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Electrical engineering, Electrotechnique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Electrotechnique. Electroenergetique, Electrical engineering. Electrical power engineering, Matériel électrique divers, Various equipment and components, Condensateurs. Résistances. Filtres, Capacitors. Resistors. Filters, Aluminium Phosphate, Aluminium Phosphates, Aluminio Fosfato, Composé ternaire, Ternary compound, Compuesto ternario, Condensateur électrochimique, Electrolytic capacitor, Condensador electroquímico, Couche ultramince, Ultrathin films, Evaluation performance, Performance evaluation, Evaluación prestación, Forme cylindrique, Cylindrical shape, Forma cilíndrica, Gonflement, Swelling, Inflamiento, Lithium Oxyde, Lithium Oxides, Litio Óxido, Lithium Titanate, Lithium Titanates, Litio Titanato, Matériau modifié, Modified material, Material modificado, Matériau revêtu, Coated material, Material revestido, Performance, Rendimiento, Revêtement, Coatings, Revestimiento, Supercondensateur, Supercapacitor, Supercondensador, Titane Oxyde, Titanium Oxides, Titanio Óxido, Traitement surface, Surface treatment, Tratamiento superficie, Li4Ti5O12, H2Ti12O25, Hybrid supercapacitor, Surface modified, and Swollen phenomenon

Hydrogen titanium oxide, H2Ti12O25 is prepared by soft chemical method. A fabricated asymmetric hybrid supercapacitor using an AlPO4 modified H2Ti12O25 anode shows electrochemical performance superior to a Li4Ti5O12 anode, including cycling performance. The anode comprised of H2Ti12O25 coated with 3 wt.% AlPO4 shows the energy and power density of 41.1 Wh kg-1, 194.1 W kg-1, respectively, at a current rate of 0.1 A g-1 as well as the highest cycling performance, with 94.1% specific capacitance retained after 1000 cycles at a current rate of 3.0 A g-1. These excellent results are convincing evidence that H2Ti12O25 should be regarded as one of the more promising anode materials.

Electrical engineering, Electrotechnique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Electrotechnique. Electroenergetique, Electrical engineering. Electrical power engineering, Electroénergétique, Electrical power engineering, Conversion directe et accumulation d'énergie, Direct energy conversion and energy accumulation, Conversion électrochimique: piles et accumulateurs électrochimiques, piles à combustibles, Electrochemical conversion: primary and secondary batteries, fuel cells, Energie, Energy, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Appareils de production et de conversion d'énergie: énergie thermique, énergie électrique, énergie mécanique, etc, Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc, Piles à combustible, Fuel cells, Alcool primaire, Primary alcohol, Alcohol primario, Collection courant, Current collection, Colección corriente, Gestion eau, Water management, Gestión del agua, Métal, Metal, Méthanol, Methanol, Metanol, Noyage, Flooding, Inundación, Oxydation, Oxidation, Oxidación, Pile combustible alcool, Alcohol fuel cells, Traitement par plasma, Plasma assisted processing, Traitement surface, Surface treatment, Tratamiento superficie, Collecteur de courant, Current collector, Direct methanol fuel cell, Plasma electrolytic oxidation, and Water flooding

A novel water management system for micro passive DMFC is fabricated and characterized in this paper. This system consists of both a cathode current collector made of a 316L sintered stainless fiber felt (SSFF) and an aluminum-based end plate fabricated with a perforated flow field. Besides, some water-collecting channels were fabricated on the surface of the cathode end plate and then covered by the plasma electrolytic oxidation (PEO) coating. The results show that the PEO coating plays crucial roles in the water management system. Because of the highly hydrophilic property of the coating, the channels work well in collecting the liquid water from the current collector, and water accumulation along the air-breathing holes can be well prevented, which improves the stability of the micro DMFC.

