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Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Corrosion, Action des agents de corrosion, Corrosion environments, Alliage base nickel, Nickel base alloys, Corrosion, Corrosión, Korrosion, Dépôt chimique, Chemical deposition, Depósito químico, Stromloses Beschichten, Irradiation, Irradiación, Bestrahlung, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Résistance corrosion, Corrosion resistance, Resistencia corrosión, Korrosionsbestaendigkeit, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Coatings, Electroless plating, Magnesium alloy, and Ultrasonic irradiation

Ultrasonic irradiation (UI) is applied to assist the electroless plating (EP) Ni―P coating on a magnesium alloy substrate. The results show that under UI, the Ni―P coating becomes smooth, compact, has refined grains and is free of cracks and pores, leading to significant improvement in the coating corrosion resistance. The crystallinity of the coating is also improved by UI, transforming from amorphous state to mixture of amorphous and nanocrystalline one.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Propriétés mécaniques. Rhéologie. Mécanique de la rupture. Tribologie, Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology, Frottement. Usure, Contact of materials. Friction. Wear, Propriété mécanique, Mechanical properties, Propiedad mecánica, Adhérence, Adhesion, Adherencia, Adhaesion, Application, Aplicación, Anwendung, Dépôt projection, Spray coating, Depósito proyección, Spritzbeschichten, Erosion, Erosión, Force adhérence, Adhesive strength, Fuerza adherencia, Haftfestigkeit, Plasma, Projection plasma, Plasma spraying, Proyección plasma, Plasmaspritzen, Projection à chaud, Hot spraying, Proyección en caliente, Spritzen, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Résistance mécanique, Strength, Resistencia mecánica, Festigkeit, Résistance usure, Wear resistance, Resistencia al desgaste, Verschleissfestigkeit, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Tribologie, Tribology, Tribología, Turbine gaz, Gas turbine, Turbina gas, Gasturbine, Usure, Wear, Desgaste, Verschleiss, MCrAlY, abradable coating, adhesive strength, atmospheric plasma spray (APS), erosion resistance, gas turbines, and rubbing wear

The processing conditions, microstructural and tribological characterizations of plasma-sprayed CoNiCrAlY-BN high temperature abradable coatings are reported in this manuscript. Plasma spray torch parameters were varied to produce a set of abradable coatings exhibiting a broad range of porosity levels (34-62%) and superficial Rockwell hardness values (0-78 HR15Y). Abradability tests have been performed using an abradable-seal test rig, capable of simulating operational wear at different rotor speeds and seal incursion rates (SIRs). These tests allowed determining the rubbing forces and quantifying the blade and seal wear characteristics for slow and fast SIRs. Erosion wear performance and ASTM C633 coating adhesion strength test results are also reported. For optimal abradability performance, it is shown that coating hardness needs to be lower than 70 and 50 HR15Y for slow and fast blade incursion rate conditions, respectively. It is shown that the erosion wear performance, as well as, the coating cohesive strength is a function of the coating hardness. The current results allow defining the coating specifications in terms of hardness and porosity for targeted applications.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Métallurgie des poudres. Matériaux composites, Powder metallurgy. Composite materials, Poudres métalliques, Metal powders, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Propriétés mécaniques. Rhéologie. Mécanique de la rupture. Tribologie, Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology, Alliage mécanique, Mechanical alloying, Aleación mecánico, Mechanisches Legieren, Dépôt projection, Spray coating, Depósito proyección, Spritzbeschichten, Matériau composite, Composite material, Material compuesto, Verbundwerkstoff, Métallurgie poudre, Powder metallurgy, Metalurgia polvo, Pulvermetallurgie, Projection HVOF, HVOF spraying, Proyeccion HVOF, Projection à chaud, Hot spraying, Proyección en caliente, Spritzen, Propriété mécanique, Mechanical properties, Propiedad mecánica, Revêtement composite, Composite coating, Revestimiento compuesto, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, HVOF, cold spray, mechanical alloying, mechanical properties, metal matrix composite, and nickel alloys

