Formation Of Titanium Nitride Research Articles

Mechanically tailored surface of titanium based alloy (Ti6Al4V) by laser surface treatment

In this study, laser surface treatment (LST) of Ti6Al4V carried out by melting within a narrow regime of optimum process parameters for the formation of a surface with improved wear and tribo-corrosion resistance is presented. The effect of applied power and shrouding gas on the microstructure, phase, surface hardness, residual stress, dry wear (against tungsten carbide, WC) and tribocorrosion resistance (against ZrO2 in Hank's solution) is established. LST in argon atmosphere leads to the formation of a composite structure consisting of acicular α’ martensite and α. LST in nitrogen atmosphere causes the formation of titanium nitride (TiN and Ti2N) dispersed in α matrix. Due to LST, there is an increase in surface microhardness both under argon (435–630 VHN) and nitrogen atmosphere (839–1327 VHN) when compared to untreated Ti6Al4V (278 VHN). There is a marginal decrease in wear rate (against WC ball) due to laser surface melting (5.17–5.81 × 10−3 mm3/Nm) under argon and a substantial decrease in wear rate when melting was conducted under nitrogen atmosphere (1.91–4.94 × 10−3 mm3/Nm) as compared to Ti6Al4V (5.93 × 10−3 mm3/Nm). The mechanism of wear is established. On the other hand, the tribo-corrosion rate is found to decrease for laser surface melting (3.5–4.8 × 10−3 mm3/Nm) and nitriding (1.3–3.2 × 10−3 mm3/Nm) as compared to Ti6Al4V (5.7 × 10−3 mm3/Nm). Bioactivity in terms of calcium phosphate deposition followed by dipping in Hank's solution was found to increase due to both melting and nitriding, though nitriding offered a marginally higher bioactivity than only melting.

MODIFICATION OF TI-6AL-4V TITANIUM ALLOY SURFACE RELIEF BY COMPRESSION PLASMA FLOWS IMPACT

Investigation of compression plasma flows impact on surface relief of Ti-6Al-4V titanium alloy was carried out in this work. Profilometry, x-ray diffraction, scanning electron microscopy, and sample weight measurements were used as investigation techniques. The findings showed that plasma impact led to the formation of developed surface relief (R<sub>a</sub> parameter was changed in the range of 0.7-2.7 μm) due to the action of hydrodynamic instabilities at the melt-plasma border. Increase in the number of pulses resulted in the growth of R<sub>a</sub> value. Numerical simulation of surface evolution under plasma impact was carried out on the basis of the model of incompressible fluid potential flow. Simulation data correlated with experimental data set. The hydrodynamic flow of the melt during plasma impact led to another process: surface erosion. Increase in both the absorbed energy density and the number of pulses resulted in erosion intensity increase. Formation of titanium nitride on the surface was observed as a result of the interaction of nitrogen (as a plasma generating gas) with the surface heated under plasma impact. Titanium nitride film prevented the development of the surface relief formed by the action of hydrodynamic instabilities.

The effect of cathode arc current on the structures of TiN thin films prepared by cathodic arc deposition

The titanium nitride (TiN) thin films were fabricated by the cathodic arc deposition technique. The effect of titanium cathode arc current on structural, chemical, and morphological properties of thin films was investigated by X-ray diffraction(XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscope (FESEM) and atomic force microscopy (AFM), respectively. The XRD results showed titanium nitride formation with a fcc phase structure for all samples and the preferred orientation changed from (111) to (200) plane with increasing the cathode arc current from 50 to 60 A. The crystallized sizes of the thin films increased as increasing the cathode arc current. In addition, the relationship between the size of the microdroplets on the coating surfaces and the arc current was examined.

Cathodic arc deposition of nanocrystalline titanium nitride thin film on fluorine doped tin oxide coated glass substrate: Crystal structural, microstructural, mechanical, optical and electrical properties

