Properties Of Titanium Nitride Research Articles

TRIBOLOGICAL PROPERTIES OF SILVER DOPED TITANIUMNITRIDE COATINGS

The properties of titanium nitride (TiN:Ag) coatings applied by physical vapour phase deposition technique(PVD) on Ti13Nb13Zr alloy were subject to evaluation. The study presents the results of surface geometricalstructure, adhesion and tribological tests. The geometric structure of the surface was examined using opticalmicroscopy. A scratch test was used to assess adhesion. The model tribological tests were carried out ina rotary motion under technically dry friction conditions, lubricated with Ringer’s solution. In the case oftechnically dry friction, the analysis of the tribological test results indicated that the TiN:Ag coating wascharacterised by higher resistance to motion and lower wear compared to Ti13Nb13Zr. Friction coefficientsregistered during friction subject to lubrication with Ringer’s solution were compared for both materials;however, the surface wear was significantly lower in titanium alloy. The scratch test pointed towards highadhesion of the TiN:Ag coating. The study results provide insight into Ti13Nb13Zr alloy, titanium nitridecoatings and their potential use for surgical instruments.

TiN nanobridge Josephson junctions and nanoSQUIDs on SiN-buffered Si

We report the fabrication and properties of titanium nitride (TiN) nanobridge Josephson junctions (nJJs) and nanoscale superconducting quantum interference devices (nanoSQUIDs) on SiN-buffered Si substrates. The superior corrosion resistance, large coherence length, suitable superconducting transition temperature and highly selective reactive ion etching (RIE) of TiN compared to e-beam resists and the SiN buffer layer allow for reproducible preparation and result in long-term stability of the TiN nJJs. High-resolution transmission electron microscopy reveals a columnar structure of the TiN film on an amorphous SiN buffer layer. High-resolution scanning electron microscopy reveals the variable thickness shape of the nJJs. A combination of wet etching in 20% potassium hydroxide and RIE is used for bulk nanomachining of nanoSQUID cantilevers. More than 20 oscillations of the V(B) dependence of the nanoSQUIDs with a period of ∼6 mT and hysteresis-free I(V) characteristics (CVCs) of the all-TiN nJJs are observed at 4.2 K. CVCs of the low-I c all-TiN nJJs follow theoretical predictions for dirty superconductors down to ∼10 mK, with the critical current saturated below ∼0.6 K. These results pave the way for superconducting electronics based on nJJs operating non-hysteretically at 4.2 K, as well as for all-TiN qubits operating at sub-100 mK temperatures.

Microstructural effects of the substrate on adhesion strength and mechanical properties of TiN Thin Films

Microstructure of base material plays an important role in adhesion strength and mechanical properties of Titanium Nitride (TiN) coating especially to increase the lifecycle of parts when in practical use. Present study covers the influence of grain size/microstructure of plain carbon steel (tailored via heat treatment) on TiN thin films deposited by physical vapor deposition (PVD) technique. Strong effect of grain size (microstructure) on adhesion strength of TiN thin films on annealed, normalized and quenched substrates have been observed. Mechanical characterization of TiN films e.g. Elastic modulus (E), Hardness (Hv), Stiffness (S) etc. have been studied via nano-indentation technique. TiN thin films failure investigation has been performed with Micro scratch testing under progressive load. Film exfoliation under critical loads has been corroborated via scanning electron microscopy (SEM). The results showed that TiN films deposited on fine microstructure substrate possess excellent mechanical properties and good adhesion strength as compared to coarser microstructure substrate. Insights of this study might be helpful in designing engineered thin films on optimized microstructures.

