Mechanical-properties-and-oxidation-resistance-of-_2019_International-Journa

Esta é uma pré-visualização de arquivo. Entre para ver o arquivo original

Contents lists available at ScienceDirect
International Journal of Refractory Metals
& Hard Materials
journal homepage: www.elsevier.com/locate/IJRMHM
Mechanical properties and oxidation resistance of chemically vapor
deposited TiSiN nanocomposite coating with thermodynamically designed
compositions
Lianchang Qiua, Yong Dua,⁎, Shaoqing Wangb, Kai Lia,⁎, Lei Yinc, Liying Wua, Zhiqiang Zhonga,
Layyous Albird
a State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083, China
b School of Materials Science and Engineering, Shijiazhuang Tiedao University, Shijiazhuang, Hebei 050043, China
cGanzhou Achteck Tool Technology Co,. Ltd., Ganzhou, Jiangxi 341000, China
d Layyous Consulting Ltd., Miilya 25140, Israel
A R T I C L E I N F O
Keywords:
Chemical vapor deposition
TiSiN coating
Thermodynamic calculation
Hardness
Oxidation resistance
A B S T R A C T
TiSiN coating with nanocrystallite surrounded by amorphous phase has attracted a broad interest because of its
high hardness and excellent oxidation resistance desired for cutting tools. In the present work, TiSiN coatings
were designed and prepared from a gaseous mixture of TiCl4, SiCl4, NH3 and H2 by low pressure chemical vapor
deposition (CVD) process under the guidance of calculated CVD phase diagrams. The calculated compositions
and phases in the deposited coatings agree well with the experimental ones. The deposited TiSiN coatings consist
of nano-crystalline TiN and amorphous Si3N4 (a-Si3N4). A maximum hardness of about 2800 HV0.02 was ob-
tained, corresponding to a minimum crystallite size of 17.7 nm and a-Si3N4 volume fraction of 13.3% for TiSiN
coating deposited at 1123 K under 3.0 kPa. After oxidation at 973 K for 1 h, TiSiN coating kept intact while TiN
was completely oxidized. TiSiN nanocomposite coating formed by Si incorporation to TiN displayed superior
hardness and oxidation resistance in comparison with those of TiN. The correlation of TiSiN coating hardness
with volume fraction of a-Si3N4 and TiN grain size was discussed. The present work demonstrates a novel
strategy of thermodynamic calculations and key experiments to deposit CVD TiSiN coatings highly efficiently,
which is equally valid for the design of other CVD hard coatings.
1. Introduction
The first publication of Ti-Si-N films was from Li et al. [1] in 1992,
and the first report for the design of superhard Ti-Si-N nanocomposites
was from Veprek et al. [2] in 1995. Subsequently, Veprek et al. [3]
reported multiphase nanocomposite coatings with hardness range from
80 to 105 GPa and proposed the lowest hardness to be 158 GPa [4] for
nc-TiN/a-Si3N4 (nc- stands for nanocrystalline) nanocomposites with
completely segregated phases and one monolayer of SiNx interface
without impurities [5,6]. Several deposition methods, such as Chemical
Vapor Deposition (CVD) [7–12], Plasma-Enhanced or Plasma-Assisted
Chemical Vapor Deposition (PE or PACVD) [1,13,14], Magnetron
Sputtering [15,16] and Cathodic Arc Evaporation [17–20], have been
utilized to deposit TiSiN coatings. TiSiN nanocomposite coating consists
of crystalline TiN (grain size usually< 100 nm) surrounded by amor-
phous phase. Such coatings provide high hardness and good oxidation
resistance, leading to excellent cutting performance [21]. After an-
nealing in air for 1 h at 1073 K, the TiSiN coating surface keeps intact
depending on the composition [22].
In cutting tool industry with cemented carbides as the substrates,
CVD is extensively used for the preparation of coatings, such as TiN
[23], TiB2 [24], Ti(C,N) [25], Al2O3 [26] and TiAlN [27], owing to its
better step coverage and relatively thicker coatings than PVD coatings,
which are beneficial to turning operation. Various studies using CVD to
deposit TiSiN coatings were published. Hirai and Hayashi [8] prepared
Si3N4-TiN composites by CVD from 1323 to 1723 K using the SiCl4-
TiCl4-NH3-H2 system. Three types of composites having amorphous, α-
and β-Si3N4 matrices were obtained. Llauro et al. [9] investigated CVD
TiSiN coatings deposited from TiCl4-SiH2Cl2-NH3 or N2-H2 precursor
system at 1123–1373 K. The coatings consisting of TiSi2-Ti5Si3(N)-TiN
and TiSi2-a-Si3N4-TiN were prepared when NH3 was used as the ni-
trogen source. The incorporation of TiSi2-Ti5Si3(N) or only Ti5Si3(N) in
https://doi.org/10.1016/j.ijrmhm.2018.12.018
Received 4 November 2018; Accepted 23 December 2018
⁎ Corresponding authors.
E-mail addresses: yong-du@csu.edu.cn (Y. Du), leking@csu.edu.cn (K. Li).
International Journal of Refractory Metals & Hard Materials 80 (2019) 30–39
Available online 24 December 2018
0263-4368/ © 2018 Elsevier Ltd. All rights reserved.
T
http://www.sciencedirect.com/science/journal/02634368
https://www.elsevier.com/locate/IJRMHM
https://doi.org/10.1016/j.ijrmhm.2018.12.018
https://doi.org/10.1016/j.ijrmhm.2018.12.018
mailto:yong-du@csu.edu.cn
mailto:leking@csu.edu.cn
https://doi.org/10.1016/j.ijrmhm.2018.12.018
http://crossmark.crossref.org/dialog/?doi=10.1016/j.ijrmhm.2018.12.018&domain=pdf
a TiN matrix was achieved with N2. Perez-Mariano et al. [11] studied
TiSiN coatings prepared by CVD at atmospheric pressure with TiCl4-
SiCl4-NH3-H2-Ar at 1123 K. Nanocomposite coatings consisting of
crystalline TiN and amorphous SiNx were obtained. TiSiN coating with
9 at.% Si showed a hardness of 28 GPa. Endler et al. [12] prepared
TiSiN nanocomposite coatings by low pressure chemical vapor de-
position (LPCVD) from a gaseous mixture of TiCl4-SiCl4-NH3-H2-Ar
between 1073 and 1173 K under 6 kPa. A maximum hardness of about
3700 HV0.01 was observed at a silicon content of 6–8 at.% with TiN
grain size of 15 nm approximately.
