The effect of substrate bias on the structural-phase and elastic stress-strained state during the formation
of vacuum-arc deposited nanostructural coatings of the Mo–N system has been studied. An increase
in the bias potential leads to (i) predominant [111] orientation of the growing molybdenum nitride
crystals with a NaCl-type cubic lattice (γ-Mo2N phase) and (ii) the appearance of a second phase with a
body-centered cubic crystal lattice that is characteristic of pure molybdenum. The elastically strained
(stressed) state of the coating is determined not only by the conditions of deposition, but also by the mechanical
properties of a substrate. In order to provide for formation of coatings in a high-elastic-strained
(stressed) state, it is necessary to deposit coatings onto substrates with high elastic modulus, which prevent
metal flow at the interface.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3480

Andreev, A.A.

Filchikov, V.Ye.

Grigorev, S.N.

Sobol, O.V.

Stolbovoy, V.A.

Volosova, M.A.

Electronic Sumy State University Institutional Repository

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE NANOMATERIALS: APPLICATIONS AND PROPERTIES Vol. 1 No 2, 02NFC04(2pp) (2012)   2304-1862/2012/1(2)02NFC04(2) 02NFC04-1  2012 Sumy State University Structural-phase and Strained State of Vacuum-ARC Mo-N Coatings  А.А. Andreev1,*, S. N. Grigorev2,†, O.V. Sobol`3,‡, M.А. Volosova2, V.А. Stolbovoy1, V.Ye. Fil`chikov3  1 National Scientific Centre «KhPTI», 1, Akademicheskaya St., 61108, Kharkov, Ukraine 2 Moscow State Technological University “STANKIN”, 3a Vadkovsky per., 127055, Moscow, Russia  3 National Technical University “KhPI”, 21, Frunze St., 61002, Kharkov, Ukraine  (Received 13 March 2012; published online16 August 2012)  The effect of substrate bias on the structural-phase and elastic stress-strained state during the for-mation of vacuum-arc deposited nanostructural coatings of the Mo–N system has been studied. An in-crease in the bias potential leads to (i) predominant [111] orientation of the growing molybdenum nitride crystals with a NaCl-type cubic lattice (γ-Mo2N phase) and (ii) the appearance of a second phase with a body-centered cubic crystal lattice that is characteristic of pure molybdenum. The elastically strained (stressed) state of the coating is determined not only by the conditions of deposition, but also by the me-chanical properties of a substrate. In order to provide for formation of coatings in a high-elastic-strained (stressed) state, it is necessary to deposit coatings onto substrates with high elastic modulus, which pre-vent metal flow at the interface.  Keywords: Vacuum-arc coating, Mo–N system, Negative bias, Structural-phase state, Predominant orien-tation, Elastic-strained (stressed) state.   PACS numbers: 81.07.Bc , 61.05.cf ; 62.25. – g ______________ * aandreev@kipt.kharkov.ua † science@stankin.ru  ‡ sobol@kpi.kharkov.ua   1. INTRODUCTION  At the present time, there is a distinct lack of in-formation on the influence of vacuum-plasma parame-ters process of obtaining the most commonly used ni-tride coatings deposited in a reactive environment on the formation of phase composition, structure and strained state. The high sensitivity of the state of coating system Mo-N to the conditions of deposition [1-3] led to the need of studying of the influence of conditions of vacu-um-arc deposition on the phase composition, structure and strained state of the formed material.  2. METHODS OF SAMPIE MANUFACTURING AND ANALYSIS  Coatings were obtained by using vacuum-arc appa-ratus, "Bulat-6". Vaporized material is pure vacuum melted molybdenum. Deposition parameters: arc current I  105 and 160 A, a constant substrate potential -5V ("floating" potential) 40 V and 200 V, the nitrogen pressure during deposition was 0.03 Pa and 0.2 Pa. Pol-ished substrates made of stainless steel 12Х18Н9Т, nick-el (plate 4 mm thick), copper (plate thickness of 5 mm and a foil thickness of 0.2 mm) were used for the deposi-tion. After pumping the vacuum chamber to a pressure of PN  1 • 10-3 Pa a negative bias of 1000 V was applied to a substrate and with an arc current of 105 A cleaning and activation of the surface by means of molybdenum ion bombardment was held for (3 ... 