TiSiN Films Research Articles

Structural and tribological properties of TiSiN films with different Si content

TiSiN thin films were deposited on 52100 steel and Al2024 substrates by magnetron sputtering method using Ti and Si targets in Ar+N2 atmosphere. Power values of 40 W, 60 W, and 75 W were applied to the Si target, while the voltage was constant at 370 V for the Ti target. The Si atomic ratios within the film's structure were found to vary in accordance with the increasing Si target power. The impact of varying Si atomic ratios on the structural, mechanical, and tribological properties of the films was investigated. X-ray diffraction, scanning electron microscopy, hardness and wear test methods were performed. As the Si ratio increased from 10 at. % to 20 at. %, the maximum hardness value was 6.06 GPa for 52100 steel and 4.33 GPa for Al2024. With increasing Si content, the film thickness increased from 1.63 µm to 2.05 µm. The lowest surface roughness of the produced films was 0.069 for 52100 steel and 0.308 for Al2024. The lowest wear rate of TiSiN film was calculated at 1.63 × 10−4 mm3/(N.m).

Impact Abrasive Wear Property of CrAlN/TiSiN Multilayer Coating at Elevated Temperatures.

The impact wear property of hard coatings at elevated temperatures is of particular interest for applications in nuclear power plants. This study evaluated the impact wear behavior of two CrAlN/TiSiN coatings with and without sand. Alternately grown CrAlN and TiSiN films with modulation periods of 455 and 19 nm were formed in a columnar structure. The nanomultilayer shows better impact wear resistance than multilayer films with and without sand. The energy absorption rate has a similar trend to wear rate, leading to lower rebound velocity and peak impact force of the nanomultilayer compared with that of the multilayer. CrAlN/TiSiN coatings can protect the 308L substrate from oxidation. The dominant impact wear mechanism without sand is plastic deformation, and this wear region can be defined as the percussive zone. Peeling occurs on the multilayer surface without sand after 104 percussions, leading to rapid oxidation of the 308L substrate at 500 °C. Due to the abrasion effect, the wear rate of the sample with sand increases by an order of magnitude compared to the sample without sand. The wear scar of the sample with sand can be divided into the mixing zone and the sand−affected zone from inside to outside. Fe oxides are formed beyond the unbroken coating, which may be related to the outward diffusion of Fe.

Tribological properties of in-situ PVD TiAlN, TiSiN, and TiAlN/TiSiN coatings under ambient air and vacuum environment

It is known that the interest in manufacturing in a vacuum environment has increased in recent years. Thus, the wear behavior of mechanical tools under vacuum conditions has critical importance. However, adhesion and cold-welding problems between tool and working piece in vacuum conditions lead to poor wear properties and severe coefficient of friction values. Surface treatment methods such as physical vapor deposition coatings can eliminate these undesirable consequences, especially transition metal nitrides. In this study, TiAlN, TiSiN, and TiAlN/TiSiN films were coated on AISI H13 tool steels employing the cathodic arc evaporation technique. Whether the coatings grown to the substrate surface have a positive contribution to the wear performance of the substrate in the ambient air and vacuum environment was answered. Scanning electron microscope, energy dispersive spectrometer, and X-ray diffractometer analyses were used to attain structural properties. The hardness was measured using a nano-hardness tester, and the adhesion properties were determined by a scratch test. The wear behavior of the substrate and coating samples are determined under 2 N constant normal load and using WC-6%Co counter bodies under ambient air and vacuum conditions. The hardness of samples improved owing to surface coatings, and the highest nano-hardness value was determined from the TiSiN coatings as 39.42 GPa, which is ∼700% greater than the substrate. It has been observed that coated samples have superior wear performance in both wear conditions. Besides, it is determined that those tested under a vacuum condition showed superior wear resistance than the samples tested under ambient air. While TiSiN film exhibits the highest wear resistance in ambient air, the TiAlN/TiSiN layer is the best in a vacuum environment. Owing to the deposited coatings, the seizure mechanism between the friction surfaces, which is frequently encountered in the vacuum environment, is prevented, and a fascinating improvement in terms of friction coefficient is achieved.

