The deposition temperature and proton radiation influence on the structure and stress-strain state of Ti‑W‑C system ion-plasma coatings was studied by the methods of wide-angle X-ray diffractometry combined with tensometry. It is found out that during sputtering MeC targets (where Me is a solid solution in the lattice of Ti and W atoms) when the ratio Ti / W reduces the transition from the one-phase state from (Ti, W)C carbide to the  two-phase state takes place where the second one is represented by the lower in carbon a‑W2C‑phase. Formation of lower phases correlates with depleting the composition by the interstitial element (C) while the content of W in the coating increases that has a relatively small heat of the carbide formation value. Essential changes under irradiation with protons of 200 keV to dose of 6.5×1017 cm-2 occur only in a stress-strain state

Shovkoplias, Oksana Anatoliivna

Sobol, O.V.

Шовкопляс, Оксана Анатольевна

Шовкопляс, Оксана Анатоліївна

Electronic Sumy State University Institutional Repository

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE  NANOMATERIALS: APPLICATIONS AND PROPERTIES Vol. 3 No 1, 01FNC05(4pp) (2014)   2304-1862/2014/3(1)01FNC05(4) 01FNC05-1  2014 Sumy State University Influence of Thermal Factor and Radiation Processing on the Structure and Stress State  of TiC-WC System Ion-plasma Coatings  O.A. Shovkoplyas1,*, O.V. Sobol’2  1 Sumy State University, 2, Rymsky Korsakov Str., 40007 Sumy, Ukraine 2 National Technical University "Kharkiv Polytechnical Institute", 21, Frunze Str., 61002 Kharkiv, Ukraine  (Received 15 July 2014; published online 29 August 2014)  The deposition temperature and proton radiation influence on the structure and stress-strain state of Ti-W-C system ion-plasma coatings was studied by the methods of wide-angle X-ray diffractometry com-bined with tensometry. It is found out that during sputtering MeC targets (where Me is a solid solution in the lattice of Ti and W atoms) when the ratio Ti / W reduces the transition from the one-phase state from (Ti, W)C carbide to the  two-phase state takes place where the second one is represented by the lower in carbon -W2C-phase. Formation of lower phases correlates with depleting the composition by the intersti-tial element (C) while the content of W in the coating increases that has a relatively small heat of the car-bide formation value. Essential changes under irradiation with protons of 200 keV to dose of 6.5 1017 cm-2 occur only in a stress-strain state.  Keywords: Ion-plasma coatings, Nanostructure, Ti-W-С System, Phase composition, X-ray diffraction in-vestigation, Stress-strain state, Thermal factor, Heat of the formation, Proton irradiation.   PACS numbers: 81.07.Bc, 81.15.Cd, 61.05.cp, 64.60.My, 61.50.Ks                                                             * sana@mss.sumdu.edu.ua 1. INTRODUCTION  The solid solution ion-plasma coatings on the basis of quasi-binary systems of interstitial phases are those ones that have been most intensively studied recently that is determined first and foremost by high mechani-cal properties which can be received only in the sys-tems of such a type as a result of separation and order-ing [1–9]. The great difference as to the chemical activity to the atoms of interstitial elements (B, C, N) and differ-ent types of lattices in an equilibrium state conditioned by it in combination with the considerable divergence as to masses and diffraction capacity correspondingly make the atoms of Ti and W perspective components for the coatings of quasi-binary systems. The aim of the paper consists in establishing the regularities of the thermal factor and radiation pro-cessing influence on the structure and stress state of ion-plasma-coatings received by magnetron sputtering of quasi-binary WC-TiC system.  2. EXPERIMENTAL DETAILS  The coatings have been received by the ion sputter-ing (magnetron scheme) of hot pressed targets with different volume contents of their constituent WC- and TiC-components (from 5 to 100 mol.