Peculiarities of the Structural Phase Transformations during Annealing of Doped Titanium-Nitride Coatings

Using the technique of electron-microscope dark-field analysis of the curvature–torsion of a crystal lattice in conjunction with microhardness measurements, a study has been performed of changes in the structural phase state and properties of titanium-nitride based coatings during annealings in vacuum to a temperature of 1573 K. It is shown that in coatings with submicron-size grains fragmented into nanosized subgrains, the magnitudes of local residual elastic stresses associated with elastoplastic curvature of the crystal lattice in regions of excess density of residual dislocations of one sign or with grain-boundary stress concentrators are of defining significance. It is established that in such coatings at high annealing temperatures (≥1373 K) grain coarsening and recovery of the intragrain defect structure develop non-uniformly while retaining high values of the density of the dislocations forming it and maintaining the low-angle boundaries at moderate lattice curvature. For annealings of nanocrystalline coatings, it is established that the intensity of precipitation of second-phase particles based on the doping elements has a defining influence on the hardness, characteristics of the structural state, and level of local stresses of titanium nitride nanocrystals.

Features of the modification of microstructure and properties for copper-doped titanium nitride coatings

Features of a defective microstructure and the mechanical properties of titanium nitride coatings having different copper content are investigated by means of transmission electron microscopy, X-ray structural analysis, microhardness measurement, and scratch tests. It is shown that, under a relatively low deposition temperature and ion-induced surface activation during the growth of a TiN-Cu coating, a highly defective single-phase crystalline state of titanium nitride is formed at a copper concentration of up to 12 at %. The noted state is characterized by a scale hierarchy of the lattice fragmentation from sizes of ∼10–15 to 100 nm, high bending-torsion of the crystal lattice (tens of degrees per micron), and a level of local internal stresses from ∼E/40 to ∼E/120 (E is the modulus of elasticity). The revealed high gradients, including those of a dipole character, for the bending-torsion on characteristic scales up to some tens of nanometers can be described within the framework of a model for the continuous distribution of dislocation-disclination ensembles. The effect of the copper content on an increase in the degree of dispersion of the subgrained structure, a decrease in the local bending-torsion of the crystal lattice within subgrains, the level of local internal stresses, and variation of the hardness and strength in scratch tests is revealed.

Synthesis and protective properties of titanium nitride coatings on willemite

The instability of brightness and light output of a photoluminescent phosphor based on Mn2+-activated willemite (Zn2SiO4:Mn) were examined as influenced by the ultrafine titanium nitride layers synthesized based on a molecular layering technique. Using the technique of radical-recombination luminescence excited in a stream of hydrogen atoms, the spectral characteristics of the initial and of modified phosphors were determined.

Properties of Titanium-Nitride for High-Level Waste Packaging Enhancement

A feasibility study of applying titanium-nitride (TiN) coating onto waste package surfaces was performed as part of efforts to enhance the long-term performance of high-level waste packages. The hypothesis examined in the study is that a successful TiN coating would provide an effective mass-transport barrier thus preventing corrosion. In the present work, single-layer TiN and multiple-layer TiN + Ti, TiN + Ti + TiN, and ZrO2 + TiN were deposited on Type 316L stainless steel substrates. The coated samples were tested for corrosion properties in different types of water using polarization and weight loss tests. Results of corrosion testing are presented and discussed.

Thermal oxidation properties of titanium nitride and titanium–aluminum nitride materials — A perspective for high temperature air-stable solar selective absorber applications

Air-stable high temperature solar selective surfaces have the advantages of simplifying the design, and reducing the cost of solar thermal energy conversion systems. Previous studies on the properties of titanium nitride (TiN) or titanium–aluminum nitride (TiAlN) films suggested that these materials could be a candidate for solar energy applications. In this paper, we report that oxidation occurs at 450 °C, and an oxide layer of about 20–30 nm was formed after only a few minutes of heat treatment with oxygen. The thickness of the oxide layer is comparable to the thickness of the absorbing layer of the solar thermal selective absorbers, which can affect significantly the solar thermal performance. TiN produced at higher nitrogen pressure (2.1 Pa with 40% nitrogen in argon) could absorb oxygen more easily into bulk and was less oxidation resistant during the heat treatment than that produced at 0.4 Pa of 40% nitrogen in argon. The hardness after the oxidation treatment was slightly increased by approximately 10%, consistent with reported oxidation resistant properties of this material for mechanical protection applications. As a result of this study, TiN or TiAlN as an element may not be suitable candidates for use as solar selective absorbers in air-stable high temperature applications.