Microstructure and tribomechanical properties of multilayer TiZrN/TiSiN composite coatings with nanoscale architecture by cathodic-arc evaporation

Multilayer TiZrN/TiSiN coatings were deposited on steel substrate by the cathodic-arc evaporation technique. The TiZr (75:25 at. %) and TiSi (95:5 at. %) alloy cathodes served as evaporation sources. Scanning electron microscopy with energy-dispersive spectroscopy, secondary ion mass-spectrometry, X-ray diffraction and X-ray photoelectron spectroscopy were employed to investigate the microstructure, elemental composition, phase state and bonding structure of the deposited coatings. Nanoindentation and ball-on-disk tribology tests were used to measure the mechanical and tribological features of the coatings, such as hardness, elastic modulus, toughness, friction coefficient and wear rate. The results show that all multilayers were fcc structures with a strong preferred orientation along (111) plane. The coherent growth of the multilayers contributed to the formation of the fine-grained structure with crystallites of 9.2–11.6 nm size and a low level of residual stresses of− (3.5–5.3) GPa. All multilayer coatings exhibited high hardness up to 38.2 ± 1.15 GPa and elastic modulus up to 430 ± 12.9 GPa, indicating higher resistance against plastic deformation compared to TiZrN and TiSiN films. The result of ball-on-disk wear tests showed that the multilayer sample with the best structural features (modulation period of 20.4 nm, 0.86 at. % of Si, the crystallite size of 9.2 nm and residual stress of− 3.5 GPa) demonstrated the lowest friction coefficient of 0.844 and better wear rate of 3.32·10–5 mm3/N m.

High temperature tribological behaviour of TiSiN(Ag) films deposited by HiPIMS in DOMS mode

Self-lubricant coatings offer an opportunity to increase tool lives in dry machining operations for hard-to-cut materials. In this work, TiSiN(Ag) coatings were deposited to assess the influence of silver in the tribological behaviour at high temperatures. Two types of counterparts were used: 6 mm diameter Al2O3 and TiAl6V4 balls. RT tests conducted against Al2O3 balls showed that silver slightly decreases the friction but deteriorates the wear resistance. Wear resistance is improved when the temperature is increased to 600 °C, when compared to RT tests. Tribology tests against TiAl6V4 balls showed that silver has a beneficial effect in the reduction of friction and wear. Additionally, silver hinders the adhesion of material to the wear track. Temperature also plays an important role in propelling the effects of silver.

High Si content TiSiN films with superior oxidation resistance

The high-temperature oxidation resistance of Ti1-xSixN films with Si content varying in wide range, 0.13 ≤ x ≤ 0.91, is evaluated. Films are grown in Ar/N2 atmospheres using a hybrid high-power impulse and dc magnetron sputtering (HiPIMS/DCMS) configuration with Si target powered by HiPIMS and Ti target operated in DCMS mode. The substrate bias is synchronized to the Si+-rich portions of the HiPIMS pulses in order to promote solid solution formation. A combination of X-ray photoelectron spectroscopy, elastic recoil detection analysis, and cross-sectional scanning electron microscopy reveals a sharp increase in the oxidation resistance for layers with x > 0.50. The thickness of the oxide layer, following 1 h anneal at 800 °C in air, is in the range 150–200 nm for 0.13 ≤ x ≤ 0.50 and decreases to only 4 nm with x = 0.91, which is ~30 times lower than for the best performing Ti1-xAlxN film (x = 0.64) tested under the same conditions. The oxide forming on top of Ti1-xSixN films with x ≥ 0.41 consists of a SiO2-TiO2 two-phase mixture with a molar ratio given by Si/Ti ratio. In Ti1-xSixN layers with x ≤ 0.31, the presence of grain boundaries, which act as diffusion paths facilitates Si diffusion towards the bulk of the film resulting in that TiO2, the thermodynamically more stable oxide, terminates the surface. Ti0.09Si0.91N films, are essentially unaffected by the anneal and exhibit a hardness of 23 GPa, which is ~30% higher than for the reference SiNz film. Moreover, we demonstrate that 25 nm thick Ti0.09Si0.91N capping layers successfully prevent Ti0.36Al0.64N oxidation at 800 °C. Such approach provides superior oxidation protection compared to alloying TiAlN with Si. Our results suggest that multilayers including nm thin layers of high Si-content TiSiN is a most effective approach to improve high-temperature oxidation resistance of functional ceramic thin films.