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 matériaux non métalliques, Nonmetallic coatings, Barrière thermique, Thermal barrier, Barrera térmica, Conductivité thermique, Thermal conductivity, Conductividad térmica, Waermeleitfaehigkeit, Dilatation thermique, Thermal expansion, Dilatación térmica, Thermische Ausdehnung, Dopage, Doping, Dopen, Expansion, Expansión, Oxyde d'yttrium, Yttrium oxide, Ytrio óxido, Yttriumoxid, Perovskite, Perovskita, Revêtement non métallique, Non metal coating, Revestimiento no metálico, Nichtmetallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, TBC, perovskites, thermal conductivity, and thermal expansion

Y2O3 and Yb2O3 co-doped strontium hafnate powder with chemistry of Sr(Hf0.9Y0.05Yb0.05)O2.95 (SHYY) was synthesized by a solid-state reaction at 1450 °C. The SHYY showed good phase stability not only from 200 to 1400 °C but also at a high temperature of 1450 °C for a long period, analyzed by differential scanning calorimetry and x-ray diffraction, respectively. The coefficient of thermal expansion of the sintered bulk SHYY was recorded by a high-temperature dilatometer and revealed a positive influence on phase transitions of SrHfO3 by co-doping with Y2O3 and Yb2O3. The thermal conductivity of the bulk SHYY was approximately 16% lower in contrast to that of SrHfO3 at 1000 °C. Good chemical compatibility was observed for SHYY with 8YSZ or Al2O3 powders after a 24 h heat treatment at 1250 °C. The phase stability and the microstructure evolution of the as-sprayed SHYY coating during annealing at 1400 °C were also investigated.

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, Argent, Silver, Plata, Silber, Choc laser, Laser impact, Choque laser, Dépôt projection, Spray coating, Depósito proyección, Spritzbeschichten, Matériau composite, Composite material, Material compuesto, Verbundwerkstoff, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Cold spray, Composite, Laser shock, Oxide, Powder, Splat, and Tantalum

Since the major technological issues in cold spray are now controlled, the key parameter for successful coating relates to the powder. The influence of the main characteristics of the starting powder on the final coating properties remains rather unknown. This includes primarily metallurgical, morphological and physico-chemical characteristics of the particles. This article focuses on the so-called local approach to these characteristics to show that the current global approach is insufficient. The discussion is based on many examples of cold spray results, including recent work on Ag-based and Ta cold sprayed-coatings. This results in proposed specifications for powders which are claimed to be tailored for cold spray.

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 et alliages frittés. Cermets, Sintered metals and alloys. Pseudo alloys. Cermets, Traitements de surface, Surface treatment, Corrosion, Action des agents de corrosion, Corrosion environments, 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, Composé intermétallique, Intermetallic compound, Compuesto intermetálico, Intermetallische Verbindung, Corrosion électrochimique, Electrochemical corrosion, Corrosión electroquímica, Elektrochemische Korrosion, Frittage, Sintering, Sinterización, Sintern, Microstructure, Microestructura, Mikrogefuege, Métallurgie poudre, Powder metallurgy, Metalurgia polvo, Pulvermetallurgie, Revêtement, Coatings, Revestimiento, Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Tribologie, Tribology, Tribología, Usure, Wear, Desgaste, Verschleiss, Corrosion, and Intermetallics

An erbium modified Mg17Al12 based coating was fabricated by hot press sintering on as extruded AZ61 Mg alloy. The Er modified coating was composed of Mg17Al12 and Al3Er phases. As a result of the presence of the dispersed Al3Er phase, the coating had a greater microhardness than Mg17Al12. Thermal effects of sintering at 400°C for 1 h caused no obvious deterioration in the wear resistance of the AZ61 Mg matrix. Electrochemical and wear resistance tests showed that the Er modified Mg17Al12 based coating had a lower corrosion current density and a lower friction coefficient than Mg17Al12, the AZ61 Mg matrix and a thermal diffusion coating (TDC). The superior wear resistance of the sintered coating resulted from the hard Al3Er phase. The corrosion resistance of the sintered coating was better than that of the TDC as a result of suppression of hydrogen evolution by the rare earth metal Er.