The nanocrystalline titanium nitride (TiN) films were deposited on fluorine doped tin oxide (FTO) coated glass substrates for the first time by cathodic arc deposition. The crystalline phase and orientation, growth morphology, surface roughness, hardness, scratch adhesion, electrical resistivity, optical absorption and bandgap of the TiN films were investigated. The GI-XRD confirmed the formation of cubic TiN and crystallographic orientation growth. The 2150 nm thick TiN film showed (111) orientation due to columnar growth patterns, while the 650 nm TiN film formed with the (200) orientation. The grain size of TiN films was 50–200 nm by FESEM and AFM analyses, and it was formed as elongated nanocrystals of 65–125 nm width and 120–250 nm lengths. The microhardness of the 650, 1000 and 2150 nm TiN thin films was measured to be 836, 943 and 1281 HV0.05 respectively. The scratch adhesion test demonstrated a good adhesive strength up to a critical load of 10 N and beyond the delamination occurred. The electrical resistivity of TiN film found to vary with thickness, the 650 nm TiN film showed a low resistivity of 16 × 10-6 Ω cm, which is comparable with the electrical resistivity of platinum and magnetron sputtered TiN film. The UV-Vis-NIR diffused reflectance spectroscopic studies of the TiN thin film showed a sharp absorption at 448 nm due to plasmon absorption and Tauc plot showed direct band gap of 2.1 eV. The results demonstrated that cathodic arc deposited nanocrystalline TiN thin film deposited on FTO glass substrate can be used as counter electrode for dye sensitized solar cell (DSSC) applications.

Rapid formation of titanium nitride coating by atmospheric-controlled induction-heating fine particle peening and investigation of its wear and corrosion resistance

To create a coating of titanium nitride, atmospheric-controlled induction-heating fine particle peening using fine particles of pure titanium was conducted for low-alloy steel in a nitrogen atmosphere, and the surface characteristics of the treated specimens were investigated. The formation of hard titanium nitride coatings with a thickness of 100–200 μm was achieved by peening at 1373 K for 10 s and subsequent heating at 1373 K for 120 s. Titanium particles adhered to the treated surfaces during peening at the high temperature, which reacted with nitrogen in the atmosphere during the heating after peening. Ball-on-disk wear tests were conducted to examine the wear resistance of the specimens, and it was found that the created coating by AIH-FPP improved the wear resistance of low-alloy steel owing to its high hardness. The improvement was more significant at high testing temperatures because the high testing temperature and frictional heat caused oxygen in the air to react with titanium in the coating during the wear test. Immersion of the specimens into sodium chloride solution was also conducted to investigate the corrosion resistance, which revealed that the coating created improved corrosion resistance of low-alloy steel.

Effect of titanium nitride inclusions on the mechanical properties of direct laser deposited Inconel 718

Additive manufacturing (AM) of metal is attractive for its ability to fabricate complex and tailored structures. However, unusual thermal history during the manufacturing process creates unique microstructures, which leads to non-uniform mechanical behavior. In this paper, we report the room temperature and high temperature mechanical properties of Inconel 718 fabricated by laser-based directed energy deposition. Surprisingly, failure strain at all tested temperatures exhibited noticeable scatter, which is attributed to the formation of titanium nitride (TiN) inclusions. While heat treatment was conducted on AM Inconel 718 to minimize the influence of the inhomogeneous as-built microstructure, it resulted in significant increase in the volume fraction, number density, and maximum particle radius of the TiN inclusions. Consequently, dispersion of mechanical properties became more severe. Experimental investigation (strain mapping, fractography, and X-ray microscopy) supported by finite element analysis implies that premature failure of AM Inconel 718 is mainly due to transgranular cracks of the TiN inclusions that propagates into the matrix.

Structure-dependent optical properties of Au/Ag irradiated TiN thin films

Titanium nitride (TiN) is an attractive alternative for modern and future photonic applications, as its optical properties can be engineered over a wide spectral range. In this study, we have used sequential implantation of gold and silver ions with varying ion fluence, as well as subsequent annealing, in order to modify the optical and plasmonic properties of TiN thin films and correlated this to their structural properties. Our investigations show that the columnar structure of the TiN films is partially destroyed upon implantation, but metallic Au and Ag nanoparticles are formed. The irradiation further induces a reduction of the lattice constant as well as changes the TiN stoichiometry and grain size. From the optical point of view, the implanted films possess less metallicity with increasing Ag fluence and losses several times lower than the as-deposited film, which can be correlated with the deficiency of nitrogen and additional defects. Subsequent annealing partially recovered the destroyed columnar structure, and the films become more metallic where the optical losses are much smaller in comparison to the as-implanted situation, being comparable to those of pure Au and Ag. In this way, by varying the implantation fluence of silver ions properly while keeping the gold fluence constant, we were able to optimize experimental parameters in such a way to ensure the formation of TiN with desirable optical performances.