The purpose of this study is to manufacture metal matrix composite coatings by thermal spraying. In order to improve coating's mechanical properties, it is necessary to increase homogeneity. To meet this objective, the chosen approach was to optimize the powder morphology by mechanical alloying. Indeed, the mechanical alloying method (ball milling) was implemented to synthesize NiCr-Cr3C2 and NiCrBSi-WC composite powders by using cold spraying and high-velocity oxygen fuel process, respectively. After optimizing the process parameters on powder grain size, the composite coatings were compared with standard coatings manufactured from mixed powders. SEM observations, hardness measurements, and XRD analyses were the first technologies implemented to characterize the metal matrix composite coatings. Different characteristics were then observed. When mechanical alloying process is employed to synthesize composite powders strengthened by particle dispersion, the powders tend to fracture into small segments, especially when high content of hard particles is added. Powder microstructures were then refined, which induced thinner coating morphologies and reduced porosity rate. Once an improved microstructure is obtained, manufacturing of coating using milled powders was found suitable in comparison with coatings manufactured only with mixed powders.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Dépôt de matériaux non métalliques, Nonmetallic coatings, Barrière thermique, Thermal barrier, Barrera térmica, Plasma, Projection plasma, Plasma spraying, Proyección plasma, Plasmaspritzen, Projection à chaud, Hot spraying, Proyección en caliente, Spritzen, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Revêtement non métallique, Non metal coating, Revestimiento no metálico, Nichtmetallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Vitesse, Velocity, Velocidad, MCrAlY, Triplex torch, atmospheric plasma spraying, bondcoat, and thermal barrier coating

MCrAlY bondcoats (M = Co, Ni) are used to protect metallic substrates from oxidation and to improve adhesion of ceramic thermal barrier coatings for high temperature applications, such as in land-based and aviation turbines. Since MCrAlYs are prone to take up oxygen during thermal spraying, bondcoats often are manufactured under inert gas conditions at low pressure. Plasma spraying at atmospheric conditions is a cost-effective alternative if it would be possible to limit the oxygen uptake as well as to obtain sufficiently dense microstructures. In the present work, high-velocity spray parameters were developed for the TriplexPro 210 three-cathode plasma torch using MCrAlY powders of different particle size fractions to achieve these objectives. The aims are conflictive since the former requires cold conditions, whereas the latter is obtained by more elevated particle temperatures. High particle velocities can solve this divergence as they imply shorter time for oxidation during flight and contribute to coating densification by kinetic rather than thermal energy. Further aims of the experimental work were high deposition efficiencies as well as sufficient surface roughness. The oxidation behavior of the sprayed coatings was characterized by thermal gravimetric analyses and isothermal heat treatments.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Métallurgie des poudres. Matériaux composites, Powder metallurgy. Composite materials, Métaux renforcés par dispersion, Dispersion hardening metals, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Agglomération minerai, Ore sintering, Aglomeración mineral, Erzsintern, Alliage base nickel, Nickel base alloys, Broyage, Grinding(comminution), Molienda, Mahlen, Dureté, Hardness, Dureza, Haerte, Dépôt chimique, Chemical deposition, Depósito químico, Stromloses Beschichten, Dépôt projection, Spray coating, Depósito proyección, Spritzbeschichten, Essai dureté, Hardness test, Ensayo dureza, Haerteversuch, In situ, Lubrifiant, Lubricant, Lubricante, Schmiermittel, Matériau composite, Composite material, Material compuesto, Verbundwerkstoff, Métal renforcé dispersion, Dispersion strengthened metal, Metal reforzado dispersión, Dispersionsgehaertetes Metall, Métallurgie poudre, Powder metallurgy, Metalurgia polvo, Pulvermetallurgie, Nickel, Niquel, Nickelage, Nickel plating, Niquelado, Vernickeln, Nitrure de bore, Boron nitride, Boro nitruro, Bornitrid, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, agglomeration, aluminum substrate, ball milling, cold spray, electroless nickel plating, hardness testing, hexagonal-boron nitride, nano-engineered coating materials, and nickel