4) minutes.  3. RESULTS AND DISCUSSION   The phase composition by X-ray diffraction (DRON -3M, the emission of Cu-Kα) showed that in low nitrogen pressure of (0.03…0.04) Pa vacuum-arc coatings consist of α-Mo with lattice parameter 0.3152 nm, which have a columnar structure and hardness of (3.5…5) GPa. With increasing of pressure to more then 0.04 Pa traces of high-temperature -Mo2N phase and low-temperature -Mo2N phase appear in the coating com-position. Their content increases with increasing pres-sure.  Higher pressures PN  (0,06 ... 0.2) Pa lead to the formation of molybdenum nitride coatings Mo2N of two modifications which are identical to the products of interaction of molybdenum with nitrogen according to the equilibrium phase diagram. Along with the high-temperature -Mo2N phase with a cubic lattice, low-temperature phase -Mo2N with a tetragonal lattice is revealed, its content increases with increasing the dep-osition rate. At a pressure of about 0.07 Pa hardness of coatings reaches its maximum (45 ... 55) GPa. In the coatings with higher hardness the average size of grains (crystallites) is about 15 nm at a value of mi-crostrain 0.4%. Typical X-ray diffraction spectra of the coatings Mo-N, obtained at pressures of 0.06 ... 0.2 Pa and a low bias ( 40 V) are shown in Fig. 1. If we examine the influence of the thickness of coatings on the appearance of preferred orientation of growth of crystallites -Mo2N phase with a cubic lattice (structural type NaCl), then under small thickness ((0.7 – 1.1) microns) texture with the growth axis perpendicular to the surface [100] is formed. This becomes apparent in the relative intensity amplification of diffraction peaks from the planes (200) and (400). In the thick coatings with the thickness of (4.5 – 7) microns the preferred orientation of crystallites with the plane (311) parallel to the growth surface is formed, i.e. with  А.А. ANDREEV, S. N. GRIGOREV, O.V. SOBOL, ET AL. PROC. NAP 1, 02NFC04(2012)   02NFC04-2 the texture axis [311]. It should be noted that the texture formed in the -Mo2N phase is a weak texture, as width at half maximum while ψ-scanning of this texture was 30° (  > 30°) for a plane (311).    Fig. 1 – X-ray diffraction spectra of Mo-N coatings with low potential for bias ( 40 V): 1 – PN  0,06 Pa. 2 – PN  0,2 Pa  In case of a large potential bias ( 200V) secondary sputtering of the nitrogen atoms from the surface leads to the change of phase composition and to appearance of intense diffraction peaks of the solid solution of ni-trogen in molybdenum with a bcc-lattice.  4. CONCIUSION  An increase in the bias potential leads to predomi-nant [111] orientation of the growing molybdenum ni-tride crystals with a NaCl-type cubic lattice ( -Mo2N phase) and the appearance of a second phase with a body-centered cubic crystal lattice that is characteristic of pure molybdenum.  The elastically strained (stressed) state of the coat-ing is determined not only by the conditions of deposi-tion, but also by the mechanical properties of a sub-strate. Elastic macrostress-deformed state of coatings, determined by the method of multiple inclined surveys, have been contracting. The  magnitude of macrodefor-mation for coatings with the greatest firmness reached high values 1.9 ... 2.0%.    REFERENCES  1. A.A. Andreev, L.P. Sablev, S.N. Grigor`ev, Vacuum-Arc Deposited Coatings (Institute of Physics and Technology, Kharkov, 2010).  2. A.N. Azarenkov, O.V. Sobol ,` A.D. Pogrebnyak, V.M. Beresnev, Engeineering of Vacuum Deposited Coatings (Kharkov National University, Kharkov, 2011). 3. A.P. Shpak, O.I. Nakonechnaya, Yu.A. Kunits`kii, O.V. Sobol`, Mechanical Properties of Titanium-based Coatings (Institute of Metal Physics: Kiev: 2005).  

