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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, Alliage base titane, Titanium base alloys, Aluminium alliage, Aluminium alloy, Aluminio aleación, Aluminiumlegierung, Propriété surface, Surface properties, Propiedad superficie, Oberflaecheneigenschaft, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Vanadium alliage, Vanadium alloy, Vanadio aleación, and Vanadiumlegierung

In this research, the effect of various surface treatments including laser processing, grit blasting and anodizing on chemical structure, surface topography, and bioactivity of Ti-6Al-4V was investigated. Six groups of samples were prepared by a combination of two alternative laser processes, grit blasting and anodizing. Selected samples were first evaluated using microanalysis techniques and contact roughness testing and were then exposed to in vitro environment. Scanning electron microscopy was used to characterize the corresponding final surface morphologies. Weight measurement and atomic absorption tests were employed for determination of bioactivity limits of different surface conditions. Based on the data obtained in this study, low-energy laser processing generally yields a better biological response. The maximum bioactivity was attained in those samples exposed to a three step treatment including low-energy laser treatment followed by grit blasting and anodizing.

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.

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, Propriétés mécaniques. Rhéologie. Mécanique de la rupture. Tribologie, Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology, Rupture, Fractures, Matériau composite, Composite material, Material compuesto, Verbundwerkstoff, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Alliage base aluminium, Aluminium base alloys, Durcissement déformation, Strain hardening, Endurecimiento deformación, Verfestigung, Ecrouissage, Work hardening, Endurecimiento en frío, Frottement, Friction, Frotamiento, Reibung, Magnésium alliage, Magnesium alloy, Magnesio aleación, Magnesiumlegierung, Nanocomposite, Nanocompuesto, Oxyde de titane, Titanium oxide, Titanio óxido, Titanoxid, Propriété mécanique, Mechanical properties, Propiedad mecánica, Rupture, Ruptura, Bruch, Sensibilité vitesse déformation, Strain rate sensitivity, Sensibilidad velocidad deformación, Dehngeschwindigkeitsempfindlichkeit, Vitesse déformation, Strain rate, Velocidad deformación, and Verformungsgeschwindigkeit

Annealed and wrought AA5052 aluminum alloy was subjected to friction stir processing (FSP) without and with 3 vol pct TiO2 nanoparticles. Microstructural studies by electron backscattered diffraction and transmission electron microscopy showed the formation of an ultra-fine-grained structure with fine distribution of TiO2 nanoparticles in the metal matrix. Nanometric Al3Ti and MgO particles were also observed, revealing in-situ solid-state reactions between Al and Mg with TiO2. Tensile testing at different strain rates determined that FSP decreased the strain rate sensitivity and work hardening of annealed Al-Mg alloy without and with TiO2 nanoparticles, while opposite results were obtained for the wrought alloy. Fractographic studies exhibited that the presence of hard reinforcement particles changed the fracture mode from ductile rupture to ductile-brittle fracture. Notably, the failure mechanism was also altered from shear to tensile rupture as the strain rate increased. Consequently, the fracture surface contained hemispherical equiaxed dimples instead of parabolic ones.

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, Point fluage, Yield point, Límite fluencia(aceros), Préparation surface, Surface preparation, Preparación superficie, Oberflaechenvorbereitung, Traitement surface, Surface treatment, Tratamiento superficie, and Oberflaechenbehandlung

Nanoindentation was used to evaluate the effect of three surface preparation techniques—mechanical polishing, electropolishing, and ion polishing—on experimental measurements of incipient plasticity in commercially pure Ni 200. Surface preparation techniques are linked to defect densities, estimated with image quality (IQ) and kernel average misorientation (KAM) data obtained from electron backscatter diffraction patterns and the Taylor relation. Minimum yield pressures are insensitive to surface preparation, while mean yield pressure depends on dislocation density, and the maximum yield pressure is likely influenced by defects other than dislocations. KAM coupled with IQ may be a useful non-destructive parameter to relate surface defect density to the resulting changes in the spatial variability of incipient plasticity during a nanoindentation experiment. This analysis makes the assumption that geometrically necessary dislocation density is proportional to total dislocation density; in cases where this condition is not satisfied, the KAM analysis may not be valid.