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, 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, Contrainte résiduelle, Residual stress, Tensión residual, Eigenspannung, Dépôt projection, Spray coating, Depósito proyección, Spritzbeschichten, Projection à chaud, Hot spraying, Proyección en caliente, Spritzen, Revêtement, Coatings, Revestimiento, Ueberzug, Résistance usure, Wear resistance, Resistencia al desgaste, Verschleissfestigkeit, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Tribologie, Tribology, Tribología, Usure, Wear, Desgaste, Verschleiss, iron alloys, residual stress, robot, and wear resistance

Even though the application of thermal spray coatings on complex geometries gained a greater interest in the last decade, the effect of different geometrical features on the wear behavior is still ill-defined. In this study, the wear resistance of FTC-FeCSiMn coated 3D surfaces was investigated. The wear test was carried out by means of two innovative testing procedures. The first test is a Pin-on-Tubes test where the rotating motion is realized by a lathe chuck. The specimens in the second test were fixed on the table and a robot arm operated the pin. This wear test was applied on specimens with concave or convex surfaces. The residual stresses, which were determined by means of an incremental hole-drilling method, show a dependency on the substrate geometry. The obtained stresses were put in relation to the different radii. After the wear test, a 3D-profilometer determined the wear volume and the sections of the coatings were characterized by a scanning electron microscope. The results indicate that the wear resistance is strongly influenced by the geometry of the substrate.

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, Alliage base titane, Titanium base alloys, Aluminium alliage, Aluminium alloy, Aluminio aleación, Aluminiumlegierung, Dépôt projection, Spray coating, Depósito proyección, Spritzbeschichten, Formage projection, Spray forming, Formación proyección, Formage à tiède, Warm forming, Modelado en tibio, Halbwarmumformen, Microstructure, Microestructura, Mikrogefuege, Porosité, Porosity, Porosidad, Porositaet, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Vanadium alliage, Vanadium alloy, Vanadio aleación, Vanadiumlegierung, microstructure, oxygen content, porosity, and warm spraying

Warm spray (WS) is a modification of high-velocity oxy-fuel spraying, in which the temperature of the supersonic gas flow generated by the combustion of kerosene and oxygen is controlled by diluting the combustion flame with an inert gas such as nitrogen. The inert gas is injected into the mixing chamber placed between the combustion chamber and the powder feed ports, thus the temperature of the propellant gas can be controlled from ∼700 to 2,000 K. Since WS allows for higher particle temperatures in comparison to cold spray, warm sprayed particles are more softened upon impact, thus resulting in greater deformation facilitating the formation of shear instability for bonding. Recently, the combustion pressure of WS has been increased from 1 (low-pressure warm spray) to 4 MPa (high-pressure warm spray) in order to increase the velocity of sprayed particles. Effects of spray parameters on microstructure, mechanical properties, and splats formation of Ti-6Al-4V were systematically studied. Obtained coatings were examined by analyzing the coating cross-section images, microhardness as well as oxygen content. In addition, flattening ratio of splats was calculated as a function of nitrogen flow rate. It was found that the increased particle velocity caused by the increased combustion pressure had significant beneficial effects in terms of improving density and controlling the oxygen level in the sprayed Ti-6Al-4V coatings.

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.