Duplex surface modification of pure Ti via thermal oxidation and gas nitriding: Preparation and electrochemical studies

The influence of surface modification treatments on the structural, mechanical, and corrosion properties of commercially pure titanium was studied by various tests. The oxynitride layers were formed by applying duplex treatment including thermal oxidation and nitriding at different temperatures. X-ray diffraction showed the formation of titanium oxide and nitride for oxynitrided samples. X-ray photoelectron spectroscopy indicated the formation of TiON in a sample that was nitrided at 900 °C. The microhardness in this sample was 7 times higher than in the untreated sample. Also, the mentioned sample exhibited the highest corrosion resistance in the simulated body fluid at 37 ± 0.5 °C.

Corrosion behavior of TiN layer fabricated by laser irradiation of Ti target in N2/liquid water environment

Laser modification of the titanium (Ti) surface is a practical method to improve Ti mechanical properties such as hardness, corrosion resistance as well as wear resistance. Herein, we presented a simple, cost-effective, and green process to generate the ceramic structure of titanium nitride (TiN) on the Ti metal surface. In this research, for the first time, N2 gas was purged in distilled water chamber and was used as an irradiation environment. The effect of various laser scanning cycles on the structure and corrosion resistance of irradiated samples has been investigated. Different analytical methods were applied to study the characteristics of the irradiated Ti samples. The analysis results confirmed the TiN formation in all laser scanning cycles and a small amount of TiO2 at higher laser scanning cycles. In addition, the Ti surface treatment using laser clearly affects the corrosion behavior in Ringer's solution. The obtained TiN layers show lower corrosion current density and higher polarization resistance than bare Ti. Therefore, by laser irradiation of Ti in N2/liquid water environment, the TiN layer is easily formed, presenting desirable surface properties in the corrosion resistance.

Effect of Heat Treatment on the Microstructure and Hardness of Ni-Based Alloy 718 in a Variable Thickness Geometry Deposited by Powder Fed Directed Energy Deposition

Feature addition to existing parts is a trending application for Directed Energy Deposition (DED) and can be used to add complex geometry features to basic forged geometries with the aim to reduce and simplify the number of processing steps as machining and assembling. However, the mechanical properties of as-deposited Inconel 718 fabricated by Powder-fed Directed Energy Deposition (Powder-fed DED) are far lower than the relevant specifications, making it necessary to apply different heat treatment with the purpose of improving deposited material performance. In addition, the effects of heat treatments in both variable thickness deposited geometry and forge substrate have not been studied. In this study, the effect of heat treatment within the Aerospace Materials Specifications (AMS) for cast and wrought Inconel 718 on the microstructure and hardness of both the Ni-Based Alloy 718 deposited geometry and substrate are analyzed in different parts of the geometry. The microstructure of all samples (as-deposited and heat-treated) is analyzed by Scanning Electron Microscope (SEM) and Energy Dispersive Spectrometer (EDS), confirming the formation of aluminum oxides and titanium nitrides and carbonitrides in the deposited structure.

Investigation on the fretting wear behavior of titanium alloy under different atmospheres by an in situ XPS spectrometry

In this paper, a systematic experimental investigation concerning the fretting wear behavior of Ti6Al4V titanium alloy under the nitrogen, argon and air atmospheres is reported. An in-situ XPS analysis test combined with a self-designed high precision fretting wear tester was employed to probe the tribo-chemical state. The fretting wear volume and fretting wear mechanism under different atmospheres were analyzed and the correlations of tribo-chemical state with the fretting wear behavior were discussed. Results suggest that the working atmosphere has a significant effect in determining the formation of tribo-chemical products on the worn scars and then the fretting wear resistance depending on fretting run regimes. In the PSR, the working atmosphere has little effect on the tribo-chemical reaction and then the fretting wear. While in MFR, the worn scars under the nitrogen atmosphere show the highest fretting wear volume but the lowest fretting wear volume under the argon atmosphere. In SR, Ti6Al4V titanium alloy under the nitrogen and argon atmosphere presents a much high fretting wear volume, which may be due to the formation of titanium nitrides and Ti2O3 and TiO, respectively. In contrast, under the air atmosphere, Ti6Al4V titanium alloy presents the lowest fretting wear volume, which could be attributed to the protective effect of a compacted TiO2 oxidized film.

Structures and Mechanical Properties of Pure Titanium by Different Boriding and Nitriding Conditions

Structure and mechanical properties of pure titanium by combined processing of boriding and nitriding with different processing temperatures in the heating furnace have been investigated. The effect of combined processing temperature for 2 h on the structure and mechanical properties of the treated specimens. As a result of the examination, combined processing at all designed temperatures resulted in the formation of titanium nitride, where the content of the nitride depended greatly on the processing temperature. When the processing temperature is 1300°C, the cross-sectional hardness of the hardened layer reaches the maximum. At the same temperature, the bonding strength also reaches the maximum, which is related to the performance of the hardened layer. Based on these results, when the processing temperature is 1300°C, the combined processing of pure titanium can improve the overall performance.