The silicon content in TiSiN coating plays a significant role in de-
termining its morphology and mechanical properties. Utilizing hybrid
HiPIMS and pulsed-DC magnetron co-sputtering, Arab Pour Yazdi et al.
[28] synthesized TiSiN coatings with silicon content from 0 to 8.8 at. %.
The TiSiN grain sizes decreased from ~41 to ~6 nm with the increase of
Si. The hardness increased from 20 ± 0.41 to 41.31 ± 2.93 GPa with
increasing Si content up to 4.4 at. %. Bartosik et al. [15] studied the
structural evolution as a function of Si content in TiSiN coatings. All
coatings exhibit columnar growth morphology as Si content increases
from 0 to 8.5 at. %. However, the TiSiN exhibits a more equiaxed
growth morphology when the Si content reaches 10.5 at. %.
The above mentioned TiSiN coatings were deposited mainly
through time and cost consuming experiments. An effective design for
deposition parameters, such as temperature, pressure and gas ratios
among the gases before experiment, would be quite helpful in order to
obtain desired coating. We have demonstrated the applications of
thermodynamic calculations during the deposition of CVD Ti(C,N) and
TiAlN coatings [29] used for cemented carbide cutting tools. In the
present work, we provided an effective approach to design composi-
tions for TiSiN coatings deposited by LPCVD in an industrial-scale CVD
reactor. The influence of precursors and deposition parameters on the
coating compositions and phases was displayed by the established CVD
phase diagram through thermodynamic calculations. Subsequently, key
experiments guided with these theoretical predictions were performed
to prepare TiSiN coatings. After that, microstructure, composition,
mechanical properties as well as oxidation resistance of the deposited
coatings were discussed in detail.
2. Thermodynamic calculations
Based on the minimization of the Gibbs energy [30], thermo-
dynamic calculations were performed by using Thermo-Calc software
[31] applied to SGTE substance database [32] appended with thermo-
dynamic parameters in the Ti-Si-N system [33]. TiSiN deposition pro-
cess was simulated through thermodynamic calculations on TiCl4-SiCl4-
NH3-H2 system. The Gibbs energy functions of the individual gas spe-
cies were taken from JANAF [34]. To get the high accuracy of the
calculations, all possible condensed and gaseous reaction
products were
considered in the present work. All the species is shown in Table 1. The
Ti-Si-N ternary system includes the following technologically important
phases with applications in cutting tools: (1) the diamond-Si phase
denoted as Si; (2) the ternary solution phases TiN, the solution of N and
Si in fcc Ti; and Ti5Si3Nx (denoted T1); (3) the ternary extension of the
binary phase Ti5Si3; (4) the stoichiometric compounds of Ti3Si, Ti5Si4,
TiSi, TiSi2, Si3N4 and Ti2N. The thermodynamic models and thermo-
dynamic parameters for the above phases in the Ti-Si-N ternary system
were taken from Ref. [33]. The thermodynamic parameters for pure
elements were from publication of Dinsdale [35].
With an aim to develop TiSiN coatings by LPCVD efficiently, firstly
the change of TiSiN coating composition with deposition temperature,
pressure and ratio of SiCl4/TiCl4 was predicted in Fig.1. The calculated
N content keeps constant while Ti increases and Si decreases as tem-
perature rises from 900 to 1400 K (Fig.1a). The TiSiN coating compo-
sition keeps almost unchanged for the pressure range from 0.1 to
6.0 kPa (Fig.1b). As the gas flow ratio R (SiCl4/SiCl4+TiCl4) increases
up to 0.81, both N and Si contents increase while Ti decreases con-
tinuously (Fig.1c). The coating consists of Si3N4 only with constant Si
and N contents for R > 0.81. Under fixed temperature and pressure, an
effective adjustment of the TiSiN coating composition could be realized
by changing the gas flow ratio R.
Fig. 2 displays the influence of deposition parameters on the de-
posited products for TiSiN coatings. As shown in Fig. 2a, single phase
TiN is formed with gas flow ratio R < 0.2, while TiN and Si3N4 co-exist
when R is within the range of 0.2–0.34 for TiSiN coating deposited at
900–1300 K. As R exceeds 0.34, additional phase TiSi2 occurs besides
TiN and Si3N4. A further increase of R to about 0.8 leads to the for-
mation of single phase Si3N4 for deposition temperature below about
1125 K. When keeping the temperature and pressure constant at 1123 K
and 3.0 kPa, respectively, the TiSiN coating phases are mainly de-
termined by the flow ratio of gases, as shown in Fig. 2b. TiN and Si3N4
co-exist in coating with NH3 > 2% and R < 0.8. No Si3N4 could be
formed when NH3 < 1.3% and R < 0.5. Higher SiCl4 gas flow with
R > 0.8 leads to the absence of TiN phase in TiSiN coating.
3. Experimental procedure
In the present work, it is expected to design TiSiN nanocomposite
coatings consisting of TiN and Si3N4 from TiCl4-SiCl4-NH3-H2 pre-
cursors. Different deposition temperatures and pressures were selected
based on calculations from Figs. 1a–b and 2a. The gas flow of precursors
was chosen according to the calculated results from Fig. 2b. TiSiN
coatings were deposited on TiN pre-coated (thickness about 1 μm) ce-
mented carbide substrates with 5.8% Co (WC grain size 0.8 μm, geo-
metry CNMA120408) from gaseous mixture of TiCl4 (purity 99.90%),
SiCl4 (99.90%), NH3 (99.995%) and H2 (99.95%), which was further
cleaned by an Oxisorb cartridge and used as carrier gas, in an industrial-
scale vertical hot wall reactor. The TiN coating was used to increase the
cohesion between the substrate and TiSiN hard coating. The deposition
conditions for TiN and TiSiN coatings were listed in Table 2. In all
experiments the cemented carbide substrates were wet blasted and
cleaned by ethanol in an ultrasonic bath before deposition. A schematic
diagram of the LPCVD deposition system is shown in Fig. 3. All the
gases were introduced at the bottom of reactor and pre-heated before
entering into the deposition zone. The NH3, TiCl4 and SiCl4 were in-
troduced by separated gas inlets in order to avoid the formation of solid
chloride-ammonia-complexes. The NH3 gas line was connected close to
the pre-heating zone, while TiCl4 and SiCl4 were mixed in a chamber
before entering into the reactor. The feed gas lines for TiCl4 and SiCl4
were heated to 473 K by heating tapes. The flow rates of all gases were
controlled by mass flow controllers.
