Ti-Al-N-Based Hard Coatings: Thermodynamical Background, CVD Deposition, and Properties. A Review

For several decades, the increasing productivity in many industrial domains has led to a significant and ever-increased interest to protective and hard coatings. In this context, titanium-aluminum nitrides were developed and are now widely used in a large range of applications, due to their high hardness, good thermal stability, and oxidation resistance. This chapter reviews the thermodynamical characteristics of the Ti-Al-N system by reporting the progress made in the description of the Ti-Al-N phase diagram and the main mechanical and chemical properties of Ti1−xAlxN-based coatings. As a metastable phase, the existence of the fcc-Ti1−xAlxN depends on particular process parameters, allowing stabilizing this desirable solid solution. The influence of process parameters, with a particular interest for chemical vapor deposition (CVD) methods, on morphology and crystallographic structure is then described. The structure of Ti1−xAlxN thin films depends also on the aluminum content as well as on the annealing temperature, due to the spinodal nature of the Ti-Al-N system. These changes of crystallographic structure can induce an improvement of the hardness, oxidation resistance, and wear behavior of these coatings. The main mechanical and chemical properties of physical vapor deposition (PVD) and CVD Ti1−xAlxN-based coatings are also described

Air and Vacuum Annealing Effect on the Highly Conducting and Transparent Properties of the Undoped Zinc Oxide Thin Films Prepared by DC Magnetron Sputtering

In this study, we aim to investigate the effect of zinc interstitials (Zni) and oxygen vacancies (VO) on the ZnO electrical conductivity. ZnO films were synthesized via DC magnetron sputtering process using pure Zn target in gases mixture of Ar/O2 = 80/17.5 (sccm). In order to improve the optical and electrical prosperities, the obtained films were subjected to air and vacuum annealing treatment. Several techniques such as field emission scanning electron microscopy (FESEM), Grazing Incidence X-ray Diffraction (GIXRD), Raman spectroscopy, photoluminescence spectroscopy (PL) and UV-visible were used to study the influence of heat treatment on structural and physical properties of ZnO films. Electrical conductivity of ZnO thin films was determined by measuring the sheet resistance and thickness of the films.  XRD results confirm the synthesis of annealed ZnO films of the hexagonal structure with a preferential orientation along the (002) plane. The average crystallite size is altered between 22.6 to 28.4 nm dependent on the plan orientation of the ZnO film. Morphology and crystallinity of the ZnO structure could efficiently control the transmittance, electrical resistivity and optical band gap. As deposited ZnO film showed a lower electrical resistivity of 2.72×10-3 Ωcm due to the Zn-rich conditions. Under vacuum annealing, a combination of low resistivity (1.17×10-2 Ωcm) and better optical transmittance (87 %) are obtained. ZnO films developed in this study with high transmittance and low resistivity and good electro-optical quality supports their use in transparent and conductive electrode applications. The plan presentation was visualized using Vesta, with the lattice parameter set as follows: a = b = 3.249 Å; c = 5.207 Å; α = β = 90°; γ = 120°. Based on the construction and optimization of primitive cells, the supercells were constructed and then optimized. Finally, (002) and (103) planes were cut and the planar supercell structure was constructed. In order to make a plane representation for the solid bulk with 10 Å of thickness

Beneficial effect of Cu on Ti-Nb-Ta-Zr sputtered uniform/adhesive gum films accelerating bacterial inactivation under indoor visible light

This article presents the evidence for the significant effect of copper accelerating the bacterial inactivation on Ti-Nb-Ta-Zr (TNTZ) sputtered films on glass up to a Cu content of 8.3 at.%. These films were deposited by dc magnetron co-sputtering of an alloy target Ti-23Nb-0.7Ta-2Zr (at.%) and a Cu target. The fastest bacterial inactivation of E. coli on this later TNTZ-Cu surface proceeded within similar to 75 min. The films deposited by magnetron sputtering are chemically homogenous. The film roughness evaluated by atomic force spectroscopy (AFM) on the TNTZ-Cu 8.3 at.% Cu sample presented an RMS-value of 20.1 nm being the highest RMS of any Cu-sputtered TNTZ sample. The implication of the RMS value found for this sample leading to the fastest interfacial bacterial inactivation kinetics is also discussed. Values for the Young's modulus and hardness are reported for the TNTZ films in the presence of various Cu-contents. Evaluation of the bacterial inactivation kinetics of E. coli under low intensity actinic hospital light and in the dark was carried out. The stable repetitive bacterial inactivation was consistent with the extremely low Cu-ion release from the samples of 0.4 ppb. Evidence is presented by the bacterial inactivation dependence on the applied light intensity for the intervention of Cu as semiconductor CuO during the bacterial inactivation at the TNTZ-Cu interface. The mechanism of CuO-intervention under light is suggested based on the pH/and potential changes registered during bacterial disinfection. (C) 2017 Elsevier B.V. All rights reserved