Nano-engineered self-lubricating particles comprised of hexagonal-boron-nitride powder (hBN) encapsulated in nickel have been developed for cold spray coating of aluminum components. The nickel encapsulant consists of several nano-sized layers, which are deposited on the hBN particles by electroless plating. In the cold spray deposition, the nickel becomes the matrix in which hBN acts as the lubricant. The coating demonstrated a very promising performance by reducing the coefficient of friction by almost 50% and increasing the wear resistance more than tenfold. The coatings also exhibited higher bond strength, which was directly related to the hardenability of the particles. During the encapsulation process, the hBN particles agglomerate and form large clusters. De-agglomeration has been studied through low- and high-energy ball milling to create more uniform and consistent particle sizes and to improve the cold spray deposition efficiency. The unmilled and milled particles were characterized with Scanning Electron Microscopy, Energy-Dispersive X-Ray Spectroscopy, BET, and hardness tests. It was found that in low-energy ball milling, the clusters were compacted to a noticeable extent. However, the high-energy ball milling resulted in breakup of agglomerations and destroyed the nickel encapsulant.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Dépôt projection, Spray coating, Depósito proyección, Spritzbeschichten, Efficacité, Efficiency, Eficacia, Wirkungsgrad, Modèle mathématique, Mathematical model, Modelo matemático, Mathematisches Modell, Modélisation, Modeling, Modelización, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Turbine, Turbina, MCrAlY, analytical model, bond coats, cold spray, deposition efficiency, process modeling, and turbines

The cost structure of the cold spray (CS) process is analyzed using a generic cost model applicable to all present types of CS systems (high pressure, low pressure, KM™, kinetic spraying, etc.) and kinds of application (coating, restoration, additive manufacturing, near-net forming). The cost model has originally been developed at SIEMENS and is easy to use, while being sufficiently accurate to support decisions. The dependence of the process costs on the gas stagnation properties is discussed. It is shown (i) that high pressure is generally favorable, (ii) that He-N2 blends possess economic potential, and (iii) that He recovery saves costs in high volume production, even when He-N2 blends are used. The cost model allows for the determination of the cost-optimal He concentration of the propellant gas for a given application. CS is, among others, suited to spray bond coatings on gas turbine blades and offers cost-saving potential, as shown in a case study.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Corrosion, Action des agents de corrosion, Corrosion environments, Protection contre la corrosion, Corrosion prevention, Corrosion, Corrosión, Korrosion, Dépôt conversion, Conversion coating, Depósito conversión, Konversionsbeschichten, Phosphate, Phosphates, Fosfato, Phosphat, Protection corrosion, Corrosion protection, Protección corrosión, Korrosionsschutz, Préparation surface, Surface preparation, Preparación superficie, Oberflaechenvorbereitung, Prétraitement, Pretreatment, Pretratamiento, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Conversion coatings, Magnesium alloys, Metal phosphates, and Surface pretreatment

This work describes a group of metal phosphate films, including calcium, manganese and strontium phosphate conversion coatings, for corrosion protection of magnesium alloys. These films have been developed by a process that is simple for implementation, chemically stable and non-toxic. The preparation and characterisation of these coatings, along with evaluation of their corrosion performance in 0·1M NaCl, are systematically described. Phase diagram of calcium phosphate was produced to elucidate the coating formation mechanism, which depends upon the chemistry of coating solution, in particular pH and ion concentration. A discussion of the advantages and disadvantages of the coatings is presented, along with perspectives for industrial applications.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Corrosion, Action des agents de corrosion, Corrosion environments, Alliage base nickel, Nickel base alloys, Chlore, Chlorine, Cloro, Chlor, Corrosion à chaud, Hot corrosion, Corrosión en caliente, Heisskorrosion, Dépôt projection, Spray coating, Depósito proyección, Spritzbeschichten, Projection à chaud, Hot spraying, Proyección en caliente, Spritzen, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Superalliage, Superalloy, Superaléación, Superlegierung, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Coating, and Corrosion