Synthesis and characterization of low pressure chemically vapor deposited titanium nitride films using TiCl 4 and NH 3

This study investigates the inter-relationships governing the growth kinetics, composition, and properties of titanium nitride (TiN) films synthesized by low pressure chemical vapor deposition (LPCVD) using titanium tetrachloride (TiCl 4) and ammonia (NH 3) as reactants. In the deposition temperature regime of 450 to 600 °C, an Arrhenius dependence was observed from which an activation energy of 42 kJ/mol was calculated. The growth rate dependencies on the partial pressures of NH 3 (50 to 100 mTorr) and TiCl 4 (1 to 12 mTorr) yielded reaction rate orders of 1.37 and −0.42, respectively. RBS spectrometry was used for establishing the Ti/N ratio and the chlorine content of the films as a function of the processing variables. Films with compositions trending towards stoichiometry were produced as the deposition temperature was decreased and the NH 3 partial pressure was increased. The chlorine concentration in the films was observed to decrease from 7.2% ( a/ o) at the deposition temperature of 450 °C down to 0.15% at 850 °C. The film density values increased from 3.53 to 5.02 g/cm 3 as the deposition temperature was increased from 550 to 850 °C. The resistivity of the films was dependent on changes in deposition temperature and flow rate ratios. The lowest resistivity value of 86 μΩ cm was measured for a deposition temperature of 600 °C and an NH 3/TiCl 4 flow ratio of 10/1. The film stress was found to be tensile for all deposits and to decrease with higher deposition temperatures. Nano-indentation measurements yielded values for the hardness and Young's modulus of the films to be around 15 and 250 GPa, respectively. X-ray diffraction measurements revealed in all cases the presence of cubic TiN phase with a preferred (200) orientation. For the investigated aspect ratios of up to 4:1, the deposits were observed to exhibit conformal step coverage over the investigated range of processing conditions.

Effect of processing parameters on the microstructure and mechanical properties of TiN film on stainless steel by HCD ion plating

The effect of operation parameters, bias and nitrogen partial pressure in the microstructure and properties of titanium nitride (TiN) films was investigated. The films were grown using hollow cathode discharge ion plating (HCD-IP) on stainless steel. The structure was studied using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Cross-sectional TEM (XTEM) was used to study the effect of bias, nitrogen partial pressure and pre-deposited Ti-interlayer on the microstructure of TiN films. Plane-view TEM was also employed to measure the grain size of the films. The values of hardness of the films were measured using an ultramicrohardness tester. The results showed that the hardness of the films ranged from 1686–3120 kgf/mm2. The increase in bias enhanced (111) preferred orientation and columnar structure in TiN films. Introducing insufficient nitrogen pressure lowered the crystallinity of the films. The presence of a (0001) preferred orientation in the pre-deposited Ti interlayer enhanced (111) preferred orientation in TiN films. This may be due to the similar atomic packing between (111) in TiN and (0001) in Ti. High hardness of TiN films was found to be associated with a large amount of Ti2N and smaller grain size. The order of the factors, which influence the hardness of the TiN film, is the presence of Ti2N, grain size of TiN, and (111) preferred orientation.

Microstructure and Properties of Titanium Nitride and Titanium Diboride-Based Composites

Microstructure and Properties of Titanium Nitride and Titanium Diboride-Based Composites

Post-treatment of titanium nitride by ion implantation

The properties of titanium nitride and the effects of a post-treatment by ion implantation on coatings made of it are first considered in terms of data available from the scientific literature; 70 references are cited. Data obtained in the present work are then combined with these to offer an explanation of the process mechanisms and structural effects involved. The present work covers monolithic TiN coatings, deposited onto cemented carbide by chemical vapor deposition or steel by physical vapor deposition, and implanted with gas or metal ions at different doses and acceleration energies. The results considered together confirm that large changes in the residual stress and the strain distributions are introduced into the implanted zone (IZ) and extend well beyond forming an implantation affected zone (IAZ) which extends to a depth of several microns The surface of the IZ is amorphized softened by non-metallic implants but not by metallic ions which increase the hardness. The residual stress in the IZ is high, tensile or compressive depending on whether vacancy generation and atom peening effects dominate and is accompanied by concomitant high, irregular, distributions of strain caused by a high dislocation density and/or grain comminution and include high fractions of lattice vacancies. The forward momentum of the ions introduces a dense dislocation network and high residual stress in the IAZ corresponding to the so-called long range effect. The dislocation density increases and the residual stress becomes more compressive with increasing ion momentum.