% TiC). The planar magnetron scheme has been used for sputtering. The sputtering has been carried out in the medium of the inert gas Ar under the pressure (2–3) mTorr. The depo-sition speed is approximately 0.3 nm/s. Monocrystalline silicon, 370 µm thick, served as a substrate. Irradiation has been performed by the beam of pro-tons and electrons that has been spread on the area of 100 cm2 with the general proton and electron flux of 5–20 μA. The phase composition, structure and substructure of condensates have been researched by the methods of X-ray diffractometry on the apparatus DRON-3M in Cu – K  radiation. The volumel percent of phases in the film has been calculated by the standard methods re-garding the integral intensivity and reflective capacity of several lines of each phase. The analysis of phase composition of coatings has been carried out resorting to the card file ASTM. Substructural properties have been defined by the method of approximating the dif-fraction line profile form [10]. Тhe composition has been defined on fluorescent da-ta by the method of energy-dispersive spectroscopy, EDX.  The electron microscopy researches have been held on the transmission electron microscope TEM-U (“Selmi”, Sumy) at the accelerating voltage 100 kV and electron microscope photos enlargement of 108 000−270 000. The microscope resolution on atomic planes has made 0.2 nm. Ion thinning of film samples, a micron thick, has been made by Xe ions with the en-ergy 5 keV both on the side turned to the substrate and on the condensation surface side. The angle between the ion beam and the sample surface has been equal to 12° while thinning.  3. RESULTS AND DISCUSSION  The phase state analysis on the basis of X-ray diffractory data concerning the spectra of coatings received at Тs  570 K with different content of the constituents (Fig. 1) has shown that a one-phase structural state of the solid solution carbide (Ti, W)C is being formed (structural type NaCl, the overview of the lattice is displayed as an insertion in the Fig. 1). When the content of TiC-component increases the transition  O.A. SHOVKOPLYAS, O.V. SOBOL’ PROC. NAP 3, 01FNC05 (2014)   01FNC05-2 from a non-textured state to a preferred orientation (200) (with the composition 10 mol.% TiC – 90 mol.% WC) takes place. When the content of TiC-component is more a preferred orientation (111) of crystalites is being formed.  30 40 50 60 70 80020406080100120140160180200(222)(Ti,W)C(311)(Ti,W)C(220)(Ti,W)C(200)(Ti,W)C 2 , degI, a. u.(111)(Ti,W)C32154a    b  Fig. 1 – Plots of diffraction pattern from TiC-WC quasi-binary system coatings (Тs = 570 K) for the sputtering target composi-tions: 1 – 5 mol.% TiC – 95 mol.% WC, 2 – 10 mol.% TiC – 90 mol.% WC, 3 – 50 mol.% TiC – 50 mol.% WC, 4 – 75 mol.% TiC – 25mol.% WC, 5 – 90 mol.% TiC – 10 mol.% WC (а); electron microscope photo of the coating with the composition 5 mol.% TiC – 95 mol.% WC (b)  The higher deposition temperature Тs  970 K and a small content of TiC-component form a two-phase state: apart from the (Ti, W)C-phase crystallites with the (200) preferred orientation the formation of tungsten carbide with lower carbon content (W2C) takes place. According to HRTEM (high resolution transmission electron microscopy) the phase separation leads to the formation of the cellular ordered structure with the average size of the cells 5 nm (Fig. 2b). When the target has a composition of 10 mol.% TiC – 90 mol.%WC we can witness the formation of the one-phase (Ti, W)C state with the preferred orientation of the plane (200) parallel to the surface (Spectrum 2 in Fig. 2a). The greater TiC content forms a texture (111). The elemental analysis carried out by energy dispersive X-ray spectroscopy has shown that received coatings are depleted by light atoms. It can be connected with the secondary sputtering during the growth of coatings. The increase in titanium content contributes to the relative growing content of carbon in the coating. It should be mentioned that TiC has high heat of formation (–183.8 kJ/mol). The heat of formation of WC is considerably lower (–37.7 kJ/mol) and a compound is less stable [11].  