Electronics, Electronique, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Science des matériaux, Materials science, Méthodes de nanofabrication, Methods of nanofabrication, Formation de nanomotifs, Nanoscale pattern formation, Traitements de surface, Surface treatments, Sciences appliquees, Applied sciences, Electronique, Electronics, Electronique des semiconducteurs. Microélectronique. Optoélectronique. Dispositifs à l'état solide, Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices, Dispositifs à ondes acoustiques, piézoélectriques, piézorésistifs, Acoustic wave devices, piezoelectric and piezoresistive devices, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Surface treatment, Composé III-VI, III-VI compound, Compuesto III-VI, Alumine, Alumina, Alúmina, Tonerde, Aluminium, Aluminio, Angle contact, Contact angle, Angulo contacto, Kontaktwinkel, Anodisation, Anodizing, Anodización, Elektrolytisches Oxidieren, Courant intense, High strength current, Corriente intensa, Diminution coût, Cost lowering, Reducción costes, Kostensenkung, Dispositif entraînement, Driving device, Dispositivo arrastre, Durcissement, Hardening, Endurecimiento, Haerten, Electrolyte acide, Acid electrolyte, Electrólito ácido, Evaluation performance, Performance evaluation, Evaluación prestación, Formation nanomotif, Nanopatterning, Formacíon nanomotivo, Gyroscope, Giroscopio, Microscopie électronique balayage, Scanning electron microscopy, Microscopía electrónica barrido, Rasterelektronenmikroskopie, Nanocomposite, Nanocompuesto, Nanofil, Nanowires, Nanostructure, Nanoestructura, Précision élevée, High precision, Precisión elevada, Rotor, Surface rugueuse, Rough surface, Superficie rugosa, Rauhe Oberflaeche, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Traitement(durcissement), Curing, Vitesse déplacement, Speed, Velocidad desplazamiento, Geschwindigkeit, 0707D, 8107B, 8107V, 8116R, Al2O3, Matériau nanostructuré, Nanostructured material, Drag reduction, Liquid-floated rotor gyroscope, Nanostructured, and Oleophobic

Liquid-floated rotor gyroscopes can provide high accuracy at small volume and low cost. In rotor gyroscopes, the rotating speed of rotor can significantly affect the detection accuracy. This work presents a new kind of liquid-floated rotor gyroscope using super-oleophobic surface processing, which can improve the performance of driving system. In this work, an unconventional anodization in oxalic-acid electrolyte under high current was employed to fabricate diverse nanostructured alumina surfaces. The top-view SEM image shows the nanowire pyramid structure on the surface of processed sample. Modification of the rough surfaces was achieved by dipping substrates in 0.5 wt% 1H,1H,2H,2H-perfluoro-octadecyltrichlorosilane-in-hexane and then curing then at 120 °C for 1 h. The maximum contact angle (CA) of the aluminum rotor with nanowire pyramid structure was measured to be 156° in average. The oleophobicity of the rotor surface was used to reduce the resistance in the floating liquid. The test results show that, under the normal working state, the rotating speed of super-oleophobic rotor can be reached up to 3200 rpm. While a similar system without the micro-nano composite structure can only reach 2860 rpm. Thus, the nanostructured super-oleophobic alumina surface processing can greatly increase the rotating speed, thereby improving the performance of the gyro system.

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, Techniques de l'ingénieur appliqués à la métallurgie. Applications. Divers, Engineering techniques in metallurgy. Applications. Other aspects, Applications, Industrie automobile, Automotive engineering, Adhérence, Adhesion, Adherencia, Adhaesion, Application, Aplicación, Anwendung, Force adhérence, Adhesive strength, Fuerza adherencia, Haftfestigkeit, Industrie automobile, Automobile industry, Industria automóvil, Autoindustrie, Industrie aéronautique, Aeronautic industry, Industria aeronáutica, Luftfahrtindustrie, Morphologie, Morphology, Morfología, Plasma, Projection plasma, Plasma spraying, Proyección plasma, Plasmaspritzen, Projection à chaud, Hot spraying, Proyección en caliente, Spritzen, Revêtement conducteur, Conductive coating, Revestimiento conductor, Résistance mécanique, Strength, Resistencia mecánica, Festigkeit, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Adhesion testing, aircraft, atmospheric plasma spray (APS), automotive, copper, and electrically conductive coatings

Metallization of Carbon Fiber-Reinforced Polymer (CFRP) composites aggrandized their application to aircraft, automobile, and wind power industries. Recently, the metallization of CFRP surface using thermal spray technique, especially the cold spray, a solid state deposition technique, is a topic of research. However, a direct cold spray deposition on the CFRP substrate often imposes severe erosion on the surface owing to the high-impact energy of the sprayed particles. This urges the requirement of an interlayer on the CFRP surface. In the present study, the effect of surface treatment on the interlayer adhesion strength is evaluated. The CFRP samples were initially treated mechanically, chemically, and thermally and then an interlayer was developed by atmospheric plasma spray system. The quality of the coating is highly dependent on the splat taxonomy; therefore the present work also devoted to study the splat formation behavior using the splat-collection experiments, where the molten Cu particles impinged on the treated CFRP substrates. These results were correlated with the coating adhesion strength. The coating adhesion strength was measured by pull-out test. The results showed that the surface treatment, particularly the chemical treatment, was fairly successful in improving the adhesion strength.