The chemical compositions of TiSiN coatings were determined by
Electron Probe Micro-analyzer (EPMA, JXA-8230, JOEL, Japan)
equipped with Wavelength Dispersive Spectrometer (WDS). The mea-
sured chemical compositions were compared with the calculated ones.
Crystal structures were analyzed by X-ray diffraction (XRD, Bruker D8
Advanced, Germany) using Cu-Kα radiation. The XRD analysis allowed
Table 1
Phases considered in thermodynamic calculations.
Solid species Gaseous species
Ti, Si, TiN, Ti2N, Si3N4, TiSi,TiSi2, Ti3Si, Ti5Si3, Ti5Si3Nx,
Ti5Si4, TiCl2, TiCl3, TiH2
H, H2, N2, HCl, TiCl4, Cl, Cl2, Ti, Ti2, TiCl, TiCl2, TiCl3, TiCl4, TiCl6, Ti2Cl6, Si, Si2, Si3, SiH, SiH2, SiH3, SiH4,
Si2H6, SiCl, SiCl2, SiCl3, SiHCl, SiH3Cl, SiH2Cl2, SiHCl3, NH, N3H, NH2, NH3, N2H2, N2H4, N, TiN, SiN, SiN2, N3
L. Qiu et al. International Journal of Refractory Metals & Hard Materials 80 (2019) 30–39
31
the calculation of the crystallites mean size by applying the Debye-
Scherrer method [36]. X-ray photoelectron spectroscopy (XPS) analysis
was performed using a Thermo Fisher Scientific K-ALPHA. The XPS unit
was operated with excitation energy of Al-Kα 1486.6 eV and an exit
angle of 45°. The coating surface was sputter-cleaned with Ar for 2min
with 3 keV to remove contaminants before the XPS analysis. All the
peaks were calibrated by C 1 s peak (284.5 eV). Surface and fracture
morphologies of the coatings were examined by a field-emission scan-
ning electron microscope (FESEM, Supra 55, Zeiss, Germany). Detailed
microstructural analyses were performed by transmission electron mi-
croscopy (TEM) using FEI Tecnai G2 F20 unit with an operating voltage
of 300 kV. TEM specimens were prepared using a dual-beam focused
ion beam (FIB) system (FEI Helios Nanolab 600i) working under a va-
cuum of 5×10−4 kPa. Final surface cleaning was conducted at 5.0 kV
and 41 pA to remove the amorphous layer induced by FIB. Hardness
Fig. 1. Calculated compositions of TiSiN coatings as a function of (a) temperature, (b) total pressure and (c) flow ratio R. Conditions for thermodynamic calculations:
(a) P=3.0 kPa, T= 900–1400 K, H2= 95.63%, NH3=2.12%, TiCl4= 1.89%, SiCl4= 0.36%; (b) T= 1123 K, P=0–6 kPa, H2= 95.63%, NH3=2.12%,
TiCl4= 1.89%, SiCl4= 0.36%; (c) P= 3.0 kPa, T= 1123 K, NH3=2.12%, TiCl4= 1.89%, R=0–0.9, H2=Balance. R= x(SiCl4)/(x(SiCl4)+ x(TiCl4)).
Fig. 2. Influence of deposition parameters on the
deposited products (a) Temperature and flow ratio R;
(b) Gas flow of NH3 and flow ratio R. Conditions for
thermodynamic calculations: (a) P= 3.0 kPa,
T= 900–1300 K, H2= 95.63%, NH3=2.12%,
TiCl4= 1.89%, R=0–0.9; (b) P= 3.0 kPa,
T= 1123 K, H2=95.63%, TiCl4= 1.89%,
NH3= 0–3%, R=0–0.9; R= x(SiCl4)/(x(SiCl4)+ x
(TiCl4)).
Table 2
Deposition conditions for TiN and TiSiN coatings.
Deposition parameters TiNa TiSiN1 TiSiN2 TiSiN3
Temperature (K) 1123 1123 1273 1123
Pressure (kPa) 3.0 3.0 3.0 0.5
Time (min) 60 180 180 180
TiCl4 flow rate (sccm,1 atm., 298 K) 4.0 4.0 4.0 4.0
SiCl4 flow rate (sccm,1 atm., 298 K) – 0.8 0.8 0.8
NH3 flow rate (sccm,1 atm., 298 K) 1,000 1,000 1,000 1,000
H2 flow rate (sccm,1 atm., 298 K) 45,000 45,000 45,000 85,000
a TiN was deposited as an interlayer between substrate and TiSiN coating for
all the experiments.
Fig. 3. Schematic drawing of LPCVD system for TiSiN deposition.
L. Qiu et al. International Journal of Refractory Metals & Hard Materials 80 (2019) 30–39
32
measurements of TiSiN coatings were derived from nanoindentation
with Berkovich diamond tip using an instrumented nanoindenter
(Anton Paar, TTX-NHT2) after the Oliver and Pharr method [37]. A
penetration load of 20 mN with twenty indents was chosen to measure
the mechanical properties of the coatings to keep the indentation depth
(~200 nm) below 10% of the coating thickness.
The oxidation behaviour of TiSiN1 was studied by annealing at 973,
1023, 1073, 1123, and 1173 K for 1 h in air, while TiN samples were
only annealed at 973 K since they were fully oxidized at about 923 K.
The
weight gains after annealing were measured by an electronic bal-
ance with an accuracy of 0.1 mg. The phases of annealed samples were
identified by XRD also. The surface morphology of the annealed sam-
ples was characterized by SEM.
4. Results and discussion
4.1. Composition and morphology of the CVD TiSiN coating
Fig. 4 shows the calculated and measured chemical compositions of
TiSiN coatings. It can be seen that the calculated results agree well with
the measured ones. From Fig. 4a, it is indicated that the Si content of
TiSiN2 (5.4 at.%) coating is lower than that of TiSiN1 (5.8 at.%). Both
TiSiN1 and TiSiN2 coatings were deposited at 3.0 kPa, while TiSiN2
was deposited at 1273 K which was higher than that of TiSiN1. This
means that higher temperature leads to lower Si content, which is also
consistent with the calculated result in Fig. 1a. At high temperatures,
the reactants become more active and more chemical reactions might
occur, leading to more by-products containing Si. With the increase of
by-products, the Si content in TiSiN coating is reduced. The Si content
in TiSiN3 (5.6 at.%) is also slightly less than that of TiSiN1 although
both coatings were deposited at 1123 K. However, TiSiN3 was
deposited at 0.5 kPa which was lower than that of TiSiN1. This result
agrees well with that of Fig. 1b, showing lower Si content at lower
pressure. At lower pressure, the gas flow was faster, causing less re-
tention time of gases and insufficient SiCl4 on the surfaces of samples.