30 40 50 600100200300400 2 , degI, a. u.32154(002) W2C(101) W2C(100) W2C(220) (Ti,W)C(200) (Ti,W)C(111) (Ti,W)C a    b  Fig. 2 – Plots of diffraction pattern from TiC-WC quasi-binary system coatings (Тs = 970 K) for the sputtering target composi-tions: 1 – 5 mol.% TiC – 95 mol.% WC, 2 –10 mol.% TiC – 90 mol.% WC, 3 – 50 mol.% TiC – 50 mol.% WC, 4 – 90 mol.% TiC – 10 mol.% WC, 5 – 100 mol.% TiC (а); electron microscope photo of the coating with the composition 5 mol.% TiC – 95 mol.% WC (b)  At the highest deposition temperature Тs = 1120 К (Fig. 3) and the lowest content of titanium carbide component in the target the three-phase state is formed where alongside with the carbide of solid solution (Ti, W)C and lower tungsten carbide W2C there appears a component much more depleted in carbon – -W (Spectrum 1 in Fig. 3a). In this case the following char-acteristic chain of states: W2C and (Ti, W)C with the preferred orientation (200) → (Ti, W)C with the pre-ferred orientation (200) → (Ti, W)C with the preferred orientation (111) – shifts in the direction of a higher titanium carbide content. For example, the second stage (Ti, W)C with the preferred orientation (200) – in the direction of the composition 20 mol.% TiC – 80 mol.% WC, in contrast to Тs = 570–770 K when such a texture is revealed only when the content makes 10 mol.% TiC and less. 10 nm 10 nm  THERMAL FACTOR AND RADIATION PROCESSING… PROC. NAP 3, 01FNC05 (2014)   01FNC05-3 As seen from the photos of high-resolution trans-mission electron microscopy (Fig. 3b) three-phase con-dition manifests itself as an area of 10–20 nm strongly depleted in the central portion of the carbon ( -W, black formations in the figure), which are surrounded by lighter formations with the size 30–100 nm (pre-sumably W2C-phase) and detached from the lightest areas (Ti, W)C with the size 10–30 nm.  30 40 50 6001002003004005006007008009001000(110) W2C(102) W2C 2 , degI, a. u.3214(002) W2C(101) W2C(100) W2C(220) (Ti,W)C(200) (Ti,W)C(111) (Ti,W)C(101) W2C(110)W a    b  Fig. 3 – Plots of diffraction patterns from TiC-WC quasi-binary system coatings received at Тs = 1120–1170 K: 1 – 5 mol.% TiC – 95 mol.% WC, 2 – 10 mol.% TiC – 90 mol.% WC, 3 – 20 mol.% TiC – 80 mol.% WC, 4 – 75 mol.% TiC – 25mol.% WC (а); electron microscope photo of the coating with the composition 5 mol.% TiC – 95 mol.% WC (b)  Proton beam irradiation has not changed the types of diffraction patterns principally. Thus, the phase composition and structure (on the texture level) of car-bide quasi-binary system coatings can be considered stable to the irradiation simulating the factors of the open space. The analysis of substructural characteristics con-cerning the widening diffraction reflexes of coatings before and after irradiation has shown that the size of crystallites does not change, if anything, remaining on the level 28–31 nm in the case of strong texture [111] when the content of TiC-component is large. When the content of WC-component is large the size of crystal-lites is much smaller: at the deposition temperature 570 К it makes 8–9 nm, and at the temperature 770 K the average size of crystallites increases up to 10–12 nm. “a-sin2 ”-method has been used in the work to in-vestigate stress-strain states. The coatings under in-vestigation have been exposed to compression stresses leading to the compression strain ( ) in the coating growth plane. It was being disclosed in reduction of the lattice spacing when the angle of inclination  from the normal to the surface  plane increased. The value of the lattice compression strain in coatings with the low con-tent of TiC-component (10–30 mol.%) in the postcon-densational state was from –0.5 to –1.4%. The maxi-mum value of the compression strain in the coating was higher and reached from –2.4 to –2.5% when the con-tent of TiC-component was high. Table 1 presents the results of researching into the macrostrain state of unirradiated and irradiated coat-ing parts (to reduce a mistake in comparing a half of the coating was covered tightly with metal foil that allowed the film to be under the foil in the initial (unir-radiated) state).  