Isothermal short‐term oxidation behavior of MAR‐M246 nickel‐based superalloy at 800°C and 1000°C

AbstractSuperalloys are widely employed at high temperatures for structural applications. Hence, knowledge about the oxidation of these materials is essential. However, the literature is scanty when it comes to some families of superalloys. The purpose of this study was therefore to analyze the MAR‐M246 polycrystalline alloy in isothermal short‐term tests at 800°C and 1000°C for up to 240 h. Thermodynamic simulations were performed to evaluate the material's phase stability as a function of temperature and to assess the expected phases in response to oxygen pressure. The oxidized samples were characterized by SEM‐EDS and DRX, which revealed a tendency for scaling of oxidized material, particularly at temperatures of 1000°C. Nevertheless, protective layers of Cr2O3 and Al2O3 oxides were formed, which enabled the formation of fairly thin oxide layers, in addition to NiO and complex oxides. The region of the metallic substrate close to the oxide layer underwent aluminum depletion, causing the gamma‐prime phase to disappear, as well as formation of aluminum oxides and titanium nitrides. Last, a good correlation was found between the thermodynamic simulations and the oxides that were formed.

Исследование формирования многослойного функционального композиционного материала с градиентной структурой “нитрид титана – титан – основа”

Composite materials based on aluminum alloy D16 and titanium alloy Ti – 10 Nb – 3 Mo with surface layers of titanium, titanium nitride and a multilayer composition consisting of alternating layers of titanium and titanium nitride for biomedical and tribological purposes by high-vacuum magnetron sputtering at direct current in inert and reactive media were obtained. The structure and phase composition were studied using SEM, AES, X-ray diffractometry and probe microscopy. The rate of formation of a surface layer of pure titanium on a substrate made of alloy D16 was 185 nm/min, and the rate of synthesis of a surface layer of titanium in a reactive medium was significantly slowed down and was no more than 70 nm/min due to nitrogen poisoning of the target. The transition layer formed as a result of the synthesis of a titanium layer on an aluminum alloy substrate had a thickness of about 600 nm, which is significantly greater than the thickness of the transition layer when titanium is obtained on a titanium alloy substrate. During the formation of titanium nitride on a titanium sublayer, a greater concentration of nitrogen was observed than during the formation of nitride on a substrate with the same deposition parameters. The intensity of the TiN phase reflexes in the X-ray diffractometry diagrams were weakly expressed in all variants of the applied ratios of working gases Ar/N2 during spraying. The speed of the titanium sublayer makes it possible to form a greater thickness of the titanium nitride layer than without the sublayer, as well as a more nitrogen–saturated surface layer - up to 38% by weight.

Effects of parameters on titanium nitride formation at atomic level

The effects of parameters on nanoscale titanium nitride during the formation process in ferrite were studied via the molecular dynamics (MD) simulation. The formation of titanium nitride was executed by employing a dislocation-motivated formation model in which the atomic diffusion has a significant contribution. The roles of N/Ti atom ratio, temperature and matrix defect were identified and the according nitride formation property was analyzed.

TiN formation on Ti target by laser ablation method under different N2 gas pressure and laser scanning cycles: A wettability study

Titanium (Ti) and its alloys have vast applications in industry. However, surface modification technology should be performed to maintain Ti properties for its use in a variety of applications. Titanium nitride (TiN) is often used as a coating to improve surface properties due to its special characteristics. In this research, the laser ablation method is applied on Ti target in N2 atmosphere to make TiN structure using a fiber laser. The different N2 gas pressures and the number of laser scanning cycle effect was investigated on the formation of TiN structure. Different techniques were utilized to scrutinize samples. It was concluded that increasing the laser scanning cycle has a greater effect on the amount and quality of TiN structure compared to the change of N2 gas pressure. The aging effect on ablated surface wettability of samples was assessed by water contact angle (WCA) measurement. The samples illustrated superhydrophilic behavior immediately after laser processing and became hydrophobic over time. Due to the fact that the surface morphology didn't change with the aging effect, the wettability changing is due to the surface chemical composition by the oxidation process and adsorption of the airborne organic compounds of TiN surface by the effect of the long-term storage of ablated sample in the air that was studied by the X-ray photoelectron spectroscopy (XPS).

