Papers by Keyword: Titanium Nitride

Abstract: Hard nitride coatings has an important role for enhancing the wear resistance of metallic materials, thus increasing the life time of the products in industries. In this paper reviews the different methods of coating techniques, methods of PVD, mechanical properties of TiN coatings and wear resistance of titanium nitride-based coatings by physical vapor deposition (PVD) techniques. Thus the various approaches for enhancing the corrosion and wear resistance are categorized and summarized. The advantages, disadvantages and applications of Nitride based coatings are discussed.

Abstract: In this work, the adhesion and corrosion resistance of TiN coating by magnetron sputtering on stainless steel substrates under different bias voltages conditions (-50 V and-100 V) was investigated. AFM was used for surface roughness and grain size analysis, XRD for phase identification, Rockwell C for adhesion and nanoindentation for hardness and elastic modulus. According to AFM the coating deposited at-100V bias had decreased surface roughness, the value decreased from 2.7 nm (for-50V sample) to 1.8 nm, this was due to an etching like process which occurs when ions with higher energies start hitting the surface. The coated samples came under HF1 adhesion parameter which is the highest class of adhesion in the model on the basis of Rockwell C adhesion test. nanoindentation hardness and elastic modulus results of-50 V and-100V were found to be 224 GPa and 182 GPa, respectively and the value of hardness, 16 GPa and 22 GPa, respectively. The corrosion behavior of TiN coatings were studied in 3.5wt. % NaCl solutions using Tafel Extrapolation, Cyclic Polarization and Open Circuit Potential. It was noted on the basis of these corrosion tests that, as bias voltage is increased, it leads to the formation of more densely packed, fine grained columnar structures with less pores, which decreases the chances of corrosion. .

Abstract: Aluminum is a lightweight material that is commonly used in engine components. However, aluminum's low hardness and wear resistance, requires special treatment before being used as a component. Increasing the hardness and wear resistance of aluminum can be done by coating Titanium Nitride (TiN) with the sputtering method. In this study, the effect of sputtering time on Al-TiN coating on hardness and wear resistance was obtained. The deposition of titanium nitride thin films on aluminum using a gas ratio of Ar: N ((70:30%) with varied treatment times of 30, 60, 90, and 120 minutes. Hardness and wear resistance were observed using Vickers hardness tester and Ogoshi High-Speed Universal. Whereas the morphology of the wear surface was observed by SEM. The result shows that the treatment time of 60 minutes obtained the highest hardness and minimum specific wear rate.

Abstract: The main objective of the present work was to characterize the phases that are present after solution annealing in the microstructure of the titanium stabilized austenitic stainless steel W.-Nr. 1.4970, developed as a candidate material for fast breeder reactor fuel cladding. The crystalline structure, chemical composition, quantity, size, morphology, and distribution of the phases present in the microstructure after solution annealing heat treatments were studied in detail with the help of several complementary techniques. Chemical dissolution of the matrix has been performed using the Berzelius solution and the extracted residue has been analyzed by X-ray diffraction in a high precision camera. Three phases have been observed and identified after solution annealing heat treatments performed in the 1090 to 1300 °C temperature range, namely: (Ti,Mo)C; Ti (N,C) and Ti₄C₂S₂. The Ti-nitride and the Ti-carbosulfide did not dissolve in the steel matrix up to 1300 °C, on the other hand, the solubility of the (Ti,Mo)C raised strongly with temperature. A solution annealing heat treatment is recommended for the W. Nr. 1.4970 stainless steel.

