Low Compressive Stress Research Articles

Time-averaged and time-resolved ion fluxes related to reactive HiPIMS deposition of Ti-Al-N films

Time-averaged and time-resolved ion fluxes during reactive HiPIMS deposition of Ti1-xAlxN thin films are thoroughly investigated for the usage of Ti1-xAlx composite targets – Al/(Ti + Al) ratio x = 0.4 and 0.6. Ion mass spectroscopy analysis revealed, that increasing x in the target material or reducing the N2 flow-rate ratio leads to a proportional increase of the Al+-ion count fraction, whereas that of Tin+-ions (n = 1, 2) remains unaffected despite of comparable primary ionisation energies between Al and Ti. In fact, energetic Ti2+-ions account for the lowest flux fraction incident on the substrate surface, allowing for a high Al-solubility limit in cubic-structured Ti1-xAlxN thin films (xmax ~ 0.63) at low residual stresses. In addition, time-resolved plasma analysis highlights the simultaneous arrival of metal- and process-gas-ions throughout the entire HiPIMS pulse duration. These ion-bombardment conditions, which were dominated by gas-ion irradiation with a significant contribution of Al+-ions (up to ~20 %) and negligible energetic Ti2+-ions, allowed for the growth of cubic Ti0.37Al0.63N coatings exhibiting high indentation hardness of up to ~36 GPa at a low compressive stress level (σ = −1.3 GPa).

Stishovite nucleation at low shock pressures in soda-lime glass

Highly dense and ultra-hard Stishovite phase is the most stable form of SiO2. It is formed when fused silica is subjected to extreme pressures (>34 GPa). In this communication, we report nucleation of the Stishovite phase in shock-loaded soda-lime glass (SLG) samples at a remarkably low compressive stress of 7 GPa. Although it falls within the reported Hugoniot Elastic Limit of SLG between 2.5 and 7 GPa, it is significantly below the crystallization threshold of 34 GPa observed for fused silica. SLG plates were shock loaded by impacting them at 1–2.5 km/s using a table-top experimental setup in which 1 mm-dia Al micro flyer plates of 25–50 μm thickness were generated and propelled using a top-hat Nd:YAG laser pulse of 8 ns duration. The shocked samples were imaged using High Resolution Transmission Electron Microscopy (HRTEM) and further analyzed using Selected Area Electron Diffraction and FFT analyses. All samples showed nucleation of 4 nm Stishovite crystals distributed within the amorphous SLG matrix. The stress state was determined by directly measuring the flyer speed, particle velocity, and shockwave speed by using a state-of-the-art Photonic Doppler Velocimeter (PDV).

Giant low-field actuated caloric effects in a textured Ni43Mn47Sn10 alloy

In this work, based on composition adjusting and texture control, we demonstrate giant elastocaloric and magnetocaloric effects in a directionally solidified Ni43Mn47Sn10 polycrystalline with strong <001>A texture. On removing a low compressive stress of 210 MPa, giant adiabatic temperature change up to −17.3 K is achieved. Such value is much higher than those in some elastocaloric materials reported previously. Besides, giant magnetic field induced entropy changes of 23.5 Jkg−1K−1 and 37.1 Jkg−1K−1 are also obtained under the magnetic field changes of 2 T and 5 T, respectively. Simultaneously achieving giant elastocaloric and magnetocaloric effects actuated by relatively low external field is of great importance to explore multi-caloric or coupled caloric effects in developing efficient and eco-friendly solid-state refrigeration technology.

Low temperature growth of stress-free single phase α-W films using HiPIMS with synchronized pulsed substrate bias

Efficient metal-ion-irradiation during film growth with the concurrent reduction of gas-ion-irradiation is realized for high power impulse magnetron sputtering by the use of a synchronized, but delayed, pulsed substrate bias. In this way, the growth of stress-free, single phase α-W thin films is demonstrated without additional substrate heating or post-annealing. By synchronizing the pulsed substrate bias to the metal-ion rich portion of the discharge, tungsten films with a ⟨110⟩ oriented crystal texture are obtained as compared to the ⟨111⟩ orientation obtained using a continuous substrate bias. At the same time, a reduction of Ar incorporation in the films are observed, resulting in the decrease of compressive film stress from σ = 1.80–1.43 GPa when switching from continuous to synchronized bias. This trend is further enhanced by the increase of the synchronized bias voltage, whereby a much lower compressive stress σ = 0.71 GPa is obtained at Us = 200 V. In addition, switching the inert gas from Ar to Kr has led to fully relaxed, low tensile stress (0.03 GPa) tungsten films with no measurable concentration of trapped gas atoms. Room-temperature electrical resistivity is correlated with the microstructural properties, showing lower resistivities for higher Us and having the lowest resistivity (14.2 μΩ cm) for the Kr sputtered tungsten films. These results illustrate the clear benefit of utilizing selective metal-ion-irradiation during film growth as an effective pathway to minimize the compressive stress induced by high-energetic gas ions/neutrals during low temperature growth of high melting temperature materials.