The differences of Ti (see Fig.4b) and N (see Fig.4c) contents among
TiSiN1, TiSiN2 and TiSiN3 coatings are correlated with those of Si since
the total atomic fraction of Si, Ti and N was assumed to be equal to 1 in
each coating.
The surface and cross-section morphologies of TiSiN coatings are
observed (Fig. 5). Fine granular grains are displayed on the TiSiN1
coating surface (Fig. 5a), and the incorporation of Si into TiN changes
the morphology from columnar to equiaxed (Fig. 5b). Due to the inward
diffusion of Si to the TiN adhesive layer, the bottom TiN layer also
appears equiaxed. When the deposition temperature increases to
1273 K under the same pressure, coarse granular grains are shown on
the TiSiN2 coating surface (Fig. 5c). The larger grains were caused by a
faster surface diffusion at higher temperature. Besides, the high tem-
perature also enables a fast growth rate, leading to more porous coating
(Fig. 5d). When the deposition pressure is lowered to 0.5 kPa at 1123 K,
finer granular grains are shown on the TiSiN3 coating surface (Fig. 5e)
compared with that of TiSiN1 deposited under 3.0 kPa at the same
temperature (Fig. 5a). Meanwhile, TiSiN3 coating demonstrates a very
dense structure (Fig. 5f). At a lower deposition pressure with the same
amount of gas precursors, the faster gas flow leads to less retention time
of gases on the sample surface. As a consequence, a lower growth rate is
obtained, leading to finer grains. The input of SiCl4 not only lowered
the reactivity between TiCl4 and NH3, but also reduced the surface
mobility of adsorbates, giving rise to nano-sized grains for all the de-
posited TiSiN coatings [7].
Fig. 6 presents XRD patterns of as-deposited TiSiN coatings. It can
be seen that the coatings are composed of TiN phases with (200)
Fig. 4. Calculated and measured chemical compositions of TiSiN coatings (a) Si; (b) Ti; (c) N.
L. Qiu et al. International Journal of Refractory Metals & Hard Materials 80 (2019) 30–39
33
preferred orientation, while no Si3N4 crystalline phase is detected. As
reported by Hira and Hayashi [8], Si3N4 is amorphous below 1473 K.
The absence of crystalline Si3N4 in our TiSiN coatings is reasonable
when considering the deposition temperatures (see Table 2). Peak shifts
toward higher 2θ angles can be observed for TiN (200) plane in all the
patterns due to Si incorporation into TiN. The ionic radius of Si4+ is
0.41 Å, which is much less than that of Ti3+ (0.75 Å). As a result, Si ion
can replace Ti sites in TiN lattice plane [38]. The replacement of Ti by
Si might cause the shrinkage of unit cell, leading to a reduction of inter-
planar spacing. Consequently, the diffraction peaks shift to higher an-
gles. The WC phases in all the XRD patterns are from the substrates. Due
to a higher coating thickness, WC was not detected in TiSiN2 sample.
Fig. 7 demonstrates the Si 2p (Fig. 7a) and N 1 s (Fig. 7b) spectra of
TiSiN1 coating containing 5.8 at.% Si. The Si 2p indicated a char-
acteristic peak at the binding energy of approximately 101.7 eV which
is consistent with the stoichiometric Si3N4 phase peak [39]. The N 1 s
spectrum displayed the peak characteristics of the nitrogen Si3N4 with
the binding energies at approximately 397.2 eV. Consequently, the XPS
measurements suggest the existence of Si3N4 in the coating. As men-
tioned above, no Si3N4 peaks could be observed from the XRD analysis
in Fig.6. This might be attributed to the amorphous form of the Si3N4 in
Fig. 5. Morphologies of TiSiN coatings (a) TiSiN1, surface, (b) TiSiN1, cross-section, (c) TiSiN2, surface, (d) TiSiN2, cross-section, (e) TiSiN3, surface, and (f) TiSiN3,
cross-section.
Fig. 6. XRD patterns of TiSiN coatings deposited at different conditions.
(Conditions: TiSiN1–1123 K/3.0 kPa; TiSiN2–1273 K/3.0 kPa; TiSiN3–1123 K/
0.5 kPa).
L. Qiu et al. International Journal of Refractory Metals & Hard Materials 80 (2019) 30–39
34
the coating.
Detailed microstructural investigations of TiSiN1 coating are further
conducted by cross-sectional TEM observations. As shown in Fig. 8a,
the TEM bright-field image of TiSiN1 coating presents nanocrystalline
morphology. The selected area electron diffraction (SAED) pattern in-
serted in Fig. 8a shows a polycrystalline face-centered cubic char-
acteristic. Besides, the high-resolution TEM image in Fig. 8b indicates
that the TiSiN coating consists of nano-sized TiN crystallites and
amorphous phase. This observation agrees with the previously reported
typical nanocomposite structure with crystalline TiN or (Ti,Si)N em-
bedded in the amorphous SiNx matrix for TiSiN coatings [40–42].
Consequently, the TiSiN coatings prepared in this work are con-
solidated to be nanocomposites with nano-grains embedded in amor-
phous Si3N4 phases according to the combined tests of XRD, XPS and
TEM.
4.2. Mechanical properties and oxidation resistance
Fig. 9 shows the hardness and crystallite size of different TiSiN
coatings. A maximum hardness of 2816.9 ± 50.4 HV0.02 is obtained for
TiSiN1 coating corresponding to a minimum crystallite size of 17.7 nm.
The hardness and crystallite size for TiSiN3 coating are
2782.7 ± 43.9 HV0.02 and 23.1 nm, respectively. A minimum hardness
of 2677.9 ± 39.1 HV0.02 is obtained for TiSiN2 coating with a max-
imum crystallite size of 33 nm. The hardness is related to the crystallite
size of the TiN which could be explained by the classical Hall-Petch
strengthening [43]. For all the investigated TiSiN coatings in this work,
the hardness is higher than that of TiN (21 GPa [44], around 2100 HV)
and Si3N4 (17 GPa [44], approximately 1700 HV). However, the
Fig. 7. XPS spectra of TiSiN1 coating containing 5.8 at.% Si: (a) Si 2p and (b) N 1 s.