Table 1 – Results of investigating a macrostrain state of  coatings by “а-sin2 ”-method  Coating composition Ts, К , % / , % а0, nm initial irradiated 90 mol.% TiC – 10 mol.% WC 570 –2.4 –1.8 25.0 0.4332 80 mol.% TiC – 20 mol.% WC 570 –2.2 –1.55 29.5 0.4327 30 mol.% TiC – 70 mol.%WC 570 –1.27 –0.65 49.0 0.4293 20 mol.% TiC – 80 mol.% WC 770 –0.95 –0.4 58.0 0.4287  As one can see in Table 1 there is a general tenden-cy for all the investigated samples: irradiation contrib-utes to the partial relaxation of the initial compression strain. Therefore, on the exposure to irradiation there takes place relaxation of the growth compression strain that becomes most apparent in coatings enriched with WC component reaching the relative change by 29.5% at the proton irradiation dose of 6.5 1017 cm-2. Summing up the achieved results we can make a schematic phase-texture diagram (Fig. 4). It is clear that a one-phase state of carbide (Ti, W)C with the cu-bic lattice of NaCl structural type in the case of the relatively low deposition temperature (to 870 K) spreads to the whole concentrational range. It should be mentioned that unlike simple heating when the growing temperature increases the degree of disorder due to more vacancies the increasing substrate temper-ature during deposition forms a more equilibrium state in comparison with deposition at low temperatures. It is conditioned by the fact that deposited particles have a relatively high energy and the temperature equiva-lent to it, that is why the higher the deposition temper-ature is, the less the supercooling is while thermalizing such particles.   10 nm  O.A. SHOVKOPLYAS, O.V. SOBOL’ PROC. NAP 3, 01FNC05 (2014)   01FNC05-4   Fig. 4 – Schematic representation of the phase-texture dia-gram of quasi-binary TiC-WC system ion-plasma coatings  Then formation of (Ti, W)C phase with a relatively simple lattice in the whole concentrational range (see the bottom of Fig. 4) can be explained by relatively low diffusion mobility during great supercooling that stabi-lizes high-temperature phases with cubic lattices. In particular, it concerns a part of TiC-WC system for the high content of WC-component that forms the phase with the hexagonal lattice at these temperatures in an equilibrium state. The quasi-binary TiC-WC system coatings have dis-played the resistance to irradiation both on the phase composition level and the structural-substructural one.  ACKNOWLEDGMENTS  The work was performed as part of the budget financing themes: “Creation and use in industrial practice ion-plasma nanostructured superhard multilayer coatings with the deposition temperature of 120 °C or more” (state registration number 0110U004717, National Academy of Sciences of Ukraine) and “Investigating the evolution of structural and phase state of multicomponent composite materials and coatings under the external influence” (state registration number 0113U001079, Ministry of Education and Science of Ukraine).   REFERENCES  1. H. Willmann, P.H. Mayrhofer, P.O.A. Persson, A.E. Reiter, L. Hultman, C. Mitterer, Scripta Mater. 54, 1847 (2006). 2. A.D. Pogrebnjak, A.P. Shpak, N.A. Azarenkov, V.M. Beresnev, Phys. Usp. 52 No 1, 29 (2009). 3. O.V. Sobol', A.D. Pogrebnyak, V.M. Beresnev, Phys. Met. Metallogr. 112 No 2, 188 (2011). 4. Nanostrukturniye pokrytiya (Red. A. Kavaleyro, D. de Khossona) (М.: Tekhnosfera: 2011). 5. P.H. Mayrhofer, C. Mitterer, L. Hultman, H. Clemens, Prog. Mater. Sci. 51, 1032 (2006). 6. P.H. Mayrhofer, C. Mitterer, J.G. Wen, J.E. Greene, I. Petrov, Appl. Phys. Lett. 86, 131909 (2005). 7. O.V. Sobol’, O.A. Shovkoplyas, Metallofiz. Noveish. Tech-nol. 36 No 1, 49 (2014). 8. J. Musil, Surf. Coat. Tech. 207, 50 (2012). 9. A.D. Pogrebnjak, O.V. Sobol, V.M. Beresnev, P.V. Turbin, G.V. Kirik, N.A. Makhmudov, M.V. Il'yashenko, A.P. Shypylenko, M.V. Kaverin, M.Yu. Tashmetov, A.V. Pshyk, Nanocomposite Coatings, in Nanostructured Materials and Nanotechnology IV: Ceramic Engineering and Science Proceedings 31 No 7, 127 (2010). 10. L.S. Palatnyk, M.Ya. Fuks, V.M. Kosevich, Mekhanizm obrazovaniya i substruktura kondensirovannykh plenok (М.: Nauka: 1972). 11. O.V. Sobol’, O.A. Shovkoplyas, J. Nano- Electron. Phys. 6 No 3, 03071 (2014).  