In this work, the NiCrAlY coating was deposited by cold spray deposition technique on Fe based Superfer 800H superalloy. The cold sprayed coating was found to be dense and hard and adhered strongly to the substrate superalloy. In the present investigation, the cyclic hot corrosion behaviour of the coated and bare specimens under the Na2SO4-10%NaCl environment at 900°C is described. It is found that unlike bare superalloy, uniform, dense and adhered scale layer formed on top of the coated specimen. The various characterisation techniques X-ray diffraction, SEM/EDAX and elemental X-ray mapping were used to analyse the corrosion products. It was found that the coating deposited by this coating technique successfully provided protection to the substrate against the hot corrosion degradation by reducing the weight gain of the superalloy.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Dépôt de matériaux non métalliques, Nonmetallic coatings, Corrosion, Action des agents de corrosion, Corrosion environments, Adhérence, Adhesion, Adherencia, Adhaesion, Affinement grain, Grain refinement, Afino grano, Kornfeinen, Alumine, Alumina, Alúmina, Tonerde, Aluminure, Aluminides, Aluminuro, Composé intermétallique, Intermetallic compound, Compuesto intermetálico, Intermetallische Verbindung, Corrosion, Corrosión, Korrosion, Couche oxyde, Oxide layer, Capa óxido, Oxidschicht, Grosseur grain, Grain size, Grosor grano, Korngroesse, Microscopie électronique balayage, Scanning electron microscopy, Microscopía electrónica barrido, Rasterelektronenmikroskopie, Microscopie électronique transmission, Transmission electron microscopy, Microscopía electrónica transmisión, Transmissionselektronenmikroskopie, Microstructure, Microestructura, Mikrogefuege, Oxydation, Oxidation, Oxidación, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Revêtement non métallique, Non metal coating, Revestimiento no metálico, Nichtmetallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, A. Metal coatings, B. SEM, B. TEM, B. XRD, and C. Oxidation

To understand the effect of grain refinement on the thermally grown alumina scale adhesion to the metal substrate, two δ-Ni2Al3 coatings, one coarse-grained (~70 μm) and the other ultrafine-grained (generally below ~500 nm), were prepared. The cyclic oxidation in air at 1100 °C shows that the ultrafine-grained (UFG) coating is better oxidation resistant than the coarse-grained (CG) coating due to the formation of a more adherent alumina scale. The latter is intrinsically correlated with the fact that the aluminide grain refinement helps to increase the oxide/metal strength through a route to prevent the formation of large-sized voids at the interface.

Civil engineering, Génie civil, Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Corrosion, Action des agents de corrosion, Corrosion environments, Corrosion, Corrosión, Korrosion, Dépôt électrolytique, Electrodeposition, Depósito electrolítico, Elektroplattieren, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, and Oberflaechenbehandlung

Tin has a strong influence on the electrodeposition of zinc already in concentrations of less than 1 ppm. Tin changes the mechanism, the deposition rate and the morphology of the resulting surface of zinc deposited from an acidic sulfate electrolyte. These severe changes are not obvious since both elements have similar overpotentials for hydrogen evolution as the dominant side reaction. The influence on the electrodeposition of zinc was studied using cyclic voltammetry on a rotating disc electrode, chemical analysis of the zinc layers, chronopotentiometric measurements, and investigations into the microstructure by SEM. It is shown that tin co-deposits with zinc starting at concentrations of about 1 ppm and therefore changes the structure of the zinc layer. A mechanism is presented that explains the significant drop in current efficiency in a pulsed deposition program, in which the codepositing tin acts as cathode during the off cycle leading to drastic anodic redissolution of the zinc.

Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Généralités, General, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Acier haute résistance, High strength steel, Acero alta resistencia, Hochfester Stahl, Microscopie électronique transmission, Transmission electron microscopy, Microscopía electrónica transmisión, Transmissionselektronenmikroskopie, Morphologie, Morphology, Morfología, Résistance mécanique, Strength, Resistencia mecánica, Festigkeit, Spectrométrie photoélectron, Photoelectron spectrometry, Espectrometría fotoelectrón, ESCA Spektrometrie, Structure cristalline, Crystalline structure, Estructura cristalina, Kristallstruktur, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Zingage immersion, Hot dip galvanizing, Galvanización con cinc sumergido, Feuerverzinken, Amorphous oxides, Crystalline oxides, Steel, Transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS)

Annealing of advanced high-strength steel (AHSS) grades often results in surfaces being fully covered by oxides due to alloying elements which diffuse to the steel surface during annealing and which are oxidized there by residual oxygen from the furnace atmosphere. However, these surface oxides tend to significantly hamper the hot-dip galvanizability and are therefore repeatedly under investigation with respect to their morphology and chemical composition for an optimization of the overall galvanizing performance. In the present work two different kinds of AHSS grades are analysed in detail by scanning electron microscopy as well as by X-ray photoelectron spectroscopy and transmission electron microscopy to characterize the formed surface oxides, clearly revealing that it is not only the chemical composition of the oxides influencing their morphology and structure: the oxidation potential of the annealing atmosphere is found to have a significant impact on the surface oxide characteristics, namely the degree of crystallinity, as well. Consequently, these findings can be used to improve the galvanizability of a steel grade by changing the surface oxide morphology.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Corrosion, Action des agents de corrosion, Corrosion environments, Corrosion, Corrosión, Korrosion, Dépôt électrolytique, Electrodeposition, Depósito electrolítico, Elektroplattieren, Désalliage, Dealloying, Desaleación, Microscopie électronique balayage, Scanning electron microscopy, Microscopía electrónica barrido, Rasterelektronenmikroskopie, Synthèse, Synthesis, Síntesis, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, A. Copper, B. SEM, B. XRD, C. De-alloying, and C. Electrodeposited films

Crack-free nanoporous Cu films were synthesized by electrochemical deposition of Cu-Zn alloy films by chronoamperometry (CA) at -0.5 V(Ag/AgCl), followed by a two-step chemical dealloying process. Various nanoporous structures were successfully created with very low concentration of less-noble element (3-4 at.% Zn), by a wet-chemical process. In addition to the Zn, less noble constituent, it is believed that Cu oxide formed during the electrochemical deposition might act as less-noble constituent as well.

Chemical industry parachemical industry, Industrie chimique et parachimique, Mechanics acoustics, Mécanique et acoustique, Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Aluminium alliage, Aluminium alloy, Aluminio aleación, Aluminiumlegierung, Composite matrice métallique, Metal matrix composite, Compuesto matriz metalico, Céramique sans oxyde, Non oxide ceramics, Cerámica sin óxido, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Laser, Láser, Matériau composite, Composite material, Material compuesto, Verbundwerkstoff, Matériau renforcé dispersion, Dispersion reinforced material, Material renforzado dispersión, Dispersionsgehaerteter Werkstoff, Matériau revêtement, Coating material, Material revestimiento, Morphologie, Morphology, Morfología, Nickel alliage, Nickel alloy, Níquel aleación, Nickellegierung, Nitrure de silicium, Silicon nitride, Silicio nitruro, Siliciumnitrid, Propriété mécanique, Mechanical properties, Propiedad mecánica, Préparation, Preparation, Preparación, Vorbereitung, Résistance usure, Wear resistance, Resistencia al desgaste, Verschleissfestigkeit, Titane alliage, Titanium alloy, Titanio aleación, Titanlegierung, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Tribologie, Tribology, Tribología, A. Intermetallics, A. Metal-matrix composites (MMCs), B. Wear, and D. Surface analysis