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, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Condition opératoire, Operating conditions, Condición operatoria, Matériau composite, Composite material, Material compuesto, Verbundwerkstoff, Microstructure, Microestructura, Mikrogefuege, Multicouche, Multiple layer, Capa múltiple, Mehrfachschicht, Revêtement composite, Composite coating, Revestimiento compuesto, Texture, Textura, and Textur

A combination of accumulative roll bonding and rolling is used to fabricate bulk sheets of multilayer Cu-Nb bimetallic composites. Alterations in the processing sequence are made in comparison with prior studies in order to expand the processing window available for bimetallic multilayer composites. Cu-Nb composites with layer thicknesses ranging from 45 μm to 10 nm with accompanying total strains of 3.8 to 12.21 are characterized via neutron diffraction, electron back scatter diffraction, and transmission electron microscopy. These characterization methods provide microstructural information such as layer morphology and grain morphology as well as orientation information such as texture and interface plane normal distribution. The evolution of these microstructural characteristics is collected as a function of increasing strain. These results can provide guidance, inputs, and validation for multiscale predictive models that are being developed on materials with interfacially-driven properties. Finally, synthesis pathways are presented that allow the fabrication of nanoscale multilayer composites with predominant interfacial structures. These fabricated materials are ideal for exploring the relative importance between inter-phase interfacial density and atomic interfacial structure in determining material properties.

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, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Dépôt électrolytique, Electrodeposition, Depósito electrolítico, Elektroplattieren, Morphologie, Morphology, Morfología, Phosphate de calcium, Calcium phosphate, Calcio fosfato, Calciumphosphat, Procédé dépôt, Deposition process, Procedimiento revestimiento, Beschichtungsverfahren, Transformation phase, Phase transformation, Transformación fase, and Phasenumwandlung

The phase transformation and morphology of calcium phosphate prepared by the electrochemical deposition (ECD) process through alkali treatment and calcination have been characterized using X-ray diffraction (XRD), thermogravimetry and differential thermal analyses (TG/DTA), and scanning electron microscopy (SEM). At the ECD process, when the excess OH- was produced, the reaction of 10Ca2+ + 6PO3-4 + 2OH―→Ca10(PO4)6(OH)2 takes place on the Ti-6A1-4V and the HA is deposited. The XRD results reveal that the as-deposit was mostly composed of dicalcium phosphate dehydrate (Ca2H4P2O9; DCPD) and the minor phase of hydroxyapatite (Ca10(PO4)6(OH)2; HA). After NaOH treatment, all DCPD were converted to HA. Moreover, the content of HA phase increases with ECD potential. After being calcined at 673 K and 873 K (400 °C and 600 °C) for 4 hours, the phase of HA maintained the major phase for an alkali-treated deposited sample. After being calcined at 1073 K (800 °C) for 4 hours, some HA decomposed and caused the minor phases of β-tricalcium phosphate (β-Ca3(PO4)2; β-TCP), calcium pyrophosphate (Ca2P2O7; CPP), and calcium oxide (CaO) formation. The β-TCP becomes the major phase with residual HA and CaO after being calcined at 1273 K (1000 °C) for 4 hours. The crack forms due to the release of absorbed water from the interior to top surface of sample. For the as-alkali treatment samples, the microstructures were affected by ECD potentials; when the deposited samples after alkali treatment and calcined at 1073 K (800 °C) for 4 hours, the microstructure presents the need-like preforming HA (pre-HA) from the matrix of plate-like postforming HA (post-HA).

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, Assemblage et découpage thermique: aspects métallurgiques, Joining, thermal cutting: metallurgical aspects, Soudage, Welding, Acier bas carbone, Low carbon steel, Acero bajo carbono, Kohlenstoffarmer Stahl, Acier non allié, Carbon steel, Acero no aliado, Unlegierter Stahl, Assemblage soudé, Welded joint, Ensamblaje soldado, Schweissverbindung, Ecrouissage, Work hardening, Endurecimiento en frío, Soudage par points, Spot welding, Soldadura punto, Soudage résistance par points, Resistance spot welding, Soldadura por resistencia de puntos, Punktschweissen, Traitement surface, Surface treatment, Tratamiento superficie, and Oberflaechenbehandlung