Mechanical testing and microstructural characterisation of TiN thin films

ABSTRACTMechanical properties of titanium nitride (TiNx) thin films have been investigated using the bulge test and the depth sensing nanoindentation measurements. The bulge test was performed on the square free standing membranes made by means of standard micromachining of silicon wafers, while the nanoindentation was conducted on the films adhered to their supporting substrate. Thin layeres of titanium nitride (t = 300 – 1000 nm) were deposited in a r. f. magnetron sputtering system on the Si(100) wafers containing a layer of low stress LPCVD silicon nitride (SiNy). The bulge test was first conducted on the silicon nitride film to determine its proper residual stress and Young's modulus. Then, the composite membrane made of TiNx together with underlying silicon nitride was bulged and the related load-displacement variation was measured. Finally, using a simple rule of mixture formula the elastic mechanical properties of TiNx coatings were calculated. Both the Young's modulus and residual stress showed increasing values with negative bias voltage and nitrogen to titanium ratio, but the substrate temperature between 50–570°C was found less significant as compared to the other parameters. Nanoindentation data extracted from dynamically loading-unloading of TiN films converged to the bulge test measurements for compact coatings, but diverged from the bulge test data for porous coatings. Scanning electron microscopy observation of the cross sectioned specimens showed that TiN films first grow by formation of the nanocrystallites of size mostly between 10 – 15 nm. These nanocrystallites give rise to the columnar morphology beyond a thickness of 50–100 nm. The columns change their aspect with deposition parameters, but remain nearly perpendicular to the film surface. Relationship between microstructural evolution of columns and mechanical properties of coatings are discussed in terms of deposition parameters.

Structure and Mechanical Properties of Titanium Nitride, Zirconium Nitride, and Chromium Nitride Films by Reactive Magnetron-Sputter Deposition

ABSTRACTTiN, ZrN, and CrN films were grown by reactive magnetron sputtering on WC-Co sintered hard alloy substrates. Hardness and elastic modulus were measured by nano-indentation tester with low load on tip at 200 mgf. Hardness values were shown the higher value the thinner film thickness due to stress in the films.

The effect of target power on the nitrogen partial pressure level and hardness of reactively sputtered titanium nitride coatings

Target power and deposition rate have a significant effect on the properties of titanium nitride (TiN) coatings prepared by high rate reactive sputtering. As the target power is increased from 2.3 to 10.0 kW and the deposition rate from 1000 to 4800 Å min -1, the Vickers microhardness (50 gf) increases from 970 to 3160 kgf mm -2 and the crystallographic orientation goes from a very strong (111) texture to a more random orientation for the TiN coatings. The partial pressures of the argon and nitrogen gases measured through the target show an apparent drop as power is applied to the titanium target. This apparent drop in pressure is actually a density reduction of the gases in front of the target due to gas rarefaction and heating. In order to maintain stoichiometry in the coatings, the partial pressure of the nitrogen reactive gas must be increased as the target power is increased to offset the N 2 density reduction and to compensate for the increase in density of the titanium atoms.

Titanium nitride as a diffusion barrier between nickel silicide and aluminum

The diffusion barrier properties of titanium nitride between nickel silicide and aluminum have been investigated in NiSi Schottky contacts on silicon for annealing temperatures of 400–600°C. No interaction between the metals of the contact structure was detected by backscattering spectrometry, even at 600°C. The electron barrier height of Schottky diodes stays constant at ϕBn = 0.67 ± 0.01 upon thermal annealing in vacuum at 500°C for 2 h . The ideality factor is n = 1.01. After 4 h, ϕ Bn decreases by about 10 mV and n rises to 1.0 6. The diodes degrade after annealing at 550°C or 600°C for 30 min.