Si3N4-Ni60 is firstly used to improve the wear resistance of a TA7 (Ti-5Al-2.5Sn) titanium alloy surface by mean of a laser alloying (LA) technique. The synthesis of the hard composite coating on a TA7 titanium alloy by LA of Ni60-Si3N4 pre-placed powders was investigated by means of scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and high resolution transmission electron microscope (HRTEM). Experimental results indicated that a number of the interdendritic lamellar eutectics, nanoscale ceramics (NC) and the amorphous phases were produced in such LA coating. The production of NC led the free energy to enhance, which increased the density of point defect, leading to the formation of hypersaturated state of point defect, causing lattice distortions. Compared with a TA7 alloy substrate, an improvement of the wear resistance was obtained for such LA composite coating.

Civil engineering, Génie civil, Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Corrosion, Action des agents de corrosion, Corrosion environments, Alliage base nickel, Nickel base alloys, Corrosion, Corrosión, Korrosion, Densité, Density, Densidad, Etat supercritique, Supercritical state, Estado supercrítico, Plasma, Projection plasma, Plasma spraying, Proyección plasma, Plasmaspritzen, Projection à chaud, Hot spraying, Proyección en caliente, Spritzen, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, and Oberflaechenbehandlung

In this study, IN625 and a NiCrAlY coated IN625 were tested in high density and low density supercritical water for 500 h.The NiCrAlY coating was applied using plasma spray method. The surfaces were finely polished before testing to assist microstructure observation after testing. The NiCrAlY coated samples were additionally heat treated in air furnace to encourage alumina formation. SEM and XRD analyses were carried out to determine surface microstructure changes, particularly oxide formation. The results showed that when tested under high density supercritical water, the bare IN625 sample suffered from intergranular attacking while low density supercritical water did not have the same effect. Both as-sprayed NiCrAlY and heat treated NiCrAlY did not show any signs of intergranular attack or pitting after being tested in high density and low density supercritical water.

Civil engineering, Génie civil, Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Corrosion, Action des agents de corrosion, Corrosion environments, Alliage base aluminium, Aluminium base alloys, Borure de titane, Titanium boride, Titanio boruro, Titanborid, Corrosion, Corrosión, Korrosion, Dépôt électrolytique, Electrodeposition, Depósito electrolítico, Elektroplattieren, Matériau composite, Composite material, Material compuesto, Verbundwerkstoff, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, and Oberflaechenbehandlung

The electrodeposition behavior of aluminum on TiB2/A356 composite from AlCl3-NaCl-KCl molten salt was studied in this paper. The surface morphology, microstructure, and phase composition of aluminum coating were characterized by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The phase composition of the composite was examined by X-ray diffraction technique. The polarization curves were measured and the corrosion current densities were obtained. The results indicated that the aluminum coating was preferentially electrodeposited on the surface of TiB2 and Si phases. This phenomenon could be largely attributed to the different surface energies of TiB2, Si, and Al phases. With the increasing of deposition time, a continuous, dense, and faceted aluminum coating was finally obtained. It was inferred that the growth of aluminum coating on the surface of the composite was mainly through two-dimensional spreading. However, three-dimensional growth could also be seen. The corrosion current density of the aluminum-coated TiB2/A356 composite (1 min) decreased by an order of magnitude as compared with that of TiB2/A356 composite, and was close to that of A356 alloy, and also in the same order of magnitude with that of pure aluminum. It is evident that, the coverage ofTiB2 and Si phases by aluminum coating (1 min) can effectively improve the corrosion resistance of TiB2/A356 composite. In combination with SEM and EDS results, the behavior can be characterized as preferential electrodeposition.