Highly cold worked (HCW) low carbon steel sheets with cellular structure in the range of 200 to 300 nm are fabricated via constrained groove pressing process. Joining of the sheets is carried out by resistance spot welding process at different welding currents and times. Thereafter, failure behavior of these welded samples during tensile-shear test is investigated. Considered concepts include; failure load, fusion zone size, failure mode, ultimate shear stress, failure absorbed energy, and fracture surface. The results show that HCW low carbon steel spot welds have higher failure peak load with respect to the as-received one at different welding currents and times. Also, current limits for failure mode transition from interfacial to pullout or from pullout to tearing are reduced for HCW samples. Fusion zone size is the main geometrical factor which affects the failure load variations. Ultimate shear stress of spot welds is increased with decreasing the heat input and for HCW samples at a specific welding current and time, it is lower than that of the as-received ones. Before pullout mode, failure absorbed energy (FAE) for HCW low carbon steel spot welds is higher than that of the as-received one, but after failure mode transition, trend would be vice versa and FAE of the as-received spot welds is extremely higher (about 3 times). In addition, spot welds fracture surface (in interfacial failure mode) for HCW sample is more dimpled which indicates higher energy absorption than that of the as-received one.

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, Propriétés mécaniques. Rhéologie. Mécanique de la rupture. Tribologie, Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology, Acier, Steel, Acero, Dépôt physique phase vapeur, Physical vapor deposition, Deposición física fase vapor, Physikalisches Aufdampfen, Gradient concentration, Concentration gradient, Gradiente concentración, Magnétron, Magnetron, Magnetrón, Matériau composite, Composite material, Material compuesto, Verbundwerkstoff, Microstructure, Microestructura, Mikrogefuege, Propriété mécanique, Mechanical properties, Propiedad mecánica, Pulvérisation irradiation, Sputtering, Pulverización irradiación, Sputtern, Revêtement composite, Composite coating, Revestimiento compuesto, Traitement surface, Surface treatment, Tratamiento superficie, and Oberflaechenbehandlung

Structure and adhesion properties of TiAlCrNbN coatings were investigated. These coatings were deposited onto AISI H13 steel substrate using pulsed dc closed field unbalanced magnetron sputtering at different deposition parameters including duty cycle, bias voltage, and working pressure. The coatings have been characterized by X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. The TiAlCrNbN-graded composite coatings have a dense and columnar structure. The X-ray diffraction patterns of coatings exhibited predominantly c-TiAlCrN, h-NbN, and h-TiAIN reflections. Scratch resistance test showed that the highest adhesion strength was attained as 68 N at 2.5 μs duty time, 100 V bias voltages, and 3 × 10-3 Torr deposition parameters. The lowest adhesion strength was obtained as 55 N at 0.5 μs duty time, 50V bias voltage, and 2 × 10-3 Torr deposition parameters.

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, Durcissement, Hardening, Endurecimiento, Haerten, Microstructure, Microestructura, Mikrogefuege, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Zinc, and Zink

Press hardening is increasingly being used to produce ultra-high strength steel parts for passenger cars. Al-Si, Zn, and Zn-alloy coatings have been used to provide corrosion protection to press hardening steel grades. The use of coatings has drawbacks such as coating delamination or liquid metal-induced embrittlement. In the present work, the microstructural evolution of Al-Zn coating during press hardening was studied. The 55 wt pct Al-Zn coating can in principle provide both Al barrier protection and Zn cathodic protection to press hardened steel. During the heat treatment associated with the press hardening, the 55 wt pct Al-Zn alloy coating is converted to an intermetallic surface layer of Fe2Al5 and a FeAl intermetallic diffusion layer. The Zn is separated from both intermetallic compounds and accumulates at grain boundaries and at the surface. This Zn separation process is beneficial in terms of providing cathodic protection to Al-Zn coated press hardening steel.