Fig.8. (a) Cross-sectional TEM bright-field image with an inset of SAED pattern and (b) high-resolution TEM micrograph of the as-deposited TiSiN1 coating showing
the nanocomposite structure.
Fig. 9. The hardness and crystallite size of as-deposited TiSiN coatings.
L. Qiu et al. International Journal of Refractory Metals & Hard Materials 80 (2019) 30–39
35
hardness value is lower than that reported by Endler et al. [12] (max-
imum 3700 HV0.01), who deposited the TiSiN coating with the crystal-
lite size of 15 nm and a silicon content between 6 at.% and 8 at.%.
Besides, the hardness is lower than that reported by Vepřek et al.
[3,6,45] for TiSiN coatings deposited by PVD method with a sharp in-
terface between TiN and SiNx.
Table 3 shows the correlation of TiSiN coating hardness with vo-
lume fraction of a-Si3N4,
Si content and grain size. It is indicated that
the volume fraction of a-Si3N4 is low when silicide (eg. TiSi2) was
formed in addition to Si3N4 and TiN even if the Si content is high (e.g.
8.1 at.% in Ref. 12). The smaller grain size leads to a higher TiSiN
coating hardness with a low volume fraction of a-Si3N4 (e.g.< 20%), as
is confirmed from the results of this work and other report [12].
However, a large volume fraction of a-Si3N4 caused by high Si content,
lowers the TiSiN coating hardness even though the grain size is small (5
and 14 nm in Refs. [13, 14], respectively). Additionally, it is found that
PVD TiSiN coating possess higher hardness in comparison with the one
prepared by PACVD when both the a-Si3N4 volume fraction and grain
size are similar. As shown in Table 3, 32% volume fraction of a-Si3N4
with TiN grain size of 5.0 nm results in a hardness of HV 2200 ± 50 for
TiSiN deposited by PACVD [13], while 32.6% volume fraction of a-
Si3N4 with TiN grain size of 7.0 nm leads to a hardness of HV3306.7 for
TiSiN prepared by PVD [40,45]. The lower hardness for TiSiN coating
deposited by PACVD and CVD might be attributed to a few reasons: 1)
higher impurities (O and Cl) than PVD TiSiN coating; 2) diffusion in-
terfaces formed between TiN and a-Si3N4 since the deposition tem-
peratures for PACVD and CVD are usually higher than those of PVD.
According to the hardening mechanism proposed by Koehler [46],
hardness could be enhanced by hindering the movement of dislocations
via the formation of sharp interfaces between several nano-meter thin
epitaxial layers of materials with a large difference in elastic shear
Table 3
Correlation of TiSiN coating hardness with volume fraction of a-Si3N4, Si con-
tent and grain size.
a-Si3N4 (vol
%)
Si content (at.
%)
Grain size
(nm)
Hardness vickers Reference
1.1 8.1a 14.6 3624.3 ± 146 [12]
1.9 0.8b 26.0 2414.8 ± 88.2
4.9 7.0c 14.4 3667.0 ± 134
12.2 5.4 33.0 2677.9 ± 39.1 This workd
12.5 5.6 23.1 2782.7 ± 43.9
13.3 5.8 17.7 2816.9 ± 50.4
32.0e/35.7f 15.3 5.0 2200 ± 50 [13]
55.0g/49.0h 21.0 14.0 1950 ± 50 [14]
7.1 3.0 7.5 3468.8 [40,45]i
11.8 5.0 6.5 3849.5
16.6 7.0 5.0 4287.0
18.8 8.0 4.0 4740.7
23.5 10.0 3.5 4513.9
32.6 14.0 7.0 3306.7
Notes:
aa-Si3N4, TiN and TiSi2 co-exist and their volume fractions were predicted by
thermodynamic calculations.
ba-Si3N4 and TiN co-exist and their volume fractions were predicted by ther-
modynamic calculations.
ca-Si3N4, TiN and TiSi2 co-exist and their volume fractions were predicted by
thermodynamic calculations.
da-Si3N4 and TiN co-exist and their volume fractions were predicted by ther-
modynamic calculations.
e,ga-Si3N4 and TiN co-exist. Si content was converted from weight percentage to
atomic percentage. a-Si3N4 fraction was calculated from HR-TEM image by
software Image J.
f,ha-Si3N4 fraction was predicted from TiSiN coating compositions through
thermodynamic calculations.
iPVD TiSiN coatings. Hardness deviation was not given in the references.
Fig. 10. Schematics of TiSiN nano-composite coatings and hardness correlation with volume fraction of a-Si3N4 and grain size. (a) low fraction of a-Si3N4; (b)
medium fraction of a-Si3N4; (c) high fraction of a-Si3N4; (d) hardness correlation with volume of a-Si3N4 and TiN grain size (data taken from Table 3).
L. Qiu et al. International Journal of Refractory Metals & Hard Materials 80 (2019) 30–39
36
moduli. Atomically sharp interfaces are necessary for superhard het-
erostructured coatings with hardness of ≥40 GPa. In this work, the
TiSiN coatings were deposited at 1123 and 1273 K, and diffuse inter-
faces rather than hetero-structures were obtained, leading to the lower
hardness.
Fig. 10 demonstrates the schematics of TiSiN nano-composite
coatings and hardness correlation with volume fraction of a-Si3N4 and
TiN grain size. With a low volume fraction of a-Si3N4 and a large grain
size of TiN (see Fig. 10a), the coating hardness is low due to the in-
effective hindering of a-Si3N4 for the dislocation movement of TiN
crystallites. The dislocations may pass through the thin amorphous
layers easily and connect with others forming a network of dislocations
under external loading, leading to an earlier failure of TiSiN coating.
With a large amount of a-Si3N4 and a small grain size of TiN (see
Fig. 10c), the TiSiN coating hardness is low as well due to the gliding of
soft amorphous matrix under a certain applied load. Consequently, we
believe a medium volume fraction of a-Si3N4 with medium nano-sized
TiN (see Fig. 10b) is beneficial to enhance the hardness of CVD TiSiN
nano-composite coatings. The discussion for the correlation of hardness
with volume fraction of a-Si3N4 and TiN grain size (data taken from
Table 3) is confirmed as shown in Fig. 10d. An indirect prediction of
CVD TiSiN nano-composite coating hardness becomes possible since the
volume fraction of a-Si3N4, TiN and other phases (TiSi2 and TiSi, etc.)
could be calculated by thermodynamics.