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, Formage, Forming, Laminage, Rolling, Traitements de surface, Surface treatment, Corrosion, Action des agents de corrosion, Corrosion environments, Protection contre la corrosion, Corrosion prevention, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Application, Aplicación, Anwendung, Corrosion, Corrosión, Korrosion, Formage, Forming, Conformado, Umformen, Impédance, Impedance, Impedancia, Laminage à froid, Cold rolling, Laminado en frío, Kaltwalzen, Matériau composite, Composite material, Material compuesto, Verbundwerkstoff, Microscopie force atomique, Atomic force microscopy, Microscopía fuerza atómica, Oxyde de fer, Iron oxide, Hierro óxido, Eisenoxid, Passivation, Pasivación, Passivierung, Polarisation anodique, Anodic polarization, Polarización anódica, Anodische Polarisation, Polymère, Polymer, Polímero, Protection corrosion, Corrosion protection, Protección corrosión, Korrosionsschutz, Pyrrole polymère, Pyrrole polymer, Pirrol polímero, Revêtement composite, Composite coating, Revestimiento compuesto, Synthèse, Synthesis, Síntesis, Tôle laminée à froid, Cold rolled sheet, Chapa laminada en frío, Kaltgewalztes Blech, anodic polarization, composite coatings, conducting atomic force microscopy, conducting polymers, corrosion, electrochemical impedance spectroscopy, micaceous iron oxide, passivation, and polypyrrole

Novel hybrid composite pigments consisting of micaceous iron oxide (MIOX) and polypyrrole (PPy) were synthesized using a chemical oxidative polymerization method and water as a reaction medium. Three different particle sizes (5, 10, and 30 μm) of MIOX, namely. MIOX5, MIOX10, and MIOX30, were used for the synthesis of MIOX/PPy composite pigments. The synthesized hybrid composite pigment was characterized by scanning electron microscopy (SEM) for morphology, energy-dispersive spectroscopy (EDS) for elemental analysis, four-point probe conductivity, and conductive-atomic force microscopy (C-AFM) for conductivity studies. Density tests were also performed for the adhesion between MIOX and PPy. MIOX30/ PPy composite pigment-based coatings were formulated at 15, 25, and 35% pigment volume concentration (PVC) on cold-rolled steel and were exposed to salt spray test conditions according to ASTM B117. Corrosion performance was analyzed by electrochemical impedance spectroscopy (EIS) and anodic polarization. Equivalent circuit modeling of the EIS data was performed for the understanding of the corrosion processes on the coated substrate. A smaller drop in impedance was observed for MIOX30/PPy composite pigment-based coating at 100 days of salt spray exposure than MIOX30 pigment coating for the same duration of exposure.

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, Corrosion, Action des agents de corrosion, Corrosion environments, Corrosion, Corrosión, Korrosion, Dépôt projection, Spray coating, Depósito proyección, Spritzbeschichten, Projection à chaud, Hot spraying, Proyección en caliente, Spritzen, Revêtement, Coatings, Revestimiento, Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Coating, Properties, Resistance, Spraying, and Structure

Coating technology is growing because of its important role in improving, e.g. corrosion resistance, thermal and electrical conductivities, and other properties of material in order to decrease costs and increase service life and safety. Cold spraying is the technique to produce coatings from powder feedstock by spraying solid particles on the substrate, forming the coating. Cold spraying is a relatively new spraying method, which has many advantages over other forms of thermal spraying. The advantages are dense and pure structures, high deposition efficiency, low residual stresses, minimal heat input to substrate, phase and compositional stability, and little need for masking. Furthermore, cold spraying is a cost effective and environmentally friendly alternative to, e.g. soldering, electroplating, and painting. One potential application field of cold sprayed coatings is corrosion protection due to the possibility to produce fully dense and impermeable coatings. From this aspect, this review is focused on corrosion properties of cold sprayed coatings and structural details behind these coatings.