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, Dépôt électrolytique, Electrodeposition, Depósito electrolítico, Elektroplattieren, Microstructure, Microestructura, Mikrogefuege, Recuit, Annealing, Recocido, Gluehen, Structure grain fin, Fine grain structure, Estructura grano fino, Feinkorngefuege, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Traitement thermique, Heat treatment, Tratamiento térmico, and Waermebehandlung

In situ neutron diffraction during annealing was performed for ultrafine-grained as-deposited and cold-rolled pure iron. Changes in the integrated intensity and full-width at half-maximum in the diffraction profiles during annealing were measured. EBSD measurements were performed before and after annealing to obtain microstructural change. Abnormal grain growth was clearly found at 673 K (400 °C) upon annealing; this observation corresponds to the hydrogen desorption behavior of the as-deposited specimen. The texture changes from {111}〈hkl〉 to {211}〈hkl〉 between 673 K and 873 K (400 °C and 600 °C) upon continuous heating. Such a texture change is postulated to decrease the Lankford value from 7.6 to 2.2. The 40 pct cold-rolled specimen exhibited a complicated textural evolution upon annealing, which was caused by the intrusion of recrystallization at deformation bands.

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, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Matériau composite, Composite material, Material compuesto, Verbundwerkstoff, Multicouche, Multiple layer, Capa múltiple, Mehrfachschicht, Revêtement composite, Composite coating, and Revestimiento compuesto

Multilayered steel composites consisting of alternating martensite and austenite layers and exhibiting a combination of high strength and ductility were successfully fabricated. To understand the microplasticity mechanisms responsible for such exceptional mechanical behavior, 3D X-ray microscopy with a submicron beam size was employed to probe the stress/strain distribution within the top two layers during incremental tensile loading. The 3D depth-dependent strain gradients were monitored in situ near the martensite/austenite interfaces as a function of the load level. It was observed that the strain gradients redistributed during loading. Specifically, large compressive strains developed in the top martensite layer transverse to the loading direction, while small tensile strains were found across the layer interface into the underneath austenite layer.

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, Propriétés mécaniques. Rhéologie. Mécanique de la rupture. Tribologie, Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology, Propriété mécanique, Mechanical properties, Propiedad mecánica, Transformation phase, Phase transformation, Transformación fase, Phasenumwandlung, Acier, Steel, Acero, Effet composition, Composition effect, Efecto composición, Konzentrationseinfluss, Elément alliage, Alloying element, Elemento aleación, Legierungselement, Mouillage, Wetting, Remojo, Oxydation, Oxidation, Oxidación, Plasticité, Plasticity, Plasticidad, Plastizitaet, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Transformation martensitique, Martensitic transformation, Transformación martensítica, Martensitische Umwandlung, Zingage immersion, Hot dip galvanizing, Galvanización con cinc sumergido, and Feuerverzinken

The influence of the addition of minor alloying elements on the selective oxidation and the reactive wetting of CMnSi transformation-induced plasticity (TRIP) steels was studied by means of galvanizing simulator tests. Five TRIP steels containing small alloying additions of Cr, Ni, Ti, Cu, and Sn were investigated. After intercritical annealing (IA) at 1093 K (820 °C) in a N2 + 5 pct H2 gas atmosphere with a dew point of 213 K (-60 °C), two types of oxides were formed on the strip surface: Mn-rich xMnO·SiO2 (x > 1.5) and Si-rich xMnO·SiO2 (x < 0.3) oxides. The addition of the minor alloying elements changed the morphology of the Si-rich oxides from a continuous film to discrete islands and this improved the wettability by molten Zn. The improved wetting effect of the minor alloying elements was attributed to an increased area fraction of the surface where the oxides were thinner, enabling a direct unhindered reaction between Fe and the Al in the liquid Zn and the formation of the inhibition layer during the hot dip galvanizing. The addition of a small amount of Sn is shown to significantly decrease the density of Zn-coating defects on CMnSi TRIP steels.