Monolithic Germanium-Tin Pedestal Waveguide for Mid-Infrared Applications

Germanium-tin (GeSn) is a CMOS-compatible group-IV material. Its growth, however, is plagued by the tendency of Sn segregation and the generation of defects within the GeSn layer when it is grown on the lattice-mismatched substrate. Thus far, thin GeSn has been reported for use in a direct-band gap for near-mid infrared light source and photodetector. In this communication, we report the growth of high quality single-crystalline GeSn (∼ 1 μm) with low compressive stress (−0.3%) and low defects (3 × 107 /cm2) on Ge buffer on Si substrate. The as-grown GeSn is then fabricated into pedestal waveguide of width 1.25 μm. An estimated propagation loss of 1.81 dB/cm and bending loss of 0.19 dB/ bend are measured at 3.74 μm. In the absence of Ge-O absorption peaks at 820 and 550 cm−1, under optimal fabrication and measurement condition, the proposed GeSn waveguide might possibly support light propagation for wavelength beyond 25 μm.

Plasticity characterization of certain Nigeria clay minerals for their application in ceramic water filters.

Plasticity is an essential property of clay that determines its suitability for water filtration. There are no published works on the plastic behavior of clays from the study locations. The plastic behavior of seven Nigerian clays was examined using plasticity indices and compressive stress parameters in relation to chemical compositions and moisture content. The objective is to determine plastic behavior of some Nigerian clays and their suitability in production of Expanded Clay Aggregates (ECA) for water filters. Compressive stresses and deformation parameters were determined experimentally and compared theoretically. Atterberg limits (D 4318) were used to determine the plasticity indices. Chemical compositions of the samples were examined with XRF and correlated with plasticity and mineral contents of the clays. The clays are aluminosilicates with SiO2/Al2O3 ratio of 1.61 to 3.03 and plastic indices of 8 to 49. Low plastic indices (8-11) and low compressive stresses parameters were observed for kaolinite clays (0.002 MPa) due to their low affinity for water while zeolite rich clays showed high plastic indices (46 and 49) for Obowo and Minna and sharp difference in their compressive stresses parameters (0.15 and 0.03 MPa) at optimum moisture contents of 57% and 53%, respectively. Despite varying moisture content, chemical and mineral compositions, all curves showed similar trends apart from kaolinites at 40% moisture content. Relationships exist among microstructural properties, chemical composition, moisture content, compressive strength, and plasticity indices of the clays. The plastic behaviors show they are suitable for development of ECA for water filters.

Targeted adjustment of residual stresses in hot-formed components by means of process design based on finite element simulation

The aim of this work is to generate an advantageous compressive residual stress distribution in the surface area of hot-formed components by intelligent process control with tailored cooling. Adapted cooling is achieved by partial or temporal instationary exposure of the specimens to a water–air spray. In this way, macroscopic effects such as local plastification caused by inhomogeneous strains due to thermal and transformation-induced loads can be controlled in order to finally customise the surface-near residual stress distribution. Applications for hot-formed components often require special microstructural properties, which guarantee a certain hardness or ductility. For this reason, the scientific challenge of this work is to generate different residual stress distributions on components surfaces, while the geometric as well as microstructural properties of AISI 52100 alloy stay the same. The changes in the residual stresses should therefore not result from the mentioned changed component properties, but solely from the targeted process control. Within the scope of preliminary experimental studies, tensile residual stresses in a martensitic microstructure were determined on reference components, which had undergone a simple cooling in water (from the forming heat), or low compressive stresses in pearlitic microstructures were determined after simple cooling in atmospheric air. Numerical studies are used to design two tailored cooling strategies capable of generating compressive stresses in the same components. The developed processes with tailored cooling are experimentally realised, and their properties are compared to those of components manufactured involving simple cooling. Based on the numerical and experimental analyses, this work demonstrates that it is possible to influence and even invert the sign of the residual stresses within a component by controlling the macroscopic effects mentioned above.