Crystallography, Cristallographie cristallogenèse, Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Généralités, General, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Assemblage et découpage thermique: aspects métallurgiques, Joining, thermal cutting: metallurgical aspects, Soudage, Welding, Propriétés mécaniques. Rhéologie. Mécanique de la rupture. Tribologie, Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology, Propriété mécanique, Mechanical properties, Propiedad mecánica, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Acier, Steel, Acero, Composé intermétallique, Intermetallic compound, Compuesto intermetálico, Intermetallische Verbindung, Frottement, Friction, Frotamiento, Reibung, Joint recouvrement, Lap joint, Junta recubierta, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Soudage friction, Friction welding, Soldeo por fricción, Reibschweissen, Tôle, Sheet metal, Chapa, and Blech

Multimaterial fabrication such as joining of steel and aluminum is currently prominent in a variety of industries. Friction stir welding is a novel solid-state welding process that causes good joint strength between steel and aluminum. However, the phenomenon contributing significant strength at the interface is not yet clear. In the present study, the interface of the friction stir lap-welded aluminum and coated steel sheet having joint strength maximum (71.4 pct of steel base metal) and minimum, respectively, under two parameter combinations, i.e., 1000 rpm 50 mm min -1 and 500 rpm 100 mm min-1, was exclusively characterized by X-ray diffraction, transmission electron microscopy (TEM), concentration profile, and elemental mapping by electron-probe microanalysis. A TEM-assisted EDS study identifies the morphologies of large size Al13Fe4 and small size Fe3Al-type intermetallic compounds at the interface. The diffusion-induced intermetallic growth (thickness) measured from a backscattered image and concentration profile agreed well with the numerically calculated one. The growth of these two phases at 1000 rpm 50 mm min-1 is attributed to the slower cooling rate (~3.5 K/s) with higher diffusion time (44 seconds) along the interface in comparison to the same for 500 rpm 100 mm min-1 with faster cooling rate (~10 K/s) and less diffusion time (13.6 seconds). The formation of thermodynamically stable and hard intermetallic phase Al13Fe4 at 1000 rpm and travel speed 50 mm min-1 in amounts higher than 500 rpm and a travel speed of 100 mm min-1 results in better joint strength, i.e., 71.4 pct, of the steel base metal.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Corrosion, Action des agents de corrosion, Corrosion environments, Corrosion, Corrosión, Korrosion, Dépôt électrolytique, Electrodeposition, Depósito electrolítico, Elektroplattieren, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Résistance corrosion, Corrosion resistance, Resistencia corrosión, Korrosionsbestaendigkeit, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, NiFe films, and Saturation magnetisation

NiFe alloy films were prepared by galvanostatic electrodeposition method on a copper substrate under various deposition temperature and current density. The structure and surface morphology of electrodeposited NiFe films were analysed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Vibrating sample magnetometer and electrochemical workstation was used to obtain the magnetic and corrosion behaviours of the NiFe thin film. The results showed that the NiFe particle size was ranging from 10 to 30 nm. The main phase of NiFe thin films was fcc (FeNi3) structure. NiFe thin films prepared under the condition of temperature (60°C) and current density (167 A m―2) possessed low coercivity (0·18 kA m―1) and high specific saturation magnetisation (253 Am2 kg―1).

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Agitation mécanique, Stirring, Agitación mecánica, Dépôt électrolytique, Electrodeposition, Depósito electrolítico, Elektroplattieren, Epaisseur, Thickness, Espesor, Dicke, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Aluminium, Anodising, Coating, and Ionic

Aluminium coatings were electrodeposited on Fe9Cr1Mo steel from AlCl3-1-ethyl-3-methyl imidazolium chloride ionic liquid at room temperature and the effect of solution stirring on deposition rate, preferred crystal orientation, surface morphology and roughness have been investigated. Aluminium coating could not be obtained in the unstirred solution for a deposition current density of 20 mA cm-2 or higher. However, vigorous stirring of the bath enabled the deposition at a current density of 20 mA cm-2 or higher, along with a significant increase in coating thickness. On the other hand, roughness of the coating increased at higher stirring speeds. X-ray diffraction measurement showed 26% increase in normalised intensity of (111) reflection on increasing the stirring speed up to 800 rev min-1, whereas the intensity of (200) reflection was found to be decreased by 37%. Scanning electron microscopy and energy dispersive X-ray analysis of the anodised aluminium showed formation of less porous aluminium oxide film.

Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Généralités, General, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Aimantation, Magnetization, Imanación, Magnetisieren, Domaine magnétique, Magnetic domain, Dominio magnético, Magnetische Domaene, Dépôt électrolytique, Electrodeposition, Depósito electrolítico, Elektroplattieren, Propriété magnétique, Magnetic properties, Propiedad magnética, Magnetische Eigenschaft, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Co―Pt nanotubes, In-field magnetic force microscopy, and Magnetization distribution

Using template-assisted electrodeposition in partially Au-covered polycarbonate templates, we have successfully deposited equiatomic Co-Pt nanotubes with an external radius R of 100 nm, lengths L of 800―2000 nm and tube-wall thicknesses of 70 nm. By applying different characterization methods ― vibrating-sample magnetometry and combined atomic and magnetic force microscopy ― we have shown that in as-deposited face-centred cubic Co-Pt nanotubes the magnetization in the remanent state can be described with a vortex-type of closure. Such curling of the magnetization distribution has its origin in the minimization of the demagnetizing field that arises from the surface or volume charges. The demagnetization of single-vortex-type nanotubes proceeds gradually and exhibits only a modest hysteresis. Such nanotubes with a single vortex-type of magnetization distribution possess the unique property of emitting no stray fields in the remanent state, despite their elongated shape, and therefore represent perfect candidates for magnetoresistive random-access-memory devices and for biomedical applications such as targeted drug delivery.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Dépôt de matériaux non métalliques, Nonmetallic coatings, Corrosion, Action des agents de corrosion, Corrosion environments, Alliage base titane, Titanium base alloys, Aluminium alliage, Aluminium alloy, Aluminio aleación, Aluminiumlegierung, Apatite hydroxylée, Hydroxyapatite, Hidroxiapatito, Biomatériau, Biomaterial, Corrosion électrochimique, Electrochemical corrosion, Corrosión electroquímica, Elektrochemische Korrosion, Couche oxyde, Oxide layer, Capa óxido, Oxidschicht, Dépôt électrolytique, Electrodeposition, Depósito electrolítico, Elektroplattieren, Impédance, Impedance, Impedancia, Microscopie électronique balayage, Scanning electron microscopy, Microscopía electrónica barrido, Rasterelektronenmikroskopie, Oxyde anodique, Anodic oxide, Oxido anódico, Oxyde de titane, Titanium oxide, Titanio óxido, Titanoxid, Revêtement non métallique, Non metal coating, Revestimiento no metálico, Nichtmetallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Vanadium alliage, Vanadium alloy, Vanadio aleación, Vanadiumlegierung, A. Titanium alloy, B. EIS, B. SEM, C. Anodic films, and C. Electrodeposited films

In order to improve the bonding strength between hydroxyapatite (HA) coating and Ti-6Al-4V substrate, a uniform titanium oxide film was obtained by controlled anodic oxidation. After that an alkaline treatment with NaOH solution was used to make them more bioactive. Finally hydroxyapatite coating has been prepared on Ti-6Al-4V substrate through electrochemical deposition. Comparative electrochemical behaviour of untreated and surface modified Ti-6Al-4V alloy, in bio-simulated fluid solution was investigated by electrochemical techniques. SEM was used to observe the morphology of modified surfaces and the thicknesses of the oxide films prepared were evaluated on the cross-sections of the samples using SEM-FIB.