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 matériaux non métalliques, Nonmetallic coatings, Corrosion, Action des agents de corrosion, Corrosion environments, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Application, Aplicación, Anwendung, Corrosion électrochimique, Electrochemical corrosion, Corrosión electroquímica, Elektrochemische Korrosion, Mousse métallique, Metal foam, Espuma metálica, Metallschaum, Nitrure de titane, Titanium nitride, Titanio nitruro, Titannitrid, Revêtement non métallique, Non metal coating, Revestimiento no metálico, and Nichtmetallischer Ueberzug

Highly porous Ti-Cu alloy foams were produced by powder metallurgy method for implant applications. Ti-Cu alloys were prepared with 3, 5, 7, and 10 wt pct Cu contents in order to determine optimum Cu addition. Cu addition enhances sinterability, and the Ti-Cu compacts were sintered at lower temperatures and times than pure Ti. Specimens were coated with a TiN film to enhance wear and corrosion resistance. Sintered specimens were precipitation hardened (aged) in order to increase mechanical properties. Corrosion properties of foams were examined by electrochemical techniques, such as potentiodynamic polarization, cyclic polarization, Tafel extrapolation, linear polarization resistance, and open-circuit potential measurement. Effect of Cu content, TiN coating, pH, and fluoride content of artificial saliva on electrochemical corrosion behavior of specimens was investigated.

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, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Développement, Development, Desarrollo, Entwicklung, Matériau composite, Composite material, Material compuesto, Verbundwerkstoff, Multicouche, Multiple layer, Capa múltiple, Mehrfachschicht, Niobium, Niobio, Niob, Revêtement composite, Composite coating, Revestimiento compuesto, Texture, Textura, and Textur

Multilayered Ti/Al/Nb composites were produced by the accumulative roll bonding (ARB) process utilizing pure Ti, Al, and Nb element sheets. Up to four cycles of ARB were applied to the composites. The microstructure and texture evolution on the Nb phase were studied by X-ray diffraction (XRD), transmission electron microscopy, scanning electron microscopy, and electron backscattered diffraction. Nb and Ti layers necked and fractured as the number of ARB passes increased. After four ARB cycles, a nearly homogeneous distribution of Nb and Ti layers in Al matrix was achieved. As-received Nb sheet exhibited a fully lamellar structure and had a strong cold-rolling texture. After subjecting to ARB, slight grain refining was observed and the high-angle boundary fraction was increased. The intensity of the a-fiber was weakened, while that of the γ-fiber was strengthened during ARB. The texture evolution was attributed to partial recrystallization during the ARB process as a result of adiabatic heating.

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, 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, Propriété mécanique, Mechanical properties, Propiedad mecánica, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Alliage base titane, Titanium base alloys, Aluminium alliage, Aluminium alloy, Aluminio aleación, Aluminiumlegierung, Frottement, Friction, Frotamiento, Reibung, Microstructure, Microestructura, Mikrogefuege, Nanocomposite, Nanocompuesto, Revêtement composite, Composite coating, Revestimiento compuesto, Tribologie, Tribology, Tribología, Vanadium alliage, Vanadium alloy, Vanadio aleación, and Vanadiumlegierung

In this paper, we show that duplex surface treatment, combining oxygen diffusion hardening with the subsequent deposition of thick, low-friction nanocomposite nc-MeC/a-C coatings to improve the tribological properties of the Ti-6Al-4V alloy. We have synthesized, in a magnetron sputtering process, the nanocomposite nc-MeC/a-C coatings (where Me denotes W or Ti transition metal) consisting of two dissimilar materials (nanocrystallites of transition metal carbides MeC and an amorphous carbon matrix a-C). The nano and microstructure of the substrate material and coatings were examined with the use of scanning and transmission electron microscopy as well as by X-ray diffractometry. It was found that different carbide nanocrystals of the same transition metal were embedded in an amorphous carbon matrix of both coatings. The HRTEM analysis indicated that the volume fraction of tungsten carbides in the nc-WC/a-C coating was equal to 13 pct, whereas in the nc-TiC/a-C one the volume fraction of the titanium carbides was equal to just 3 pct. The tribological properties, hardness, and scratch resistance of the coatings were investigated as well. The coefficient of friction (COF) of the coatings during dry sliding against 6 mm diameter alumina ball reached very low value, 0.05, in comparison with an oxygen-hardened alloy, whose COF was equal to 0.8. This low-friction effect of the coatings has been attributed to the formation of a self-lubricating film in sliding contact. The coatings exhibited similar failure morphology in the scratch tests. Even though the hardness was rather low, the coatings exhibited a very good wear resistance during sliding friction. The wear rate of the nc-WC/a-C coating was equal to 0.08 × 10-6 mm3 N-1 m-1 and for the nc-TiC/a-C one it was 0.28 x 10-6 mm3 N-1 m-1.