Mechanical properties and adhesion behavior of amorphous carbon films with bias voltage controlled TixCy interlayers on Ti6Al4V

Amorphous carbon is a promising functional film material to enhance the surface properties of Ti-based alloys for orthopaedic applications. However, high adhesion of the amorphous carbon film on the orthopaedic implants is essential to fully exploit its potential under high load bearings. Interlayer films are generally employed to improve the adhesion. The applied bias voltage is a decisive deposition parameter and significantly influences the structure and mechanical properties during the interlayer growth, which in turn affect the properties of the amorphous carbon film. Therefore, chemically graded titanium carbide (TixCy) interlayers were deposited using bias voltages of −50, −100, and −150 V with a subsequent hydrogen-free amorphous carbon (a-C) top layer on Ti6Al4V by magnetron sputtering. The mechanical properties and adhesion behavior of single TixCy interlayers were evaluated to analyze the interaction effect of TixCy on bilayered TixCy/a-C structures.A high bias voltage generates dense TixCy of a more disordered and defected structure with high stresses, high hardness of ~16 GPa, and high elastic modulus of ~170 GPa. However, high compressive stresses provoke a low adhesion strength, while low compressive stresses ensure a good adhesion behavior of TixCy. Highly stressed TixCy interlayers lead to overall higher stresses for the entire TixCy/a-C film. Independently of TixCy, the a-C top layer exhibits hardness and elastic modulus values of ~16 and ~160 GPa, respectively. The TixCy/a-C films with TixCy interlayers deposited at high bias voltages possess a low adhesion strength, while a lower bias voltage favors a good adhesion of TixCy/a-C on Ti6Al4V. Therefore, a moderate bias voltage is crucial to deposit lowly stressed TixCy interlayers, which ensure a high adhesion of TixCy/a-C on Ti6Al4V. Consequently, the bias voltage allows controlling the mechanical properties and adhesion behavior of the interlayer and, hence, the adhesion strength of the entire amorphous carbon film structure on Ti-based alloys for orthopaedic applications.

Temperature Dependence of Stress and Optical Properties in AlN Films Grown by MOCVD.

AlN epilayers were grown on a 2-inch [0001] conventional flat sapphire substrate (CSS) and a nano-patterned sapphire substrate (NPSS) by metalorganic chemical vapor deposition. In this work, the effect of the substrate template and temperature on stress and optical properties of AlN films has been studied by using Raman spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-visible spectrophotometer and spectroscopic ellipsometry (SE). The AlN on NPSS exhibits lower compressive stress and strain values. The biaxial stress decreases from 1.59 to 0.60 GPa for AlN on CSS and from 0.90 to 0.38 GPa for AlN on NPSS sample in the temperature range 80–300 K, which shows compressive stress. According to the TEM data, the stress varies from tensile on the interface to compressive on the surface. It can be deduced that the nano-holes provide more channels for stress relaxation. Nano-patterning leads to a lower degree of disorder and stress/strain relaxes by the formation of the nano-hole structure between the interface of AlN epilayers and the substrate. The low crystal disorder and defects in the AlN on NPSS is confirmed by the small Urbach energy values. The variation in bandgap (Eg) and optical constants (n, k) with temperature are discussed in detail. Nano-patterning leads to poor light transmission due to light scattering, coupling, and trapping in nano-holes.

Fabrication and evaluation of suspended Micro‐heater using TiN

AbstractIn this study, suspended micro‐heater using TiN for decreasing power dissipation was fabricated and evaluated. The self‐supporting film of the suspended filament was developed by the low compressive stress SiO2 film deposited by the dc reactive sputtering method with rf substrate bias and the post annealing at 900°C. In the suspended structure process, single photolithography process and two wet etching process of HF and KOH solution were used. The power dissipation of the suspended heaters was obtained about 70 mW and it is indicated that the power dissipation is able to reduce than the other structure in previous research. Then, it is expected that the TiN micro‐heater using suspended structure is applicable to several MEMS sensors.

Compression and tension behavior of the prosthetic foam materials polyurethane, EVA, Pelite™ and a combination of polyurethane and EVA: a preliminary study.