Structural-phase and Strained State of Vacuum-ARC Mo-N Coatings

SocioEconomic Challenges Journal (Sumy State University)

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE NANOMATERIALS: APPLICATIONS AND PROPERTIES 
Vol. 1 No 2, 02NFC04(2pp) (2012) 
 
 
2304-1862/2012/1(2)02NFC04(2) 02NFC04-1  2012 Sumy State University 
Structural-phase and Strained State of Vacuum-ARC Mo-N Coatings 
 
А.А. Andreev1,*, S. N. Grigorev2,†, O.V. Sobol`3,‡, M.А. Volosova2, V.А. Stolbovoy1, V.Ye. Fil`chikov3 
 
1 National Scientific Centre «KhPTI», 1, Akademicheskaya St., 61108, Kharkov, Ukraine 
2 Moscow State Technological University “STANKIN”, 3a Vadkovsky per., 127055, Moscow, Russia  
3 National Technical University “KhPI”, 21, Frunze St., 61002, Kharkov, Ukraine 
 
(Received 13 March 2012; published online16 August 2012) 
 
The effect of substrate bias on the structural-phase and elastic stress-strained state during the for-
mation of vacuum-arc deposited nanostructural coatings of the Mo–N system has been studied. An in-
crease in the bias potential leads to (i) predominant [111] orientation of the growing molybdenum nitride 
crystals with a NaCl-type cubic lattice (γ-Mo2N phase) and (ii) the appearance of a second phase with a 
body-centered cubic crystal lattice that is characteristic of pure molybdenum. The elastically strained 
(stressed) state of the coating is determined not only by the conditions of deposition, but also by the me-
chanical properties of a substrate. In order to provide for formation of coatings in a high-elastic-strained 
(stressed) state, it is necessary to deposit coatings onto substrates with high elastic modulus, which pre-
vent metal flow at the interface. 
 
Keywords: Vacuum-arc coating, Mo–N system, Negative bias, Structural-phase state, Predominant orien-
tation, Elastic-strained (stressed) state. 
 
 PACS numbers: 81.07.Bc , 61.05.cf ; 62.25. – g 
______________ 
* aandreev@kipt.kharkov.ua 
† science@stankin.ru  
‡ sobol@kpi.kharkov.ua 
 
 
1. INTRODUCTION 
 
At the present time, there is a distinct lack of in-
formation on the influence of vacuum-plasma parame-
ters process of obtaining the most commonly used ni-
tride coatings deposited in a reactive environment on 
the formation of phase composition, structure and 
strained state. 
The high sensitivity of the state of coating system 
Mo-N to the conditions of deposition [1-3] led to the 
need of studying of the influence of conditions of vacu-
um-arc deposition on the phase composition, structure 
and strained state of the formed material. 
 
2. METHODS OF SAMPIE MANUFACTURING 
AND ANALYSIS 
 
Coatings were obtained by using vacuum-arc appa-
ratus, "Bulat-6". Vaporized material is pure vacuum 
melted molybdenum. Deposition parameters: arc current 
I  105 and 160 A, a constant substrate potential -5V 
("floating" potential) 40 V and 200 V, the nitrogen 
pressure during deposition was 0.03 Pa and 0.2 Pa. Pol-
ished substrates made of stainless steel 12Х18Н9Т, nick-
el (plate 4 mm thick), copper (plate thickness of 5 mm 
and a foil thickness of 0.2 mm) were used for the deposi-
tion. After pumping the vacuum chamber to a pressure of 
PN  1 • 10-3 Pa a negative bias of 1000 V was applied to 
a substrate and with an arc current of 105 A cleaning and 
activation of the surface by means of molybdenum ion 
bombardment was held for (3 ... 4) minutes. 
 