The effect of phase on microstructure and mechanical performance in TiAlN and TiSiN films

To study the effect of phase on the microstructure and mechanical properties of nitride coatings, three films of TiN, TiAlN, and TiSiN were prepared on the surface of high-speed steel using hollow cathode assisted multi-arc ion plating technique. The XRD lines of the three films were analyzed and calculated by linear analysis. The element and phase of the film were observed and analyzed by x-ray Diffraction (XRD), Transmission Electron Microscope (TEM), energy dispersive x-ray analysis (EDS). The microstructure and film thickness of the coating were characterized by scanning electron microscopy (SEM). The surface roughness of the film was observed by Confocal laser scanning microscope (CLSM). The hardness, friction coefficient, and coating/substrate adhesion of the film were tested by the G200 nanometer hardness tester and CETR UNMT-1 surface micro-nano mechanical test system. We discovered two different reinforcement mechanisms. The high microscopic strain value (1.309 × 10−3) in the TiAlN film was related to the formation of Ti3AlN substitutional solid solution in the film formed a large lattice distortion,however, the coating/substrate adhesion (33.5 N) was lowered. The result of independent nucleation and growth of the Si3N4 phase in the TiSiN film refines the structure of the film, alleviating the increase of microscopic strain. At this time, the coating/substrate adhesion reaches the highest value of 40 N and the film surface roughness reaches the minimum value of 0.451 μm. The results also show that the TiSiN coating can obtain good coating/substrate adhesion without pre-plating.

Oxidation behaviour of TiSiN(Ag) films deposited by high power impulse magnetron sputtering

TiSiN coatings alloyed with increasing silver content were deposited for designing a self-lubricant coating with controlled lubricant element diffusion. Here, we report the influence of the Ag content on the oxidation behaviour of TiSiN(Ag) films deposited by HiPIMS (High Power Impulse Magnetron Sputtering) working in DOMS (Deep Oscillation Magnetron Sputtering) mode. In-situ high-temperature oxidation X-ray diffractograms allowed to observe the first signs of oxidation occurring at about ~ 850 °C with the appearance of the rutile TiO2 peaks. Observation of even distribution of silver was still possible on the un-oxidized part of the films, suggesting that the films offer an efficient barrier to the Ag diffusion. Dynamic-mode thermogravimetry analysis showed that silver addition does not change the onset point of oxidation of the coatings. However, the oxidation rate deteriorated with the presence of Ag. An unusual mass loss could be observed for the coatings with 6 and 10 at.% of Ag, as a result of silver evaporation/sublimation process. Results from isothermal thermogravimetry performed at 900 °C show two distinct regimes and corroborate the detrimental effect of the Ag on the oxidation resistance of the coatings. Nonetheless, in the un-oxidized part of the films, the silver continued to be homogeneously distributed confirming again the efficient barrier against Ag diffusion.

Substrate Mediated Synthesis of Ti–Si–N Nano‐and‐Micro Structures for Optoelectronic Applications

Being one of the strongest materials, ternary TiSiN exhibits a very interesting family of binary transition metal nitride and silicide systems. A novel technique to fabricate morphologically fascinating nano and micro structures of TiSiN is reported here. The referred TiSiN films, majorly constituted with cubic TiN phase, are enriched with crystalline nanoparticles, micro‐flowers, and faceted micro‐crystals which possess attractive functionalities toward plasmon mediated optoelectronic applications. Reactivity of titanium to silicon nitride‐based dielectric topping on the substrate at high temperature plays the key role in nitride formation for the demonstrated protocol. The optoelectronic response for these morphologically enriched composite films indicates an influential role of photo‐induced surface plasmon polaritons (SPPs) on their dc transport properties. A plasmonically tuned resistive switching, controlled by the surface morphology in association with the film thickness, is observed under light illumination. Using Drude's modified frequency dependent bulk electron scattering rates and surface mediated SPPs‐electron scattering rates, a generic model is proposed for addressing unambiguously the increased device resistance in response to light. The featured synthesis process opens a new direction toward the growth of transition metal nitrides while the proposed model serves as a basic platform to understand photo‐induced electron scattering mechanisms in metal.