Materials with low-strength and low-impedance properties, such as elastomers and polymeric foams are major contributors to prosthetic liner design. Polyethylene-Light (Pelite™) is a foam liner that is the most frequently used in prosthetics but it does not cater to all amputees' limb and skin conditions. The study aims to investigate the newly modified Foam Liner, a combination of two different types of foams (EVA+PU+EVA) as the newly modified Foam Liner in terms of compressive and tensile properties in comparison to Pelite™, polyurethane (PU) foam, and ethylene-vinyl acetate (EVA) foam. Universal testing machine (AGS-X, Shimadzu, Kyoto, Japan) has been used to measure the tensile and compressive stress. Pelite™ had the highest compressive stress at 566.63kPa and tensile stress at 1145kPa. Foam Liner fell between EVA and Pelite™ with 551.83kPa at compression and 715.40kPa at tension. PU foam had the lowest compressive stress at 2.80kPa and tensile stress at 33.93kPa. Foam Liner has intermediate compressive elasticity but has high tensile elasticity compared to EVA and Pelite™. Pelite™ remains the highest in compressive and tensile stiffness. Although it is good for amputees with bony prominence, constant pressure might result in skin breakdown or ulcer. Foam Liner would be the best for amputees with soft tissues on the residual limbs to accommodate movement.

Effects of initial stress state on the subsurface stress distribution after ultrasonic impact treatment on thick specimens

Thick welded specimens with different initial stress states were prepared and treated with the ultrasonic impact treatment (UIT). The subsurface stresses before and after UIT were measured by the X-ray diffraction (XRD) method combined with layer removal. The measured results were corrected based on the finite element correction method. The effects of initial high tensile stress and low compressive stress on the in-depth after-UIT stress distributions were investigated. The results show that initial stress has no effects on the stresses induced by the UIT within 1 mm depth and within that depth, UIT can induce almost the same longitudinal and transverse stress curves beneath the surface with a peak compressive stress close to the material yield strength at the depth of near 0.6 mm and 0.8 mm. UIT induces almost the same longitudinal and transverse stresses along with the measured depth under initial low compressive stress state. While under the initial high tensile stress state, the initial stress dominates the final stress distribution over 1 mm depth. Initial high tensile stress (welding residual stress) can reduce the depth of the after-UIT compressive stresses to 62.5% to 75% of that under the initial low-compressive stress state.

Residual stresses and tribomechanical behaviour of TiAlN and TiAlCN monolayer and multilayer coatings by DCMS and HiPIMS

The deposition of ternary nitrides with the incorporation of carbon atoms into its structure has demonstrated to be a promising approach in the pursuit of wear-resistant and self-lubricating coatings. Firstly, both TiAlN and TiAlCN monolayers were deposited using direct current magnetron sputtering (DCMS) and high-power impulse magnetron sputtering (HiPIMS) onto quenched and tempered AISI H11 tool steel to be used as references. Acetylene was used as a carbon precursor, producing DCMS and HiPIMS TiAlCN coatings with 9.0 and 21.7 at.% C, respectively.Subsequently, TiAlN/TiAlCN multilayers of various designs were also developed as follows: 5×[10/500], 5×[50/500] and 5×[100/500] nm. Residual stresses of the coating systems were determined by X-ray radiation utilising an ETA-diffractometer with a Cu-Kα radiation source applying the sin2ψ method. Additionally, residual stresses depth gradients of the substrate before and after the deposition of the coatings were determined in a LEDDI 8-circle diffractometer equipped with a W-X-ray tube and operated in the energy-dispersive mode of diffraction. Great reduction of the compressive residual stresses in the coatings was observed after the introduction of carbon into the TiAlN coating structure, shifting from −1047 ± 149 to −307 ± 211 MPa for the DCMS and from −7035 ± 1361 to +989 ± 187 MPa for the HiPIMS coatings. In the multilayer coatings, compressive residual stresses increase along with the increment of the TiAlN interlayer. Additionally, residual stresses of the substrate in the near-surface are dragged from low compressive stresses (−218 ± 61) to tensile stresses in the range of 1000 to 2000 MPa for all the DCMS/substrate systems, a behaviour only presented in HiPIMS by the TiAlN monolayer. Wear coefficients of all the evaluated HiPIMS systems are notoriously lower than their DCMS counterparts. Compared to TiAlN, TiAlCN HiPIMS presented a lower coefficient of friction but a higher wear coefficient, which in turn was not reduced by the introduction of the multilayer systems. Finally, Scratch test and Rockwell C adhesion tests have shown higher adhesion of DCMS coatings than HiPIMS coatings, and a detriment of the monolayers adhesion by the implementation of TiAlN/TiAlCN multilayer systems. The understanding of the residual stresses, both in the coating and in the substrate, and the way they affect the tribomechanical performance of the system coating/substrate continues to be of great importance, especially for coatings deposited by new technologies such as HiPIMS and self-lubricating coatings.

