Optimization of plasma spraying to helps reduce the porosity less than 1 % and to increase the hardness of the coating to 1250 HV0.3. When spraying agglomer-ated powders, micron particles collected from the ce-ramic coating hardness reaches 1350 HV0.3 using as a fuel gas of hydrogen and 1000 HV0.3 using propane.  AKNOWLEDGEMENTS  Work is carried out by Joint Research Center of Belgorod State University in the framework of the fed-eral target program under Grant application № 14.740.11.1017. REFERENCES  1. E. Turunen, T. Varis, S.-P. Hannula, J. Keskinen, P. Lintunen, Thermal Spray 2007: Global Coating Solu-tions, Materials Park (USA, Ohio). 2. M.A. Riley, A.J. Sturgeon, Thermal Spray 2007: Global Coating Solutions, Materials Park (USA, Ohio). 3. Yu.N. Tyurin, M.A. Zhadkevich., A.D. Pogrebnyak, O.V. Kolisnichenko, 6th International Conference "Films and coatings" (Russia, St. Petersburg, 2001). 4. Tests on the microhardness mikrovdavlivaniem (Ed. B.V. Mott) (Moscow: Metallurgizdat: 1960). 5. B. Wielage, A. Wank, H. Pokhmurska, E. Friesen, T. Grund, A. Schwenk, Thermal Spray 2007: Global Coat-ing Solutions, Materials Park (USA, Ohio). 6. S. Tao, X. Zhou, C. Ding. Thermal Spray 2007: Global Coating Solutions, Materials Park (USA, Ohio). 7. E. Turunen, U. Kanerva, T. Varis, J. Knuuttila, J. Leivo, J. Silvonen. Thermal Spray 2007: Global Coating Solu-tions, Materials Park (USA, Ohio). 8. Yu.N. Tyurin, A.D. Pogrebnjak, Surf. Coаt. Tech. 111, 269 (1999).  

Dense, with good adhesion to the substrate, hard, wear-resistant coatings from the powder of Al2O3 were obtained on the surface of the steel (STE255) by using the cumulative-detonation device. The results of investigations of the structure and physico-mechanical properties of the coatings by using scanning, optical microscopy, X-ray phase analysis, microhardness and tribological tests are presented. It was found that optimization of plasma spraying to helps reduce the porosity of coatings of Al2O3 less than 1 % and to increase the hardness of them to 1250 HV0.3. The tribological investigations have shown that the coatings of Al2O3 significantly increase the wear resistance of the sample STE255 and provide a low ability to wear out the coatin

Prozorova, M. S.

Kovaleva, M. G.

Arseenko, M. Yu.

Tyurin, Yu. N.

Kolisnishenko, O. V.

DSpace at Belgorod State University

Structure and the physico-mechanical properties of the ceramic coatings obtained by the cumulative -detonation device

http://dspace.bsu.edu.ru/bitstream/123456789/15683/1/Prozorova_Structure_12.pdf

Structure and the Physico-Mechanical Properties of the Ceramic Coatings Obtained by the Cumulative -Detonation Device

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SocioEconomic Challenges Journal (Sumy State University)

Electronic Sumy State University Institutional Repository

DSpace at Belgorod State University