Influence of Thermal Factor and Radiation Processing on the Structure and Stress State  of TiC-WC System Ion-plasma Coatings

SocioEconomic Challenges Journal (Sumy State University)

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE  
NANOMATERIALS: APPLICATIONS AND PROPERTIES 
Vol. 3 No 1, 01FNC05(4pp) (2014) 
 
 
2304-1862/2014/3(1)01FNC05(4) 01FNC05-1  2014 Sumy State University 
Influence of Thermal Factor and Radiation Processing on the Structure and Stress State  
of TiC-WC System Ion-plasma Coatings 
 
O.A. Shovkoplyas1,*, O.V. Sobol’2 
 
1 Sumy State University, 2, Rymsky Korsakov Str., 40007 Sumy, Ukraine 
2 National Technical University "Kharkiv Polytechnical Institute", 21, Frunze Str., 61002 Kharkiv, Ukraine 
 
(Received 15 July 2014; published online 29 August 2014) 
 
The deposition temperature and proton radiation influence on the structure and stress-strain state of 
Ti-W-C system ion-plasma coatings was studied by the methods of wide-angle X-ray diffractometry com-
bined with tensometry. It is found out that during sputtering MeC targets (where Me is a solid solution in 
the lattice of Ti and W atoms) when the ratio Ti / W reduces the transition from the one-phase state from 
(Ti, W)C carbide to the  two-phase state takes place where the second one is represented by the lower in 
carbon -W2C-phase. Formation of lower phases correlates with depleting the composition by the intersti-
tial element (C) while the content of W in the coating increases that has a relatively small heat of the car-
bide formation value. Essential changes under irradiation with protons of 200 keV to dose of 6.5 1017 cm-2 
occur only in a stress-strain state. 
 
Keywords: Ion-plasma coatings, Nanostructure, Ti-W-С System, Phase composition, X-ray diffraction in-
vestigation, Stress-strain state, Thermal factor, Heat of the formation, Proton irradiation. 
 
 PACS numbers: 81.07.Bc, 81.15.Cd, 61.05.cp, 
64.60.My, 61.50.Ks 
 
 
                                                          
* sana@mss.sumdu.edu.ua 
1. INTRODUCTION 
 
The solid solution ion-plasma coatings on the basis 
of quasi-binary systems of interstitial phases are those 
ones that have been most intensively studied recently 
that is determined first and foremost by high mechani-
cal properties which can be received only in the sys-
tems of such a type as a result of separation and order-
ing [1–9]. 
The great difference as to the chemical activity to 
the atoms of interstitial elements (B, C, N) and differ-
ent types of lattices in an equilibrium state conditioned 
by it in combination with the considerable divergence 
as to masses and diffraction capacity correspondingly 
make the atoms of Ti and W perspective components 
for the coatings of quasi-binary systems. 
The aim of the paper consists in establishing the 
regularities of the thermal factor and radiation pro-
cessing influence on the structure and stress state of 
ion-plasma-coatings received by magnetron sputtering 
of quasi-binary WC-TiC system. 
 