TiSiN(Ag) films deposited by HiPIMS working in DOMS mode: Effect of Ag content on structure, mechanical properties and thermal stability

TiSiN(Ag) coatings with Ag contents ranging from 0 to 29 at.% were designed as promising materials to allow long term solid lubrication during dry machining operations. Here, we report the influence of Ag additions on the properties of TiSiN(Ag) films deposited by high power impulse magnetron sputtering- HiPIMS, working in deep oscillation magnetron sputtering mode – DOMS. Introduction of silver pellets on the target progressively increases the Ag concentration on the films, influencing the deposition rate, structure and morphology of the films. All the coatings display crystalline peaks assigned to a TiN fcc NaCl type structure. Ag additions to the reference TiSiN film, significantly broadens the TiN diffraction peaks and abruptly decreases the grain size of the TiN crystallites from 24 nm to 11–7 nm. Grain size was then found to be independent of the silver content on the films. Hardness and Young's modulus of the coatings decreased with increasing Ag additions mainly due to the increase of this soft phase on the microstructure. An increase in the peak power was observed when 6 at.% Ag was added which revealed a transition from a columnar to a very compact morphology, a decrease of the deposition rate and an increase of the lattice parameter for this coating. A reverse in the morphology is then perceived for the higher Ag concentration (29 at.%). Annealing treatment didn't present any significant changes in the structure/phase composition or mechanical properties of the coatings. Elemental maps and profiles allowed perceiving the formation of a very thin dual layer where a top Ag rich layer is formed due to the diffusion of silver from the Ag deficient TiSiN layer below.

Self-lubricating TiSi(V)N thin films deposited by deep oscillation magnetron sputtering (DOMS)

In last years, vanadium containing coatings have been introduced as possible candidates for self-lubrication due to their good tribological properties. The main objective of the present work was to investigate the effect of V addition on the morphology, structure, and tribological performance at room temperature of Ti-Si-N films deposited by high power impulse magnetron sputtering (HiPIMS) in deep oscillation magnetron sputtering mode (DOMS) with two different peak powers. All coatings showed a fcc NaCl-type structure. A shift of the diffraction peaks to higher diffraction angles was observed with increasing V content, suggesting the formation of a substitutional solid solution of V in the TiN phase. However, depending on the peak power, different preferred orientations and morphologies were achieved. Independently of the V content in the coatings, low peak power promoted a [111] preferred orientation and a columnar morphology, while high peak power favored the [200] preferred orientation and a compact morphology. V additions had a beneficial effect on the tribological behavior of the coatings by decreasing the wear rate and the friction coefficient of the TiSiN films. Abrasive wear was found to be the main wear active mechanism taking place on the reference Ti-Si-N films, while polishing wear took place in V rich coatings. The improved tribological properties of the V-containing coatings were attributed to the formation of the lubricious V2O5 on the wear track.

Microstructure and mechanical property of TiSiN nanocomposite film with inserted CrAlN nanomultilayers

Abstract A series of TiSiN films inserted by CrAlN nanomultilayers with different thicknesses was prepared by reactive magnetron sputtering. The influences of CrAlN layer thickness on the microstructure and hardness of films were investigated by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and nano-indentation techniques. The insertion of CrAlN nanomultilayers destructs the nanocomposite structure of TiSiN film, leading to the decrease of hardness. As the CrAlN layer thickness increases to 2.5 nm, CrAlN layers are inclined to grow epitaxially with TiSiN layers in order to lower the interfacial energy. As a result, the TiSiN film can be further strengthened with the maximal hardness of 53.9 GPa. As the CrAlN layer thickness further increases to 3.0 nm, the epitaxial growth structure between TiSiN and CrAlN layers is broken, resulting in the deterioration of hardness.

Corrosion Behavior of TiSiN Coatings Deposited on Ni-Cr Alloy in Artificial Saliva with and without Fluoride

TiSiN thin films were deposited on NiCr dental alloy in order to enhance the corrosion resistance in artificial saliva with and without fluoride content. The TiSiN films were prepared using reactive cathodic arc method at two different substrate bias voltages (-50 V and-200 V). For the corrosion evaluation, artificial saliva with pH=5.2 was chosen, because this is a critical value for mineral dissolution of dental tissue which can affect the dental alloys. A content of 0.1 % NaF was added to the artificial saliva to simulate the effect of fluoride based hygiene products. The TiSiN coated NiCr alloys exhibited a higher corrosion resistance than the NiCr substrate, irrespective of the testing environment. The best corrosion resistance was found for the TiSiN deposited at-200 V.