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, Propriétés mécaniques. Rhéologie. Mécanique de la rupture. Tribologie, Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology, Adhérence, Adhesion, Adherencia, Adhaesion, Alumine, Alumina, Alúmina, Tonerde, Dépôt projection, Spray coating, Depósito proyección, Spritzbeschichten, Haute résolution, High resolution, Alta resolucion, Microscopie électronique transmission, Transmission electron microscopy, Microscopía electrónica transmisión, Transmissionselektronenmikroskopie, Mécanisme formation, Formation mechanism, Mecanismo formacion, Projection à chaud, Hot spraying, Proyección en caliente, Spritzen, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété traction, Tensile property, Propiedad tracción, Zugeigenschaft, Revêtement, Coatings, Revestimiento, Ueberzug, Résistance mécanique, Strength, Resistencia mecánica, Festigkeit, Résistance traction, Tensile strength, Resistencia tracción, Zugfestigkeit, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, HRTEM, adhesion, alumina, aluminum, cold gas spraying (CGS), and tensile strength

The metallization of ceramics by means of cold gas spraying (CGS) has been in the focus of numerous publications in the recent past. However, the bonding mechanism of metallic coatings on non-ductile substrates is still not fully understood. Former investigations of titanium coatings deposited on corundum revealed that a combination of recrystallization induced by adiabatic shear processes and hetero-epitaxial growth might be responsible for the high adhesion strengths of coatings applied on smooth ceramic surfaces. In the present work, the interface formation between CGS aluminum and alumina substrates is examined for different particle sizes and substrate temperatures. Furthermore, the influence of subsequent heat treatment on tensile strength and hardness is investigated. The splat formation of single particles is examined by means of scanning electron microscopy, while a high resolution transmission electron microscope is used to study the Al/Al2O3 interface. First results suggest that mechanical interlocking is the primary adhesion mechanism on polycrystalline substrates having the roughness in sub-micrometer range, while the heteroepitaxy between Al and Al2O3 can be considered as the main bonding mechanism for single-crystalline sapphire (α-Al2O3) substrates with the surface roughness in nanometer range. The heteroepitaxial growth is facilitated by deformation-induced recrystallisation of CGS aluminum.

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, Carbure de tungstène, Tungsten carbide, Wolframio carburo, Wolframcarbid, Carbure fritté, Cemented carbides, Carburo sinterizado, Hartmetall, Cobalt, Cobalto, Dépôt projection, Spray coating, Depósito proyección, Spritzbeschichten, Ecaillage, Scaling, Escamadura, Nanostructure, Nanoestructura, Poudre fine, Fine powder, Polvo fino, Projection HVOF, HVOF spraying, Proyeccion HVOF, Projection à chaud, Hot spraying, Proyección en caliente, Spritzen, Revêtement, Coatings, Revestimiento, Ueberzug, Résistance usure, Wear resistance, Resistencia al desgaste, Verschleissfestigkeit, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Tribologie, Tribology, Tribología, Usure glissement, Sliding wear, Desgaste deslizamiento, Gleitverschleiss, Usure roulement, Rolling wear, Desgaste rodadura, Waelzverschleiss, Fine structured coatings, HVOF, Nanostructured coatings, Scaling effects, WC-Co, Wear effects, Wear resistant coatings, and Wear testing

Fine structured and nanostructured materials represent a promising class of feedstock for future applications, which has also attracted increasing interest in the thermal spray technology. Within the field of wear protection, the application of fine structured or nanostructured WC-Co powders in the High Velocity Oxy-Fuel flame spraying technique (HVOF) provides novel possibilities for the manufacturing of cermet coatings with improved mechanical and tribological characteristics. In this study the tribological behavior of HVOF sprayed coatings derived from conventional, fine and nanostructured WC-12Co powders under sliding and rolling wear are investigated and the results are compared to C45 steel (Mat.-No. 1.0503). In addition, sliding and rolling wear effects on a microscopic level are scrutinized. It has been shown that under optimized spray conditions the corresponding fine and nanostructured WC-12Co coatings are able to obtain higher wear resistances and lower friction coefficients than the conventional coatings. This can be attributed to several scaling effects of the microstructure and to the phase evolution of the coating, which are discussed.