Oxidation of magnetron sputtered La-Si thin films for solide oxide fuel cell electronlytes

http://www.sciencedirect.com/science/article/B6TW0-4TN82DN-4/2/d9656db8902a2eb13310e9dca520128

Synthèse et caractérisation de dépôts Al-Cr-(N) et Al-Ti-(N) obtenus par pulvérisation cathodique magnétron en condition réactive

Texte intégral accessible uniquement aux membres de l'Université de LorraineNot availableCe travail porte sur l'élaboration et la caractérisation chimique, structurale, mécanique et électrochimique de revêtements Al-Cr-(N) et Al-Ti-(N) obtenus par pulvérisation cathodique magnétron de cibles composites Al-Cr et Al-Ti dans des plasmas d'argon et d'argon/azote. Les mécanismes de transfert de matière sont d'abord étudiés avec l'aide de l'analyse métallurgique des revêtements, le diagnostic du plasma par spectrométrie d'émission optique et un modèle de pulvérisation adapté à la géométrie des cibles composites. Les revêtements bruts de pulvérisation sont composés de solutions solides microcristallines ou amorphes. L’azote favorise l'amorphisation des revêtements. Les solutions solides amorphes à base d'aluminium qui sont sursaturées en chrome ou en titane et, éventuellement, en azote sont particulièrement étudiées car elles offrent le meilleur compromis entre le renforcement mécanique des revêtements et leurs propriétés électrochimiques. La stabilité thermique de ces revêtements amorphes est aussi discuté

Synthèse et caractérisation de dépôts Al-Cr-(N) et Al-Ti-(N) obtenus par pulvérisation cathodique magnétron en condition réactive

Texte intégral accessible uniquement aux membres de l'Université de LorraineNot availableCe travail porte sur l'élaboration et la caractérisation chimique, structurale, mécanique et électrochimique de revêtements Al-Cr-(N) et Al-Ti-(N) obtenus par pulvérisation cathodique magnétron de cibles composites Al-Cr et Al-Ti dans des plasmas d'argon et d'argon/azote. Les mécanismes de transfert de matière sont d'abord étudiés avec l'aide de l'analyse métallurgique des revêtements, le diagnostic du plasma par spectrométrie d'émission optique et un modèle de pulvérisation adapté à la géométrie des cibles composites. Les revêtements bruts de pulvérisation sont composés de solutions solides microcristallines ou amorphes. L’azote favorise l'amorphisation des revêtements. Les solutions solides amorphes à base d'aluminium qui sont sursaturées en chrome ou en titane et, éventuellement, en azote sont particulièrement étudiées car elles offrent le meilleur compromis entre le renforcement mécanique des revêtements et leurs propriétés électrochimiques. La stabilité thermique de ces revêtements amorphes est aussi discuté

Special Issue “Magnetron Sputtering Deposited Thin Films and Its Applications”

The physical vapour deposition processes, and in particular different variants of sputtering, have reached a maturity making possible industrial applications in numerous fields such as mechanics [...]</jats:p

Special Issue “Magnetron Sputtering Deposited Thin Films and Its Applications”

The physical vapour deposition processes, and in particular different variants of sputtering, have reached a maturity making possible industrial applications in numerous fields such as mechanics [...

Effect of Tantalum Addition on Properties of Cu–Zr–Based Thin Film Metallic Glasses (TFMGs)

Cu–Zr–Ta ternary thin film metallic glasses (TFMGs) were deposited through the direct current (DC) magnetron sputtering of pure metallic targets in a dynamic mode. The effect of tantalum addition on the microstructure, mechanical properties, and thermal behavior of TFMGs were investigated. Nanoindentation measurements showed that an increase in tantalum content from 0 to 47 at % favored hardness and Young’s modulus, which rose from 5.8 to 11.23 Gpa and from 90 to 136 Gpa, respectively. XRD analysis and differential scanning calorimetry (DSC) measurements highlighted an improvement of thermal stability with the tantalum addition from 377 to 582 °C when the tantalum content increased from 0 to 31 at %.</jats:p