Growth of high-density carbon nanotube forests on conductive TiSiN supports

We grow vertically aligned carbon nanotube forests on refractory conductive films of TiSiN and achieve area densities of (5.1 ± 0.1) × 1012 tubes cm−2 and mass densities of about 0.3 g cm−3. The TiSiN films act as diffusion barriers limiting catalyst diffusion into the bulk of the support, and their low surface energy favours catalyst de-wetting, inducing forests to grow by the root growth mechanism. The nanotube area density is maximised by an additional discontinuous AlOx layer, which inhibits catalyst nanoparticle sintering by lateral surface diffusion. The forests and the TiSiN support show ohmic conduction. These results suggest that TiSiN is the favoured substrate for nanotube forest growth on conductors and liable of finding real applications in microelectronics.

Tailoring the nanostructure of Ti–Si–N thin films by HiPIMS in deep oscillation magnetron sputtering (DOMS) mode

Nanocomposite TiSiN films consist of nano-sized TiN crystallites surrounded by an amorphous Si–N matrix. Many works have shown that the hardness of nanostructured TiSiN films increases with increasing silicon content up to an optimal concentration. However, energetic ion bombardment of the growing film also influences the hardness and structure of TiSiN films. The main objective of the present work was to tailor the nanostructure of TiSiN films by using the highly ionized fluxes of sputtered material generated in a HiPIMS discharge. For this purpose TiSiN films were deposited by DOMS (deep oscillation magnetron sputtering) mode. The energetic ion bombardment of the growing films was controlled by changing the peak power.The crystal structure of TiSiN films was analyzed by X-ray diffraction (XRD) with a parallel beam in both θ–2θ and GIXRD geometries. EDS and XPS were used to elucidate the chemical composition of the films and the nature of the chemical bonding, respectively. The microstructure of the films was characterized by SEM while their mechanical properties were measured by nanoindentation.All the films deposited by DOMS have a nanocomposite microstructure consisting of two phases: f.c.c TiN and a-SiN. Although similar amounts of SiN were detected in the films, both the phase distribution and the properties of the f.c.c phase depend on the peak power. Two deposition regimes were identified. At low peak power (up to 44kW) the growing film is bombarded with a high flux of low energy ionized sputtered species promoting the surface mobility of the ad-atoms and avoiding the atomic peening effect. At high peak power the energetic species impinging on the substrate are able to penetrate in the sub-surface of the growing film, resulting in an intense atomic peening effect which ultimately leads to secondary nucleation due to the high number of defects.

Tribological properties of self-lubricating TiSiVN coatings at room temperature

In the last years, vanadium rich coatings have been introduced as possible candidates for self-lubrication due to their optimum tribological properties. In the present investigation, the influence of V incorporation on the wear performance of TiSiN films deposited onto WC substrates by d.c. reactive magnetron sputtering is reported. The results achieved for TiSiVN films were compared and discussed in relation to Ti0.80Si0.15N, TiN and Ti0.82V0.15N coatings prepared as references. The tribological properties of the coatings were evaluated at room temperature on a pin on disk tribometer equipment using two different counterparts: Al2O3 and HSS balls. The wear tracks, ball-wear scars and wear debris were characterized by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM–EDS). Tribological tests indicated that the wear rate and the friction coefficient of Ti0.80Si0.15N coating decreased with continuous increase of V content being the overall behavior strongly dependent on the counterpart ball material. For Al2O3 balls the wear rate and friction coefficient of coatings were much lower compared to sliding against HSS steel balls. Ti0.80Si0.15N showed the lowest wear resistance among all tested coatings, independently of the counter-body. For V rich coatings tested with Al2O3 balls the polishing wear mechanism was observed, whereas adhesion wear took place when tested against HSS balls.