Annealing tests in air were performed to compare the oxidation
resistance of TiN and TiSiN1 coating. TiN coated samples were an-
nealed at 973 K in air for 1 h. TiSiN1 coating samples were annealed at
973, 1023, 1073, 1123 and 1173 K in air for 1 h. After annealing at
973 K, the weight gain for TiN coated sample is 59.5 mg. It is reported
that TiSiN coatings achieve remarkably higher oxidation resistance
than TiN due to the formation of a protecting SiO2 layer acting as an
efficient diffusion barrier against oxygen [47]. This is also confirmed by
our annealing tests on TiSiN1 coating. The weight gains for TiSiN1
coating oxidized at 973, 1023, 1073, 1123 and 1173 K are 0.2, 0.2, 0.9,
3.5 and 107.3 mg, respectively.
Fig. 11 shows the XRD patterns of the annealed and as-deposited
coatings. From Fig. 11a, it is seen that only weak intensity of rutile TiO2
peak presents for TiSiN annealed at 973 K. As the annealing tempera-
ture increases up to 1123 K, the peak intensity of rutile TiO2 is
increasing continuously. When the annealing temperature reaches
1173 K, the peak intensity of rutile TiO2 is reduced while new oxides
WO3 and CoWO4 are observed indicating full oxidation of TiSiN1
coating. All the peaks shift to higher two theta angles due to the tensile
stress. After annealing at 973 K, a remarkable formation of rutile TiO2
and WO3 was observed for TiN coating as shown in Fig. 11b. From the
XRD results, it is indicated that small amount of Si incorporation to TiN
improves the oxidation resistance. TiSiN1 coating with a Si content of
5.8 at.% shows an oxidation resistance up to 973 K. This result is similar
to that reported in the work from Endler et al. [12] indicating that
TiSiN coating with silicon content between 5.5 and 7.7 at. % offers an
oxidation resistance up to 973 K. Meanwhile, it is shown that PVD
coatings with a higher silicon content exhibit a better oxidation re-
sistance up to 1073 K [47].
Fig. 12 shows the as-deposited and oxidized surface morphologies of
TiN and TiSiN1 coatings. Both as-deposited TiN and TiSiN1 coatings
present granular particles on the surface, as shown in Fig. 12a–c. After
annealing at 973 K in air for 1 h, wide cracks appeared on the surface of
TiN coating and the colour of the surface transforms from golden to
dark grey, as shown in Fig. 12b. For TiSiN1 coating, the surface mor-
phology after annealing at 973 K keeps similar to that of as-deposited
state and the colour changes from dark golden to light grey (see
Fig. 12d). When the annealing temperature increases to 1123 K, coarser
granular particles (with small particles adhered to the surface) are
formed on the coating surface, and the surface became light yellow (see
Fig. 12e). The light yellow appearance indicates the formation of WO3,
which confirms the XRD results in Fig. 11. As temperature reaches
1173 K, the TiSiN1 coating is fully oxidized with rod-like oxides formed
on the surface (see Fig. 12f). The oxides are consisted of TiO2, WO3 and
CoWO4 according to the XRD analysis, indicating outward diffusion of
W and Co from cemented
carbide substrate.
5. Conclusion
CVD phase diagrams were established to illustrate the influence of
deposition parameters on the compositions and phases of TiSiN coat-
ings through thermodynamic calculations. It was shown that the de-
position temperature and flow ratio of SiCl4/TiCl4 significantly affect
the atomic fractions of Si, Ti and N in the TiSiN coating prepared from
Fig. 11. XRD patterns of (a) TiSiN1 and (b) TiN oxidized between 973 and 1173 K in air for 1 h.
L. Qiu et al. International Journal of Refractory Metals & Hard Materials 80 (2019) 30–39
37
TiCl4-SiCl4-NH3-H2 gaseous mixtures by low pressure chemical vapor
deposition. Under constant temperature and pressure, the flow rate of
precursors influences the amount of solid phases in TiSiN coating. TiSiN
coatings were successfully deposited with the deposition parameters
selected with the CVD phase diagrams. The atomic fractions of Si, Ti
and N in the TiSiN coatings were measured, and the experimental re-
sults showed a good agreement with thermodynamically calculated
ones.
The microstructure, hardness and oxidation behavior of the TiSiN
coatings were investigated. All the TiSiN coatings consist of nanocrys-
talline TiN and amorphous Si3N4. A maximum hardness of about
2800 HV0.02 and an oxidation resistance up to 973 K were obtained
corresponding to a minimum crystallite size of 17.7 nm and a-Si3N4
volume fraction of 13.3% for coating deposited at 1123 K under
3.0 kPa. A medium volume fraction of a-Si3N4 with medium nano-sized
TiN is proposed to be responsible for enhancing the hardness of CVD
TiSiN nano-composite coatings. Full oxidation of TiSiN coating oc-
curred at 1173 K, resulting in the formation of rutile TiO2, WO3 and
CoWO4. The Si incorporation to TiN significantly improved the oxida-
tion resistance compared to that of TiN which already completely oxi-
dized at 973 K. The presently developed novel strategy of
thermodynamic calculations coupled with key experiments for depos-
iting CVD TiSiN coatings highly efficiently is equally valid for the de-
sign of other CVD coatings.
Acknowledgments
The financial supports from National Natural Science Foundation of
China (Grant no. 51371199) and Key R&D program of Science and
Technology Department of Jiangxi Province in China (Project no.
2018ACH80001) are acknowledged. Mr. Wei Liu and Mr. Qiang Huang
from Achteck are appreciated for the XRD and SEM tests.
References
[1] S.Z. Li, Y.L. Shi, H.R. Peng, Ti-Si-N films prepared by plasma-enhanced chemical
vapor deposition, Plasma Chem. Plasma Process. 12 (1992) 287–297.
[2] S. Veprek, S. Reiprich, L. Shizhi, Superhard nanocrystalline composite materials:
the TiN/Si3N4 system, Appl. Phys. Lett. 66 (1995) 2640–2642.
[3] S. Veprek, A. Niederhofer, K. Moto, T. Bolom, H.-D. Mannling, P. Nesladek,
G. Dollinger, A. Bergmaier, Composition, nanostructure and origin of the ultra-
hardness in nc-TiN/a-Si3N4/a- and nc- TiSi2 nanocomposites with Hv=80 to≥ 105
GPa, Surf. Coat. Technol. 133-134 (2000) 152–159.