2. EXPERIMENTAL DETAILS 
 
The coatings have been received by the ion sputter-
ing (magnetron scheme) of hot pressed targets with 
different volume contents of their constituent WC- and 
TiC-components (from 5 to 100 mol.% TiC). The planar 
magnetron scheme has been used for sputtering. The 
sputtering has been carried out in the medium of the 
inert gas Ar under the pressure (2–3) mTorr. The depo-
sition speed is approximately 0.3 nm/s. Monocrystalline 
silicon, 370 µm thick, served as a substrate. 
Irradiation has been performed by the beam of pro-
tons and electrons that has been spread on the area of 
100 cm2 with the general proton and electron flux of 5–
20 μA. 
The phase composition, structure and substructure 
of condensates have been researched by the methods of 
X-ray diffractometry on the apparatus DRON-3M in 
Cu – K  radiation. The volumel percent of phases in the 
film has been calculated by the standard methods re-
garding the integral intensivity and reflective capacity 
of several lines of each phase. The analysis of phase 
composition of coatings has been carried out resorting 
to the card file ASTM. Substructural properties have 
been defined by the method of approximating the dif-
fraction line profile form [10]. 
Тhe composition has been defined on fluorescent da-
ta by the method of energy-dispersive spectroscopy, 
EDX.  
The electron microscopy researches have been held 
on the transmission electron microscope TEM-U 
(“Selmi”, Sumy) at the accelerating voltage 100 kV and 
electron microscope photos enlargement of 
108 000−270 000. The microscope resolution on atomic 
planes has made 0.2 nm. Ion thinning of film samples, 
a micron thick, has been made by Xe ions with the en-
ergy 5 keV both on the side turned to the substrate and 
on the condensation surface side. The angle between 
the ion beam and the sample surface has been equal to 
12° while thinning. 
 
3. RESULTS AND DISCUSSION 
 
The phase state analysis on the basis of X-ray 
diffractory data concerning the spectra of coatings 
received at Тs  570 K with different content of the 
constituents (Fig. 1) has shown that a one-phase 
structural state of the solid solution carbide (Ti, W)C is 
being formed (structural type NaCl, the overview of the 
lattice is displayed as an insertion in the Fig. 1). When 
the content of TiC-component increases the transition 
 O.A. SHOVKOPLYAS, O.V. SOBOL’ PROC. NAP 3, 01FNC05 (2014) 
 
 
01FNC05-2 
from a non-textured state to a preferred orientation 
(200) (with the composition 10 mol.% TiC –
 90 mol.% WC) takes place. When the content of 
TiC-component is more a preferred orientation (111) of 
crystalites is being formed. 
 
30 40 50 60 70 80
0
20
40
60
80
100
120
140
160
180
200
(2
2
2
)(
T
i,
W
)C
(3
1
1
)(
T
i,
W
)C
(2
2
0
)(
T
i,
W
)C
(2
0
0
)(
T
i,
W
)C
 
2 , deg
I,
 a
. 
u
.
(1
1
1
)(
T
i,
W
)C
3
2
1
5
4
a 
 
 
 
b 
 
Fig. 1 – Plots of diffraction pattern from TiC-WC quasi-binary 
system coatings (Тs = 570 K) for the sputtering target composi-
tions: 1 – 5 mol.% TiC – 95 mol.% WC, 
2 – 10 mol.% TiC – 90 mol.% WC, 
3 – 50 mol.% TiC – 50 mol.% WC, 
4 – 75 mol.% TiC – 25mol.% WC, 
5 – 90 mol.% TiC – 10 mol.% WC (а); 
electron microscope photo of the coating with the composition 
5 mol.% TiC – 95 mol.% WC (b) 
 
The higher deposition temperature Тs  970 K and a 
small content of TiC-component form a two-phase state: 
apart from the (Ti, W)C-phase crystallites with the 
(200) preferred orientation the formation of tungsten 
carbide with lower carbon content (W2C) takes place. 
According to HRTEM (high resolution transmission 
electron microscopy) the phase separation leads to the 
formation of the cellular ordered structure with the 
average size of the cells 5 nm (Fig. 2b). 
When the target has a composition of 10 mol.% TiC 
– 90 mol.%WC we can witness the formation of the one-
phase (Ti, W)C state with the preferred orientation of 
the plane (200) parallel to the surface (Spectrum 2 in 
Fig. 2a). The greater TiC content forms a texture (111). 
The elemental analysis carried out by energy 
dispersive X-ray spectroscopy has shown that received 
coatings are depleted by light atoms. It can be 
connected with the secondary sputtering during the 
growth of coatings. The increase in titanium content 
contributes to the relative growing content of carbon in 
the coating. It should be mentioned that TiC has high 
heat of formation (–183.8 kJ/mol). The heat of 
formation of WC is considerably lower (–37.7 kJ/mol) 
and a compound is less stable [11]. 
 