Effect of Substrate Temperature on the Properties of Hafnium Nitride Films Prepared by DC Sputtering

Hafnium Nitride (HfN) thin films were fabricated by sputtering technique reaching a thickness of 250 nm. The substrate temperature was varied in 25, 100, 200, 300, 400 and 500 °C. Hardness, coefficient of friction, electrical resistivity and corrosion behavior of HfN thin films were studied. The structural changes were analyzed by X ray diffraction (XRD). The film growth at room temperature showed the highest hardness value (15.8 GPa), higher electrical resistivity (1.23´1013 mW-cm) and the lowest coefficient of friction (0.37), as well as the best polarization resistance. Increased substrate temperature tends to decrease the corrosion resistance (icorr: 17.50 nA/cm2 to 254.9 nA/cm2) and friction coefficient (0.37 to 0.58), however, all values are above of corrosion resistance and friction coefficient reported by TiSiNO and TiSiN films. Images of scanning electron microscopy (SEM) show that films presented low surface damage with no evidence of corrosion products.

Si incorporation in Ti1 − xSixN films grown on TiN(001) and (001)-faceted TiN(111) columns

Thin films consisting of TiN nanocrystallites encapsulated in a fully percolated SiNy tissue phase are archetypes for hard and superhard nanocomposites. Here, we investigate metastable SiNy solid solubility in TiN and probe the effects of surface segregation during the growth of TiSiN films onto substrates that are either flat TiN(001)/MgO(001) epitaxial buffer layers or TiN(001) facets of length 1–5nm terminating epitaxial TiN(111) nanocolumns, separated by voids, deposited on epitaxial TiN(111)/MgO(111) buffer layers. Using reactive magnetron sputter deposition, the TiSiN layers were grown at 550°C and the TiN buffer layers at 900°C. On TiN(001), the films are NaCl-structure single-phase metastable Ti1−xSixN(001) with N/(Ti+Si)=1 and 0≤x≤0.19. These alloys remain single-crystalline to critical thicknesses hc ranging from 100±30nm with x=0.13 to 40±10nm with x=0.19. At thicknesses h>hc, the epitaxial growth front breaks down locally to form V-shaped polycrystalline columns with an underdense feather-like nanostructure. In contrast, the voided epitaxial TiN(111) columnar surfaces, as well as the TiN(001) facets, act as sinks for SiNy. For Ti1−xSixN layers with global average composition values 〈x〉=0.16, the local x value in the middle of Ti1−xSixN columns increases from 0.08 for columns with radius r⋍2nm to x=0.14 with r⋍4nm. The average out-of-plane lattice parameter of epitaxial nanocolumns encapsulated in SiNy decreases monotonically with increasing Si fraction 〈x〉, indicating the formation of metastable (Ti,Si)N solid solutions under growth conditions similar to those of superhard nanocomposites for which the faceted surfaces of nanograins also provide sinks for SiNy.

RETRACTED: Correlation of the Transition Metal Compound Ternary Nitride Thin Films

Thin films of MXN (M stands for early transition metal and X = Si, Ge, Sn) are studied as protective coatings. To extend the knowledge about the formation of nanocomposite films, various MXN systems have been compared. TiSiN, TiGeN, TiSnN, NbSiN, ZrSiN and CrSiN thin films were deposited by reactive magnetron sputtering, from confocal targets in a mixed Ar/N2 atmosphere. The chemical reactivity of germanium and tin with nitrogen is significantly lower than that of Si and Ti. Therefore, the TiGeN and TiSnN systems are different from TiSiN. Important changes in the morphology and structure of MXNfilms are induced by X addition. Nanocrystalline composite films are formed in all these investigated ternary systems.

Influence of TiN-nanolayered insertions on microstructure and mechanical properties of TiSiN nanocomposite film

TiN nanolayers with different thicknesses were inserted in TiSiN nanocomposite film by magnetron-sputtering technique. The influences of TiN insertion nanolayers with different thicknesses on microstructure and mechanical properties of TiSiN film were investigated X-ray diffraction, high-resolution transmission electron microscopy, scanning electron microscopy, and nanoindentation techniques. When the TiN insertion layer thickness is <0.5 nm, TiN nanolayers can coordinate the misorientations between TiN nanocrystallites in adjacent TiSiN layers, leading to the transformation from the nanocomposite structure with TiN nanocrystallites encapsulated by SiN x interfacial phase into columnar crystal structure, and disappearance of the strengthening effect from the nanocomposite structure. When the TiN insertion layer thickness increases to 1.0 nm, the film is strengthened with the epitaxial growth structures between TiSiN and TiN layers. As the TiN insertion layers further thicken, the hardness and elastic modulus evidently decrease, which can be attributed to the breakage of epitaxial growth structures between TiSiN and TiN layers.