[4] S. Veprek, R.F. Zhang, M.G.J. Veprek-Heijman, S.H. Sheng, A.S. Argon, Superhard
Fig. 12. Surface morphology of (a) TiN as-deposited (b) TiN oxidized at 973 K (c) TiSiN1 as-deposited (d) TiSiN1 oxidized at 973 K (e) TiSiN1 oxidized at 1123 K (f)
TiSiN1 oxidized at 1173 K. The inset on the right corner of each image shows the optical view of coating surface. All oxidation tests were performed in air for 1 h.
L. Qiu et al. International Journal of Refractory Metals & Hard Materials 80 (2019) 30–39
38
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0005
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0005
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0010
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0010
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0015
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0015
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0015
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0015
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0020
nanocomposites: origin of hardness enhancement, properties and applications, Surf.
Coat. Technol. 204 (2010) 1898–1906.
[5] S. Veprek, M.G.J. Veprek-Heijman, P. Karvankova, J. Prochazka, Different ap-
proaches to superhard coatings and nanocomposites, Thin Solid Films 476 (2005)
1–29.
[6] S. Veprek, H.-D. Männling, P. Karvankova, J. Prochazka, The issue of the re-
producibility of design superhard nanocomposites with hardness of ≥ 50 GPa, Surf.
Coat. Technol. 200 (2006) 3876–3885.
[7] D.H. Kuo, W.C. Liao, Ti-N, Ti-C-N, Ti-Si-N coatings obtained by APCVD at 650–800
°C, Appl. Surf. Sci. 199 (2002) 278–286.
[8] T. Hira, S. Hayashi, Density and deposition rate of chemically vapour-deposited
Si3N4-TiN composites, J. Mater. Sci. 18 (1983) 2401–2406.
[9] G. Llauro, R. Hillel, F. Sibieude, Elaboration and properties of CVD Ti-N-Si coatings,
Chem. Vap. Depos. 4 (1998) 247–252.
[10] K. Jun, Y. Shimogaki, Development of TiSiN CVD process using TiCl4/SiH4/NH3
chemistry for ULSI anti-oxidation barrier applications, Sci. Technol. Adv. Mater. 5
(2004) 549–554.
[11] J. Perez-Mariano, K.-H. Lau, A. Sanjurjo, J. Caro, D. Casellas, C. Colominas, TiSiN
nanocomposite coatings by chemical vapor deposition in a fluidized bed reactor at
atmospheric pressure (AP/FBR-CVD), Surf. Coat. Technol. 201 (2006) 2217–2225.
[12] I. Endler, M. Höhn, J. Schmidt, S. Scholz, M. Herrmann, M. Knaut, Ternary and
quarternary TiSiN and TiSiCN nanocomposite coatings obtained by chemical vapor
deposition, Surf. Coat. Technol. 215 (2013) 133–140.
[13] F. Movassagh-Alanagh, A. Abdollah-zadeh, M. Asgari, Influence of Si content on the
wettability and corrosion resistance of nanocomposite TiSiN films deposited by
pulsed-DC PACVD, J. Alloys Compd. 739 (2018) 780–792.
[14] F. Movassagh-Alanagh, A. Abdollah-zadeh, M. Aliofkhazraei, M. Abedi, Improving
the wear and corrosion resistance of Ti-6Al-4V alloy by deposition of TiSiN nano-
composite coating with pulsed-DC PACVD, Wear 390-391 (2017) 93–103.
[15] M. Bartosik, R. Hahn, Z.L. Zhang, I. Ivanov, M. Arndt, P. Polick, P.H. Mayrhofer,
Fracture toughness of Ti-Si-N thin films, Int. J. Refract. Met. Hard Mater. 72 (2018)
78–82.
[16] A.O. Eriksson, O. Tengstrand, J. Lu, J. Jensen, P. Eklund, J. Rosén, I. Petrov, Si
incorporation in Ti1-xSixN films grown on TiN (001) and (001)-faceted TiN (111)
columns, Surf. Coat. Technol. 257 (2014) 121–128.
[17] Y.J. Zhang, Y.Z. Yang, H.W. Ding, Y. Peng, S.M. Zhang, L.G. Yu, P.Y. Zhang,
Combining magnetic filtered cathodic arc deposition with ion beam sputtering to
afford superhard TiSiN multilayer composite films with tunable microstructure and
mechanical properties, Vacuum 125 (2016) 6–12.
[18] K.-D. Bouzakis, E. Bouzakis, S. Kombogiannis, R. Paraskevopoulou, G. Skordaris,
S. Makrimallakis, G. Katirtzoglou, M. Pappa, S. Gerardis, R. M'Saoubi,
J.M. Andersson, Effect of silicon content on PVD film mechanical properties and
cutting performance of coated cemented carbide inserts, Surf. Coat. Technol. 237
(2013) 379–389.
[19] S.M. Yang, Y.Y. Chang, D.Y. Wang, D.Y. Lin, W.T. Wu, Mechanical properties of
nano-structured Ti-Si-N films synthesized by cathodic arc evaporation, J. Alloys
Compd. 440 (2007) 375–379.
[20] Y.X. Xu, L. Chen, Z.Q. Liu, F. Pei, Y. Du, Improving thermal stability of TiSiN na-
nocomposite coatings by multilayered epitaxial growth, Surf. Coat. Technol. 321
(2017) 180–185.
[21] S. Veprek, M.J.G. Veprek-Heijman, Industrial applications of superhard nano-
composite coatings, Surf. Coat. Technol. 202 (2008) 5063–5073.
[22] J.H. Hsieh, A.L.K. Tan, X.T. Zeng, Oxidation and wear behaviors of Ti-based thin
films, Surf. Coat. Technol. 201 (2006) 4094–4098.
[23] H. Kashani, M.H. Sohi, H. Kaypour, Microstructure and physical properties of ti-
tanium nitride coatings produced by CVD process, Mater. Sci. Eng. A 286 (2000)
324–330.
[24] C. Czettl, J. Thurner, U. Schleinkofer, Knowledge based coating design of CVD TiN-
TiBN-TiB2 architecture, Int. J. Refract. Met. Hard Mater. 71 (2018)
330–334.
[25] A. Larsson, S. Ruppi, Microstructure and properties of Ti(C,N) coatings produced by
moderate temperature chemical vapour deposition, Thin Solid Films 402 (2002)
203–210.