30 40 50 60
0
100
200
300
400
 
2 , deg
I,
 a
. 
u
.
3
2
1
5
4
(0
0
2
) 
W
2
C
(1
0
1
) 
W
2
C
(1
0
0
) 
W
2
C
(2
2
0
) 
(T
i,
W
)C
(2
0
0
) 
(T
i,
W
)C
(1
1
1
) 
(T
i,
W
)C
 
a 
 
 
 
b 
 
Fig. 2 – Plots of diffraction pattern from TiC-WC quasi-binary 
system coatings (Тs = 970 K) for the sputtering target composi-
tions: 1 – 5 mol.% TiC – 95 mol.% WC, 
2 –10 mol.% TiC – 90 mol.% WC, 
3 – 50 mol.% TiC – 50 mol.% WC, 
4 – 90 mol.% TiC – 10 mol.% WC, 
5 – 100 mol.% TiC (а); 
electron microscope photo of the coating with the composition 
5 mol.% TiC – 95 mol.% WC (b) 
 
At the highest deposition temperature Тs = 1120 К 
(Fig. 3) and the lowest content of titanium carbide 
component in the target the three-phase state is formed 
where alongside with the carbide of solid solution 
(Ti, W)C and lower tungsten carbide W2C there appears 
a component much more depleted in carbon – -W 
(Spectrum 1 in Fig. 3a). In this case the following char-
acteristic chain of states: W2C and (Ti, W)C with the 
preferred orientation (200) → (Ti, W)C with the pre-
ferred orientation (200) → (Ti, W)C with the preferred 
orientation (111) – shifts in the direction of a higher 
titanium carbide content. For example, the second 
stage (Ti, W)C with the preferred orientation (200) – in 
the direction of the composition 20 mol.% TiC –
 80 mol.% WC, in contrast to Тs = 570–770 K when such 
a texture is revealed only when the content makes 
10 mol.% TiC and less. 
10 nm 
10 nm 
 THERMAL FACTOR AND RADIATION PROCESSING… PROC. NAP 3, 01FNC05 (2014) 
 
 
01FNC05-3 
As seen from the photos of high-resolution trans-
mission electron microscopy (Fig. 3b) three-phase con-
dition manifests itself as an area of 10–20 nm strongly 
depleted in the central portion of the carbon ( -W, 
black formations in the figure), which are surrounded 
by lighter formations with the size 30–100 nm (pre-
sumably W2C-phase) and detached from the lightest 
areas (Ti, W)C with the size 10–30 nm. 
 
30 40 50 60
0
100
200
300
400
500
600
700
800
900
1000
(1
1
0
) 
W
2
C
(1
0
2
) 
W
2
C
 
2 , deg
I,
 a
. 
u
.
3
2
1
4
(0
0
2
) 
W
2
C
(1
0
1
) 
W
2
C
(1
0
0
) 
W
2
C
(2
2
0
) 
(T
i,
W
)C
(2
0
0
) 
(T
i,
W
)C
(1
1
1
) 
(T
i,
W
)C
(1
0
1
) 
W
2
C
(1
1
0
)
W
 
a 
 
 
 
b 
 
Fig. 3 – Plots of diffraction patterns from TiC-WC quasi-
binary system coatings received at Тs = 1120–1170 K: 
1 – 5 mol.% TiC – 95 mol.% WC, 
2 – 10 mol.% TiC – 90 mol.% WC, 
3 – 20 mol.% TiC – 80 mol.% WC, 
4 – 75 mol.% TiC – 25mol.% WC (а); 
electron microscope photo of the coating with the composition 
5 mol.% TiC – 95 mol.% WC (b) 
 