Abstract: Ti-based coating has been used for biomaterials to improve biocompatibility, mechanical and corrosion properties. Each coating shows unique performance depending on a variety of factors such as coating microstructure and properties as well as in-service conditions. In this study, the microstructure, surface topography, hardness, adhesion and corrosion properties of Ti and TiN films on stainless steel 316L coated by cathodic arc physical vapor deposition process (PVD) were studied. The results showed that the surface roughness of 316L increased after being coated with Ti and TiN film as evidenced by the numerous particles and voids observed on the surface of both films. The hardness of 316L coated with Ti and TiN was increased by approximately 50% and 85%, respectively. Ti and TiN coated samples showed good adhesion strength with the first critical load (LC1) of approximately 10N and 15N, respectively. However, the types of film failure for Ti and TiN were found to be different. Partial delamination with a high degree of plastic deformation was observed for Ti coating, whereas surface cracks were found for TiN coating. This finding is likely attributable to the difference in flow resistance and the amount of particles and voids observed. All samples showed a stable passive region during 7 days of immersion in Ringer’s solution. Ti film showed better corrosion resistance than TiN, which may have been caused by the effect of more voids on TiN surfaces formed by PVD coating.

Abstract: In the present study austempered ductile irons (ADI) with lower bainitic structure are investigated. Nanosized particles (50nm) of titanium carbonitride + titanium nitride TiCN+TiN and titanium nitride TiN are added to the casting volume. The samples microstructure is studied by optical metallography and X-Ray analysis. The influence of the nanosized additives on the kinetics of the bainitic transformation and on the morphology of the bainitic structure is investigated. The abrasive wear testing, hardness measurements and impact strength are carried out. It is established that the presence of nanoadditives in the bainitic cast irons leads to the changes in their microstructure which increases their mechanical characteristics and abrasive wear resistance. The studied nanocomposite materials expand the potential for new ADI applications in the industry.

Abstract: This work presents the experimental results of the study of the effect of heat treatment on the structural-phase state of TiN coatings on the surface of 67KH5B alloy. It is determined that thermal annealing leads to structural phase transformations at the interface between the coating and the substrate. It was established that after annealing at Т=800 ^°С, due to the redistribution of the coating elements and the substrate, a modified coating is formed consisting of the TiN, Ti2N and NiTi phases.

Abstract: Abstract. In the present work several films of Ti, TiN, and TiCrN have been coated on AISI 316L stainless steel substrates using magnetron sputtering techniques, in order to improve their surface properties. The morphology and structure of the coatings were analysed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The electrochemical performances skills in an SBF solution and the adhesion of these deposits were studied to understand these behaviors. From the results it was shown the TiCrN deposition presents the lowest corrosion resistance in the SBF solution, while TiN deposit is the most resistant to corrosion resistance in the same solutions, but its critical load (Lc3-TiN), is relatively low and has a risk of delamination which can limit its use. On the other hand, the Ti deposit exhibits a high resistance to corrosion and a high passivation (i_corr (Ti) = 0.57 µA.cm^-2 and Rp (Ti) = 67.98 KW.cm²). The critical load (Lc3-Ti = 43.38 N), the crack propagation resistance (CPRs-Ti = 81.64 N) and the scratch hardness (HSL-Ti = 125.75´10¹² Pa) also testify to its high adhesion to the AISI 316L substrate. Thus the Ti deposit has proved to be the most favorable protective coating for AISI 316L stainless steel in SBF solution.

Abstract: The DC magnetron sputtering is often used for fabricating thin hard coatings for a wide range of industrial applications. The technique allows using DC power for deposition low or non-conductive films from metal target without using expensive RF power for insulation target. However, the performance of DC reactive sputtering is affected significantly by a phenomenon namely target poisoning. When the target poisoning occurs, coating is formed not only on substrate surface but also on target surface, which results in the reduction of deposition rate and coating properties. This paper presents a study on poisoning of Ti target during TiN coating deposition in the Ar + N₂ atmosphere. Results showed that the target poisoning state is impressed dramatically by partial pressure and flow rate of nitrogen gas. In poisoning mode, the deposition rate was reduced significantly compared to that in the metal mode. In addition, the formed TiN coating exhibited a non-stoichiometric and low adhesion to the substrate.

Abstract: Electric current assisted sintering of β-Si₅AlON₇-TiN ceramic composites from raw materials prepared by combustion synthesis was investigated. A high level of relative density (92% and higher) was achieved by using of two types of electric current assisted sintering technique: high voltage electric discharge consolidation, as well as spark plasma sintering. While only spark plasma sintering, it may be considered as promising technique for obtaining ceramic composites and items with high level of strength properties.