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, Condition opératoire, Operating conditions, Condición operatoria, Dépôt immersion, Dip coating, Depósito inmersión, Tauchbeschichten, Grosseur grain, Grain size, Grosor grano, Korngroesse, Microstructure, Microestructura, Mikrogefuege, Revêtement, Coatings, Revestimiento, Ueberzug, Texture, Textura, Textur, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Zinc, and Zink

A galvanizing simulator was used to determine the effect of galvanizing bath antimony (Sb) content, substrate surface roughness, and cooling rate on the microstructural development of metallic zinc coatings. Substrate surface roughness was varied through the use of relatively rough hot-rolled and relatively smooth bright-rolled steels, cooling rates were varied from 0.1 to 10 K/s, and bulk bath Sb levels were varied from 0 to 0.1 wt pct. In general, it was found that increasing bath Sb content resulted in coatings with a larger grain size and strongly promoted the development of coatings with the close-packed {0002} basal plane parallel to the substrate surface. Increasing substrate surface roughness tended to decrease the coating grain size and promoted a more random coating crystallographic texture, except in the case of the highest Sb content bath (0.1 wt pct Sb), where substrate roughness had no significant effect on grain size except at higher cooling rates (10 K/s). Increased cooling rates tended to decrease the coating grain size and promote the {0002} basal orientation. Calculations showed that increasing the bath Sb content from 0 to 0.1 wt pct Sb increased the dendrite tip growth velocity from 0.06 to 0.11 cm/s by decreasing the solid-liquid interface surface energy from 0.77 to 0.45 J/m2. Increased dendrite tip velocity only partially explains the formation of larger zinc grains at higher Sb levels. It was also found that the classic nucleation theory cannot completely explain the present experimental observations, particularly the effect of increasing the bath Sb, where the classical theory predicts increased nucleation and a finer grain size. In this case, the poisoning theory of nucleation sites by segregated Sb may provide a partial explanation. However, any analysis is greatly hampered by the lack of fundamental thermodynamic information such as partition coefficients and surface energies and by a lack of fundamental structural studies. Overall, it was concluded that the fundamental mechanisms behind the microstructural development of solidified metallic zinc coatings have yet to be completely elucidated and require further investigation.

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, Corrosion, Action des agents de corrosion, Corrosion environments, Acier, Steel, Acero, Application, Aplicación, Anwendung, Chaudière, Boiler, Caldera, Dampfkessel, Corrosion haute température, High temperature corrosion, Corrosión alta temperatura, Hochtemperaturkorrosion, Haute température, High temperature, Alta temperatura, Hochtemperatur, Projection HVOF, HVOF spraying, Proyeccion HVOF, Projection à chaud, Hot spraying, Proyección en caliente, Spritzen, Revêtement, Coatings, Revestimiento, Ueberzug, Température, Temperature, Temperatura, Temperatur, Traitement surface, Surface treatment, Tratamiento superficie, and Oberflaechenbehandlung

To protect materials from surface degradations such as wear, corrosion, and thermal flux, a wide variety of materials can be deposited on the materials by several spraying processes. This paper examines and compares the microstructure and high-temperature corrosion of Ni-20Cr coatings deposited on T22 boiler steel by high velocity oxy-fuel (HVOF), detonation gun spray, and cold spraying techniques. The coatings' microstructural features were characterized by means of XRD and FE-SEM/EDS analyses. Based upon the results of mass gain, XRD, and FE-SEM/EDS analyses it may be concluded that the Ni-20Cr coating sprayed by all the three techniques was effective in reducing the corrosion rate of the steel. Among the three coatings, D-gun spray coating proved to be better than HVOF-spray and cold-spray coatings.