Characterization of the surface layer modified in ti6-al7-nb alloys by plasma nitriding using cathodic cage

Using titanium as the base metal of biomaterials has gained attention due to its excellent mechanical properties, biocompatibility, and resistance to corrosion and wear. In this research, Ti6-Al7-Nb (wt%) alloy has been superficially modified by cationic cathode plasma nitration (CCN) in order to improve the pre-existing biocompatible characteristics in the alloy. Four treatment conditions and a standard sample, for comparative purposes, were chosen. Nitriding was implemented using a cathodic cage technique at a different time and temperature conditions, and at constant pressure. Samples 1 and 2 were treated at a temperature of 300°C for 1h and 2h, while samples 3 and 4 were treated at 400°C for 1h and 2h, respectively. The characterization techniques used were: SEM, EDS, XRD, microhardness, and roughness. The results regarding SEM and EDS techniques revealed the formation of a TiO2 film for three samples. The XRD analysis showed the existence of a peak related to the formation of titanium nitride (TiN), in various proportions, for all analyzed samples. The formation of the film also confirms a hardness increase for conditions 1, 2 and 3. The analysis of the roughness demonstrated results for rounded peaks for samples 1, 2 and 4, where sample 4 revealed the lowest roughness value. In light of the results, it was possible to verify that the nitrided samples had their properties, partially or integrally, improved in relation to the standard one.

Preparation of Metal Nitride Particles Using Arc Discharge in Liquid Nitrogen.

A simple process to synthesize metal nitride particles was proposed using submerged arc discharge plasma in liquid nitrogen. Gibbs standard free energy was considered for the selection of the nitride-forming materials. In this study, titanium (Ti) and aluminum (Al) electrodes were used as raw materials for nitride particle preparation. Liquid nitrogen acted as a dielectric medium as well as a nitridation source in this process. A copper electrode was also used as a non-reactive material for comparison with the reactive Ti and Al electrodes. As the operating conditions of the experiments, the arc discharge current was varied from 5 A (low-power mode) to 30 A (high-power mode). The formation of titanium nitride (TiN) and aluminum nitride (AlN) was confirmed in the particles prepared in all experimental conditions by X-ray powder diffraction (XRD). The observation using a field emission scanning electron microscope (FE-SEM) and a field emission transmission electron microscope (FE-TEM) indicated that the synthesized TiN particles showed a cubic morphology, whereas AlN particles containing unreacted Al showed a spherical morphology. The experiments using different metal electrode configurations showed that the anode generated most of the particles in this process. Based on the obtained results, a particle formation mechanism was proposed.

Formation of Titanium Nitride, Titanium Carbide, and Silicon Carbide Surfaces by High Power Femtosecond Laser Treatment.

Invited for this month's cover is the group of Prof. Eike G. Hübner at Fraunhofer Heinrich Hertz Institute HHI, Goslar and Clausthal University of Technology, Clausthal-Zellerfeld, Germany. The cover picture shows a titanium plate, on which the crystal structure (golden circle=Ti, blue circle=O/N/C) of isomorphous TiO, TiN or TiC, respectively, has been engraved by a high-power high pulse repetition rate femtosecond laser process. The process allows for a fast and spatially resolved surface transformation of titanium to golden TiN, blue TiO/TiO2 or black TiC in an atmosphere of nitrogen, air or ethene/argon. The background represents a typical surface microstructure of these interstitial compounds obtained during this transformation. Read the full text of the article at 10.1002/cplu.202100118.

Formation of Titanium Nitride, Titanium Carbide, and Silicon Carbide Surfaces by High Power Femtosecond Laser Treatment.

Coatings based on titanium nitrides, titanium carbides and silicon carbides can optimize the surface properties of titanium or silicon for various applications ranging from biocompatibility to chemical stability and durability. Here, we investigated a high power (100 W) high pulse repetition rate femtosecond laser process (λ=1030 nm, τ=750 fs, f=1 MHz) for the treatment of titanium and silicon in atmospheres of argon, nitrogen, methane, ethene and acetylene. In a nitrogen atmosphere, a homogeneous coating of TiON is formed on titanium. In an ethene/argon atmosphere coatings of TiOC and SiC are formed on Ti and Si, respectively. The process allows a fast surface transformation with a process rate of 0.33 cm2 s-1 and a high spatial resolution below 0.5 mm with a minimal heat affected zone at the same time. In contrast to low repetition rate femtosecond laser processed samples, the surfaces are more robust against mechanical impact. At the same time, the surfaces reveal a distinct microstructure in comparison to coatings obtained by vapor deposition techniques.