[26] S. Ruppi, Enhanced performance of α-Al2O3 coatings by control of crystal or-
ientation, Surf. Coat. Technol. 202 (2008) 4257–4269.
[27] J. Todt, R. Pitonak, A. Köpf, R. Weißenbacher, B. Sartory, M. Burghammer,
R. Daniel, T. Schöberl, J. Keckes, Superior oxidation resistance, mechanical prop-
erties and residual stresses of an Al-rich nanolamellar Ti0.05Al0.95N coating prepared
by CVD, Surf. Coat. Technol. 258 (2014) 1119–1127.
[28] M. Arab Pour Yazdi, F. Lomello, J. Wang, F. Sanchette, Z. Dong, T. White,
Y. Wouters, F. Schuster, A. Billard, Properties of TiSiN coatings deposited by hybrid
HiPIMS and pulsed-DC magnetron co-sputtering, Vacuum 109 (2014) 43–51.
[29] L.Y. Du, S.Q. Wang, Y. Du, L.C. Qiu, Z. Chen, X.M. Chen, Z.K. Liu, C. Zhang,
Deposition of CVD-TiCN and TiAlN coatings guided with thermodynamic calcula-
tions, Int. J. Mater. Res. 109 (2018) 277–283.
[30] A. Néron, G. Lantagne, B. Marcos, Computation of complex and constrained equi-
libria by minimization of the Gibbs free energy, Chem. Eng. Sci. 82 (2012) 260–271.
[31] J.O. Andersson, T. Helander, L. Höglund, P.F. Shi, B. Sundman, Thermo-Calc &
DICTRA, computational tools for materials science, Calphad 26 (2002) 273–312.
[32] SGTE, Substance Database, Royal Institute of Technology, Sweden, 1994.
[33] X.Y. Ma, C.R. Li, W.J. Zhang, The thermodynamic assessment of the Ti-Si-N system
and the interfacial reaction analysis, J. Alloys Compd. 394 (2005) 138–147.
[34] M.W. Chase, NIST-JANAF Thermochemical Tables, 4th ed., American Institute of
Physics for the National Institute of Standards and Technology, J. Phys. Chem. Ref.
Data Monographs 9 (1998) 59–1950.
[35] A.T. Dinsdale, SGTE data for pure elements, Calphad 15 (1991) 317–425.
[36] S. Zhang, X.L. Bui, J.R. Jiang, X.M. Li, Microstructure and tribological properties of
magnetron sputtered nc-TiC/a-C nanocomposite, Surf. Coat. Technol. 198 (2005)
206–211.
[37] W.C. Oliver, G.M. Pharr, An improved technique for determining hardness and
elastic modulus using load and displacement sensing indentation experiments, J.
Mater. Res. 7 (1992) 1564–1583.
[38] S. Guha, S. Das, A. Bandyopadhyay, S. Das, B.P. Swain, Investigation of structural
network and mechanical properties of titanium silicon nitride (TiSiN) thin films, J.
Alloys Compd. 731 (2018) 347–353.
[39] D.H. Yu, C.Y. Wang, X.L. Cheng, et al., Microstructure and properties of TiAlSiN
coatings prepared by hybrid PVD technology, Thin Solid Films 517 (2009)
4950–4955.
[40] S. Vepřek, S. Reiprich, A concept for the design of novel superhard coatings, Thin
Solid Films 268 (1995) 64–71.
[41] A. Flink, M. Beckers, J. Sjolen, T. Larsson, S. Braun, L. Karlsson, L. Hultman, The
location and effects of Si in (Ti1-xSix)Ny thin films, J. Mater. Res. 24 (2009)
2483–2498.
[42] G. Greczynski, J. Patscheider, J. Lu, B. Alling, A. Ektarawong, J. Jensen, I. Petrov,
J.E. Greene, L. Hultman, Control of Ti1-xSixN nanostructure via tunable metal-ion
momentum transfer during HIPIMS/DCMS co-deposition, Surf. Coat. Technol. 280
(2015) 174–184.
[43] P.M. Andson, C. Li, Hall-Petch relations for multilayered materials, Nanostruct.
Mater. 5 (1995) 349–362.
[44] H. Holleck, Material selection for hard coatings, J. Vac. Sci. Technol. A4 (6) (1986)
2661–2669.
[45] S. Vepřek, P. Nesládek, A. Niederhifer, F. Glatz, Search for superhard materials:
nanocrystalline composites with hardness exceeding 50 GPa, Nanostruct. Mater. 10
(1998) 679–689.
[46] J.S. Koehler, Attempt to design a strong solid, Phys. Rev. B 2 (1970) 547–551.
[47] J.B. Choi, K. Cho, M.-H. Lee, K.H. Kim, Effects of Si content and free Si on oxidation
behavior of Ti-Si-N coating layers, Thin Solid Films 447–448 (2004) 365–370.
L. Qiu et al. International Journal of Refractory Metals & Hard Materials 80 (2019) 30–39
39
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0020
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0020
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0025
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0025
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0025
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0030
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0030
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0030
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0035
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0035
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0040
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0040
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0045
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0045
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0050
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0050
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0050
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0055
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0055
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0055
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0060
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0060
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0060
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0065
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0065
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0065
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0070
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0070
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0070
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0075
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0075
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0075
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0080
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0080
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0080
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0085
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0085
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0085
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0085
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0090
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0090
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0090
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0090
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0090
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0095
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0095
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0095
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0100
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0100
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0100
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0105
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0105
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0110
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0110
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0115
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0115
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0115
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0120
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0120
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0125
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0125
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0125
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0130
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0130
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0135
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0135
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0135
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0135
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0140
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0140
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0140
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0145
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0145
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0145
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0150
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0150
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0155
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0155
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0160
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0165
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0165
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0170
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0170
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0170
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0175
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0180
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0180
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0180
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0185
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0185
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0185
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0190
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0190
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0190
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0195
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0195
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0195
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0200
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0200
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0205
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0205
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0205
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0210
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0210
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0210
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0210
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0215
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0215
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0220
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0220
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0225
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0225
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0225
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0230
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0235
http://refhub.elsevier.com/S0263-4368(18)30755-8/rf0235
	Mechanical properties and oxidation resistance of chemically vapor deposited TiSiN nanocomposite coating with thermodynamically designed compositions
	Introduction
	Thermodynamic calculations
	Experimental procedure
	Results and discussion
	Composition and morphology of the CVD TiSiN coating
	Mechanical properties and oxidation resistance
	Conclusion
	Acknowledgments
	References