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 matériaux non métalliques, Nonmetallic coatings, Propriétés mécaniques. Rhéologie. Mécanique de la rupture. Tribologie, Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology, Propriété mécanique, Mechanical properties, Propiedad mecánica, Cermet, Cermetal, Dépôt projection, Spray coating, Depósito proyección, Spritzbeschichten, Frottement, Friction, Frotamiento, Reibung, Nanostructure, Nanoestructura, Plasma, Projection plasma, Plasma spraying, Proyección plasma, Plasmaspritzen, Projection à chaud, Hot spraying, Proyección en caliente, Spritzen, Revêtement non métallique, Non metal coating, Revestimiento no metálico, Nichtmetallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, and Oberflaechenbehandlung

Alumina dispersed FeCuAl-based nanostructured cermet coatings were deposited from nanostructured powders by atmospheric plasma spraying on low carbon steel substrates. Nanostructuring was retained in the deposited coatings which exhibit up to four distinctive phases as revealed by electron microscopy. In this study, the friction behavior of the distinctive phases at nano-normal load scale was investigated alongside their contribution to the overall friction behavior at macro-normal load scale. Friction behavior at nano-normal load scale was investigated by lateral force microscopy, whereas conventional tribometers were used for investigations at micro and macro-normal loads. It appeared that, the friction measured at nano-normal loads on individual phases is dictated by both composition and hardness of the corresponding phases, and thus influences the overall friction behavior of the coatings at macro-normal loads. Moreover, the coefficient of friction at macro-normal loads differs from the one at nano-normal loads, and deviates from Amonton's friction law.

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, Dépôt de matériaux non métalliques, Nonmetallic coatings, Courant pulsé, Pulsed current, Corriente pulsatoria, Pulsierender Strom, Dépôt électrolytique, Electrodeposition, Depósito electrolítico, Elektroplattieren, Morphologie, Morphology, Morfología, Nitrure de titane, Titanium nitride, Titanio nitruro, Titannitrid, 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, and Oberflaechenbehandlung

Pure Sn coatings are prepared by pulse current (PC) electrodeposition using aqueous acidic sulfate plating bath. The effects of various electroplating parameters such as current density, additive concentration, duty cycle, frequency, pH, bath temperature, and stirring rate (bath rotation) on the evolution of surface morphology of the coatings have been studied. The as-deposited coatings are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and surface profilometry. It is found that the current density, additive concentration, duty cycle, frequency, and pH have a major influence while temperature and stirring rate of the bath have a minor effect on the grain-size distribution. The mechanism involved in the morphology evolution and grain-size distribution due to the varying electroplating parameters has also been discussed.

Crystallography, Cristallographie cristallogenèse, Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, 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 dépôt de films et de revêtements; croissance de films et épitaxie, Methods of deposition of films and coatings; film growth and epitaxy, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Généralités, General, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Couche mince, Thin film, Capa fina, Duennschicht, Dopage, Doping, Dopen, Microstructure, Microestructura, Mikrogefuege, Procédé sol gel, Sol gel process, Procedimiento sol gel, Propriété optique, Optical properties, Propiedad óptica, Optische Eigenschaft, Revêtement, Coatings, Revestimiento, Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, and Oberflaechenbehandlung

In our study, undoped and lead (Pb)-doped ZnO thin films were deposited by sol-gel spincoating technique and the structural, morphological, and optical properties of the films were investigated as a function of Pb doping which was changed from 0 to 4 at. pct with 1 at. pct step. The XRD results exhibited that the films had a hexagonal wurtzite structure with (002) preferential orientation in all dopant ratios. The grain size values of Pb-doped films were lower than that of undoped ZnO, but the increase in strain and dislocation density values were observed with Pb doping. Detailed optical analysis showed that the average transmittance of all films varied between about 90 and 99 pct and the absorption edge of undoped ZnO film shifted from longer wavelength to short wavelengths (blue shift) with Pb doping. The optical band gap and Urbach energy values of undoped ZnO increased from 3.283 eV and 63 meV to 3.331 eV and 88 meV with increasing Pb doping ratio. But steepness parameter values showed reversely variation with increasing Pb doping. The AFM images expressed that the films had homogenous nanoparticle distribution on the surface and particle size of ZnO decreased with Pb doping ratio. These results suggested that undoped and Pb-doped ZnO thin films could be used in many technological areas.