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, A froid, Cold process, En frío, Dynamique fluide, Fluid dynamics, Dinámica fluido, Dépôt projection, Spray coating, Depósito proyección, Spritzbeschichten, Formage à froid, Cold forming, Modelado en frio, Kaltformgeben, Préchauffage, Preheating, Precalentamiento, Vorwaermen, Revêtement, Coatings, Revestimiento, Ueberzug, Simulation numérique, Numerical simulation, Simulación numérica, Température, Temperature, Temperatura, Temperatur, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Carrier gas, Coating, Cold spray, and Computational fluid dynamics

Carrier gas is known as the medium to inject the cold sprayed powders into the main driving flow inside the nozzle. Hence, the properties and conditions of carrier gas should be of great importance to the particle motion behaviour and then particle deposition process. In this study, the effect of carrier gas temperature on the particle acceleration and deposition in cold spray process was investigated by both numerical and experimental methods. It is found that the supersonic driving gas flow and the consequent particle acceleration behaviour are significantly influenced by the carrier gas temperature, more specifically, higher carrier gas temperature results in higher particle impact velocity. In addition, because the carrier gas has additional heating effect on the powder particles before injection, the final impact temperature also increases with the carrier gas temperature, which leads to the reduction in the critical velocity. The increase in particle impact velocity and reduction in critical velocity enable the deposition efficiency and coating bonding strength to significantly improve as the carrier gas temperature increases. The particle impact velocity is found to be more influential than critical velocity reduction.

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 matériaux non métalliques, Nonmetallic coatings, Corrosion, Action des agents de corrosion, Corrosion environments, Protection contre la corrosion, Corrosion prevention, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Composé organique, Organic compounds, Compuesto orgánico, Organische Verbindung, Corrosion, Corrosión, Korrosion, Couche protectrice, Protective layer, Capa protectora, Schutzschicht, Protection corrosion, Corrosion protection, Protección corrosión, Korrosionsschutz, Revêtement non métallique, Non metal coating, Revestimiento no metálico, Nichtmetallischer Ueberzug, Revêtement protecteur, Protective coatings, Revestimiento protector, Schutzueberzug, Système intelligent, Intelligent system, Sistema inteligente, coatings, corrosion, multifunctional, nanoscale materials, self-healing, and smart materials

Development of materials possessing the ability to recover their main function(s) in response to destructive impacts is, today, one of most rapidly growing fields in material science. In particular, protective organic coatings with the features to heal or restore their protective function autonomously are of great interest infighting surface deterioration processes like corrosion, biofouling, and other affecting metallic structures. Embedding of micro- and nanocontainers in protective coatings is a frequently used technique nowadays to provide them one or several feedback-active functionalities. Depending on the container's morphology and active agent(s) filled, coatings with specifically aimed self-recovering functionalities (anticorrosive, water-repelling, antifouling, etc.) or multifunctional coatings can be created. In the present paper, different types of containers for self-recovering functional coatings synthesized by use of mesoporous nano- and microparticles or on the emulsion basis are presented. L-b-L polyelectrolyte deposition, interfacial polymerization, surface precipitation, Pickering emulsions, and in situ emulsion polymerization were utilized for the preparation of nano- or micro-scaled containers. Morphology of containers, efficiency of encapsulation, and kinetics of active agents release were investigated using modem techniques such as transmission mode in the scanning electron microscopy (T-SEM), cryo scanning electron microscopy (Cryo-SEM), etc. Incorporation of containers in the coating matrix was followed by the experimental modeling of external impacts, leading to simultaneous container damage. Subsequent release of the active agent at the affected site caused the active feedback of the coating and self-recovery of its specific protective function. The advantages of novel container-based protective coatings as compared to conventional ones are illustrated by corrosion tests results according to ASTM Standard B117.