Elastic and elasto-plastic analysis of Ti6Al4V micro-lattice structures under compressive loads

This article aims to study the modeling and simulation of Ti6Al4V micro-lattice structures under the same compressive loads. Initially, five distinct unit cell topologies (Grid, X, Star, Cross, and Tesseract) were used to design lattice structures. For the modeling of these lattice structures, both three-dimensional wireframe and solid (homogeneous and heterogeneous gradient) meshing were employed. However, the geometric design parameters, such as strut length, strut diameter, and, in particular its configuration (5 × 5 × 5 array), have been assessed as the same for all types of lattice structures. Here, the finite element (FE) modeling approach is used to evaluate the elastic and elasto-plastic behaviors of these structures due to subjected uniaxial compressive loading. The FE results have been validated in previously reported experimental data and have been well comprehended. The static linear and nonlinear FE method formulations are based on the Timoshenko beam theory and Johnson–Cook damaged model, which describe the elasto-plastic behavior. The FE simulations results (linear and nonlinear) were studied and it was shown that Star lattice structure has high stiffness value at low porosity, compared to the other lattice structures. Hence, to further determine the optimum variables (strut diameter –Sd and pore size –PS) for the Star unit cell-based lattice structures, the Taguchi-based optimization technique with L9 orthogonal array was used. In addition, a linear regression model was developed to estimate the maximum initial yield stress for the optimum variables. Finally, the same configuration of Star lattice structures was designed by the heterogeneous solid gradient mesh approach with two swapping conditions, ‘A’ and ‘B.’ These models were employed to perform linear static FE simulations. Therefore, the swapping condition and the type of gradient-based lattice structures, possessing high and low compressive stresses, were identified.

Hollow-cathode chemical vapor deposition of thick, low-stress diamond-like carbon films

A radio-frequency (RF), hollow-cathode plasma source with confining magnetic field is described for the chemical vapor deposition of thick ( > 10 µm), amorphous diamond-like carbon ablator films for inertial confinement fusion applications. Plasma is characterized by optical emission spectroscopy, while properties of the resultant films are measured by a combination of profilometry, Rutherford backscattering spectrometry, elastic recoil detection analysis, X-ray diffraction, Raman spectroscopy, and atomic force microscopy. The dependence of the deposition rate, film density, elemental composition, self-bias and residual stress is reported as a function of RF power. Higher density films were found when using Ar plasma, than N2 or H2 plasma. The coatings produced are x-ray amorphous, exhibit low compressive stress ( ~ 100 MPa), high density ( < 1.7 g/cm3), hydrogen content of ~ 30 at.%, and a low average roughness of 0.75 nm. Applications of these films as tunable-density ablators for inertial confinement fusion experiments are discussed.

A micromechanical tension-compression fatigue hysteresis loops model of fiber-reinforced ceramic-matrix composites

In this paper, a micromechanical tension-compression fatigue hysteresis loops model of fiber-reinforced ceramic-matrix composites (CMCs) is developed. Upon unloading or reloading, the stress-strain of tension-compression fatigue hysteresis loops are divided into three different regions. Multiple micromechanical damage parameters of unloading transition stress, closure stress of the matrix cracking, compressive transition stress, complete compressive stress, and reloading transition stress are adopted to characterize the tension-compression stress-strain hysteresis loops. The characteristics of the tension-compression fatigue hysteresis loops of unidirectional SiC/CAS composite are analyzed for different material properties, damage stage, tensile fatigue peak stress, and compression fatigue valley stress. The experimental tension-tension and tension-compression fatigue stress-strain hysteresis loops of unidirectional SiC/CAS composite are predicted using the developed micromechanical models. Under low fatigue valley compressive stress, the tension-compression fatigue hysteresis loop exhibits no closure of matrix cracking; and under high fatigue valley compressive stress, the tension-compression fatigue hysteresis loops exhibit closure of matrix cracking, and complete compressive in the fiber and the matrix. However, the compressive valley stress has no effect on the values of matrix cracking closure stress, compressive transition stress, and complete compressive stress.