3. RESULTS AND DISCUSSION  
 
The phase composition by X-ray diffraction (DRON -
3M, the emission of Cu-Kα) showed that in low nitrogen 
pressure of (0.03…0.04) Pa vacuum-arc coatings consist 
of α-Mo with lattice parameter 0.3152 nm, which have 
a columnar structure and hardness of (3.5…5) GPa. 
With increasing of pressure to more then 0.04 Pa traces 
of high-temperature -Mo2N phase and low-
temperature -Mo2N phase appear in the coating com-
position. Their content increases with increasing pres-
sure.  
Higher pressures PN  (0,06 ... 0.2) Pa lead to the 
formation of molybdenum nitride coatings Mo2N of two 
modifications which are identical to the products of 
interaction of molybdenum with nitrogen according to 
the equilibrium phase diagram. Along with the high-
temperature -Mo2N phase with a cubic lattice, low-
temperature phase -Mo2N with a tetragonal lattice is 
revealed, its content increases with increasing the dep-
osition rate. At a pressure of about 0.07 Pa hardness of 
coatings reaches its maximum (45 ... 55) GPa. In the 
coatings with higher hardness the average size of 
grains (crystallites) is about 15 nm at a value of mi-
crostrain 0.4%. 
Typical X-ray diffraction spectra of the coatings Mo-
N, obtained at pressures of 0.06 ... 0.2 Pa and a low 
bias ( 40 V) are shown in Fig. 1. 
If we examine the influence of the thickness of 
coatings on the appearance of preferred orientation of 
growth of crystallites -Mo2N phase with a cubic lattice 
(structural type NaCl), then under small thickness 
((0.7 – 1.1) microns) texture with the growth axis 
perpendicular to the surface [100] is formed. This 
becomes apparent in the relative intensity amplification 
of diffraction peaks from the planes (200) and (400). In 
the thick coatings with the thickness of (4.5 – 7) microns 
the preferred orientation of crystallites with the plane 
(311) parallel to the growth surface is formed, i.e. with 
 А.А. ANDREEV, S. N. GRIGOREV, O.V. SOBOL, ET AL. PROC. NAP 1, 02NFC04(2012) 
 
 
02NFC04-2 
the texture axis [311]. It should be noted that the 
texture formed in the -Mo2N phase is a weak texture, 
as width at half maximum while ψ-scanning of this 
texture was 30° (  > 30°) for a plane (311). 
 
 
 
Fig. 1 – X-ray diffraction spectra of Mo-N coatings with low 
potential for bias ( 40 V): 1 – PN  0,06 Pa. 2 – PN  0,2 Pa 
 
In case of a large potential bias ( 200V) secondary 
sputtering of the nitrogen atoms from the surface leads 
to the change of phase composition and to appearance 
of intense diffraction peaks of the solid solution of ni-
trogen in molybdenum with a bcc-lattice. 
 
4. CONCIUSION 
 
An increase in the bias potential leads to predomi-
nant [111] orientation of the growing molybdenum ni-
tride crystals with a NaCl-type cubic lattice ( -Mo2N 
phase) and the appearance of a second phase with a 
body-centered cubic crystal lattice that is characteristic 
of pure molybdenum.  
The elastically strained (stressed) state of the coat-
ing is determined not only by the conditions of deposi-
tion, but also by the mechanical properties of a sub-
strate. Elastic macrostress-deformed state of coatings, 
determined by the method of multiple inclined surveys, 
have been contracting. The  magnitude of macrodefor-
mation for coatings with the greatest firmness reached 
high values 1.9 ... 2.0%.  
 
 
REFERENCES 
 
1. A.A. Andreev, L.P. Sablev, S.N. Grigor`ev, Vacuum-Arc 
Deposited Coatings (Institute of Physics and Technology, 
Kharkov, 2010).  
2. A.N. Azarenkov, O.V. Sobol ,` A.D. Pogrebnyak, V.M. Beresnev, 
Engeineering of Vacuum Deposited Coatings (Kharkov National 
University, Kharkov, 2011). 
3. A.P. Shpak, O.I. Nakonechnaya, Yu.A. Kunits`kii, 
O.V. Sobol`, Mechanical Properties of Titanium-based 
Coatings (Institute of Metal Physics: Kiev: 2005). 
 


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Structural-phase and Strained State of Vacuum-ARC Mo-N Coatings

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