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, Cémentation caisse, Pack carburizing, Cementación en paquete, Pulveraufkohlen, Dépôt chimique phase vapeur, Chemical vapor deposition, Depósito químico fase vapor, Chemisches Aufdampfen, Dépôt chimique, Chemical deposition, Depósito químico, Stromloses Beschichten, Microscopie électronique balayage, Scanning electron microscopy, Microscopía electrónica barrido, Rasterelektronenmikroskopie, Oxydation, Oxidation, Oxidación, Protection, Protección, Revêtement, Coatings, Revestimiento, Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Chemical vapour deposition, SEM, TG, and XRD

The growth of Mg and Al coatings on copper by pack cementation is examined in this work by investigating the mechanism of the process, the effect of temperature and heating time on the coating structure. The experiments were undertaken at temperatures ranging from 550 to 600°C, while the duration of the process varied from 30 min to 3 h. It was found that the magnesium coatings consist of two phases corresponding to MgCu2 and CuMg2. These phases appeared as distinguished layers or mixed with each other, depending on the deposition temperature and duration. On the other hand, the aluminium coatings consist of a single Al4Cu9 phase whose thickness increases with deposition time and temperature. Finally, the oxidation resistance was also evaluated by thermogravimetric measurements, which revealed that the coated samples have superior resistance to bare copper, while Al coated coupons had the best performance when exposed in high temperature environment.

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, Propriétés mécaniques. Rhéologie. Mécanique de la rupture. Tribologie, Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology, Matériau composite, Composite material, Material compuesto, Verbundwerkstoff, Condition opératoire, Operating conditions, Condición operatoria, Dépôt projection, Spray coating, Depósito proyección, Spritzbeschichten, Grosseur grain, Grain size, Grosor grano, Korngroesse, Microstructure, Microestructura, Mikrogefuege, Nanocomposite, Nanocompuesto, Propriété mécanique, Mechanical properties, Propiedad mecánica, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, cold spray, mechanical properties, microstructural behavior, nanocomposites, and processing parameters

Cold spray is a coating technology based on aerodynamics and high-speed impact dynamics. In this process, spray particles (usually 1-50 μm in diameter) are accelerated to a high velocity (typically 300-1200 m/s) by a high-speed gas (pre-heated air, nitrogen, or helium) flow that is generated through a convergent-divergent de Laval-type nozzle. A coating is formed through the intensive plastic deformation of particles impacting on a substrate at a temperature below the melting point of the spray material. In the present paper the main processing parameters affecting the microstructural and mechanical behavior of metal-metal cold spray deposits are described. The effect of process parameters on grain refinement and mechanical properties were analyzed for composite particles of Al-Al2O3, Ni-BN, Cu-Al2O3, and Co-SiC. The properties of the formed nanocomposites were compared with those of the parent materials sprayed under the same conditions. The process conditions, leading to a strong grain refinement with an acceptable level of the deposit mechanical properties such as porosity and adhesion strength, are discussed.

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, Alliage base aluminium, Aluminium base alloys, Alliage base magnésium, Magnesium base alloys, Dépôt projection, Spray coating, Depósito proyección, Spritzbeschichten, Projection à chaud, Hot spraying, Proyección en caliente, Spritzen, Revêtement, Coatings, Revestimiento, Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Aluminium, Coating, Magnesium, Optimisation, and Spray

Cold spray technology continues to attract increasing attention in surface modification of light metals due to its low temperature operation. A method for selecting optimum process parameters is presented for cold spraying of aluminium coatings upon magnesium alloy AZ91. In the present study, particle deposition behaviour is investigated via modifying spraying parameters. Subsequently, based on the relationship between bonding ratio and particle velocity, the critical particle velocity for successful adhesion is determined. Finally, the influence of particle velocity on key coating characteristics is examined, including coating porosity, hardness, deposition efficiency and bond strength.