Comparative study of single-layer, bilayer, and trilayer mirrors with enhanced x-ray reflectance in 0.5- to 8-keV energy region

Effective area is one of the most important parameters of x-ray telescopes. It can be increased by enlarging the entrance aperture or maximizing the reflectivity through the proper designing and optimization of the reflecting coating. A method to increase the reflectivity of grazing incidence x-ray mirrors in the 0.5- to 8-keV energy region is analyzed. The idea consists in the use of a trilayer reflecting coating instead of single-layer one (e.g., C/Ni/Pt mirror instead of Pt one). Deposition of low-absorbing medium-Z and low-Z layers onto the top of strongly absorbing high-Z material results in essential increase in the reflectivity while keeping the same width of the reflectivity plateau. In particular, C/Ni/Pt trilayer mirror demonstrates enhancement of the double reflection coefficient by a factor achieving 1.5 to 3.5 compared to that of Pt-coated mirror. The effective area of a telescope is also considerably increased. The experimental results are in a very good agreement with the theoretical predictions. In addition, the C/Ni/Pt trilayer mirror exhibits a reasonable thermal stability and a relatively low compressive stress of about −550 MPa.

Dopants and induced residual stress-controlled thermoelectric properties of ZnO thin films

We investigate the structure, optical properties, and thermoelectric power in terms of residual stresses induced in the undoped ZnOand X-doped ZnO (X = Al, Ga) films. The results show that the different native seed layers self-grown during the initial growth cause compressive stress for ZnO and Ga-doped ZnO films and tensile stress for Al-doped ZnO films. The band-gap of the investigated films follows the Burstein–Moss (BM) effect. It is noted that the ZnO film with the lowest compressive stress has a better PF value below 275 °C. The GZO film is more stable at higher temperatures; therefore, it has a better PF value above 275 °C. The residual stress induced in the investigated films is demonstrated through the formation of a self-grown seed layer under the bombardment of high-energy sputtered Ga, Al, Zn, and O species onto the substrate and during film growth.

Spatial Distribution Evolution of Residual Stress and Microstructure in Laser-Peen-Formed Plates.

Residual stress in structural components is crucial as it affects both service performance and safety. To investigate the evolution of residual stress in a laser-peen-formed panel, this study adopted two plate samples of thickness 3 and 9 mm instead of the conventional Almen strip. The two plates were peened with an identical energy density of 10.99 GW/cm2. The residual stress across the entire section was determined using a slitting method, and near-surface stress was then verified by X-ray diffraction. Furthermore, cross-sectional variation in hardness and microstructure were characterized to understand the residual stress evolution. The experimental results showed that different thicknesses resulted in distinct spatial distributions of residual stress. The 3-mm plate demonstrated a shallow (0.5 mm) and lower compressive stress magnitude (−270 MPa) compared with a deeper (1 mm) and higher compressive stress (−490 MPa) in the 9-mm plate. Further analysis revealed that the deformation compatibility during the forming process inevitably leads to a stress compensation effect on the peened side. The decrease in the depth and magnitude of the compressive residual stress in the thin plate was mainly attributed to low stiffness and large deflection.

Effects of titanium doping on the structure and mechanical properties of diamond-like nanocomposite films

In this paper, we report on comparative studies of mechanical properties of diamond-like nanocomposite (DLN) a-C:H:Si:O films and titanium-doped DLN films, which were focused on (i) nanoindentation and internal stress examination of DLN films of different thickness (up to 10 μm) and (ii) structural transformations and mechanical properties changes with increasing titanium content in Ti-DLN films. The DLN films were found to combine high hardness of 22–24 GPa, high elastic recovery, and low compressive stresses of 100–160 MPa. For Ti-DLN films, the hardness, elastic modulus, and residual stress were found to exhibit similar behavior vs Ti content: an initial decrease at low Ti contents was followed by gradual increase of the hardness, elastic modulus and compressive stresses. The mechanical properties changes were shown to correlate with the structure modifications induced by titanium incorporation into the DLN matrix. Raman spectra of Ti-DLN films revealed three peaks in the low-frequency region from 200 to 700 cm−1, attributed to the TiC phase. An additional evidence of the formation of TiC nanocrystals of several nanometers size was obtained using transmission electron microscopy (TEM) of Ti-DLN films. The findings of Raman spectroscopy along with the TEM data have demonstrated the main factors – formation of TiC nanocrystals and increase of the sp2-carbon content, responsible for the mechanical behavior of Ti-DLN films.