Proton beam irradiation has not changed the types 
of diffraction patterns principally. Thus, the phase 
composition and structure (on the texture level) of car-
bide quasi-binary system coatings can be considered 
stable to the irradiation simulating the factors of the 
open space. 
The analysis of substructural characteristics con-
cerning the widening diffraction reflexes of coatings 
before and after irradiation has shown that the size of 
crystallites does not change, if anything, remaining on 
the level 28–31 nm in the case of strong texture [111] 
when the content of TiC-component is large. When the 
content of WC-component is large the size of crystal-
lites is much smaller: at the deposition temperature 
570 К it makes 8–9 nm, and at the temperature 770 K 
the average size of crystallites increases up to 10–
12 nm. 
“a-sin2 ”-method has been used in the work to in-
vestigate stress-strain states. The coatings under in-
vestigation have been exposed to compression stresses 
leading to the compression strain ( ) in the coating 
growth plane. It was being disclosed in reduction of the 
lattice spacing when the angle of inclination  from the 
normal to the surface  plane increased. The value of the 
lattice compression strain in coatings with the low con-
tent of TiC-component (10–30 mol.%) in the postcon-
densational state was from –0.5 to –1.4%. The maxi-
mum value of the compression strain in the coating was 
higher and reached from –2.4 to –2.5% when the con-
tent of TiC-component was high. 
Table 1 presents the results of researching into the 
macrostrain state of unirradiated and irradiated coat-
ing parts (to reduce a mistake in comparing a half of 
the coating was covered tightly with metal foil that 
allowed the film to be under the foil in the initial (unir-
radiated) state). 
 
Table 1 – Results of investigating a macrostrain state of  
coatings by “а-sin2 ”-method 
 
Coating 
composition 
Ts, К 
, % 
/ , % а0, nm 
initial irradiated 
90 mol.% TiC – 
10 mol.% WC 
570 –2.4 –1.8 25.0 0.4332 
80 mol.% TiC – 
20 mol.% WC 
570 –2.2 –1.55 29.5 0.4327 
30 mol.% TiC – 
70 mol.%WC 
570 –1.27 –0.65 49.0 0.4293 
20 mol.% TiC – 
80 mol.% WC 
770 –0.95 –0.4 58.0 0.4287 
 
As one can see in Table 1 there is a general tenden-
cy for all the investigated samples: irradiation contrib-
utes to the partial relaxation of the initial compression 
strain. Therefore, on the exposure to irradiation there 
takes place relaxation of the growth compression strain 
that becomes most apparent in coatings enriched with 
WC component reaching the relative change by 29.5% 
at the proton irradiation dose of 6.5 1017 cm-2. 
Summing up the achieved results we can make a 
schematic phase-texture diagram (Fig. 4). It is clear 
that a one-phase state of carbide (Ti, W)C with the cu-
bic lattice of NaCl structural type in the case of the 
relatively low deposition temperature (to 870 K) 
spreads to the whole concentrational range. It should 
be mentioned that unlike simple heating when the 
growing temperature increases the degree of disorder 
due to more vacancies the increasing substrate temper-
ature during deposition forms a more equilibrium state 
in comparison with deposition at low temperatures. It 
is conditioned by the fact that deposited particles have 
a relatively high energy and the temperature equiva-
lent to it, that is why the higher the deposition temper-
ature is, the less the supercooling is while thermalizing 
such particles.  
 
10 nm 
 O.A. SHOVKOPLYAS, O.V. SOBOL’ PROC. NAP 3, 01FNC05 (2014) 
 
 
01FNC05-4 
 
 
Fig. 4 – Schematic representation of the phase-texture dia-
gram of quasi-binary TiC-WC system ion-plasma coatings 
 
Then formation of (Ti, W)C phase with a relatively 
simple lattice in the whole concentrational range (see 
the bottom of Fig. 4) can be explained by relatively low 
diffusion mobility during great supercooling that stabi-
lizes high-temperature phases with cubic lattices. In 
particular, it concerns a part of TiC-WC system for the 
high content of WC-component that forms the phase 
with the hexagonal lattice at these temperatures in an 
equilibrium state. 
The quasi-binary TiC-WC system coatings have dis-
played the resistance to irradiation both on the phase 
composition level and the structural-substructural one. 
 
ACKNOWLEDGMENTS 
 
The work was performed as part of the budget 
financing themes: “Creation and use in industrial 
practice ion-plasma nanostructured superhard 
multilayer coatings with the deposition temperature of 
120 °C or more” (state registration number 
0110U004717, National Academy of Sciences of 
Ukraine) and “Investigating the evolution of structural 
and phase state of multicomponent composite materials 
and coatings under the external influence” (state 
registration number 0113U001079, Ministry of 
Education and Science of Ukraine). 
 
 
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Influence of Thermal Factor and Radiation Processing on the Structure and Stress State of TiC-WC System Ion-plasma Coatings

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