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Geology, Géologie, Mechanics acoustics, Mécanique et acoustique, Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Electronique, Electronics, Electronique des semiconducteurs. Microélectronique. Optoélectronique. Dispositifs à l'état solide, Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices, Fabrication microélectronique (technologie des matériaux et des surfaces), Microelectronic fabrication (materials and surfaces technology), Metaux. Metallurgie, Metals. Metallurgy, Assemblage et découpage thermique: aspects métallurgiques, Joining, thermal cutting: metallurgical aspects, Brasage, Brazing. Soldering, Aimantation, Magnetization, Imanación, Magnetisieren, Argent alliage, Silver alloy, Plata aleación, Silberlegierung, Brasage avec refusion, Reflow soldering, Soldeo con refusión, Aufschmelzloeten, Calorimétrie différentielle balayage, Differential scanning calorimetry, Análisis calorimétrico barrido exploración, Differentialrasterkalorimetrie, Cobalt alliage, Cobalt alloy, Cobalto aleación, Cobaltlegierung, Cuivre alliage, Copper alloy, Cobre aleación, Kupferlegierung, Effet champ magnétique, Magnetic field effect, Efecto campo magnético, Magnetischer Feldeffekt, Etain alliage, Tin alloy, Estaño aleación, Zinnlegierung, Fabrication microélectronique, Microelectronic fabrication, Fabricación microeléctrica, Fer alliage, Iron alloy, Hierro aleación, Eisenlegierung, Fiabilité, Reliability, Fiabilidad, Zuverlaessigkeit, Matériau composite, Composite material, Material compuesto, Verbundwerkstoff, Métal transition alliage, Transition metal alloy, Metal transición aleación, Uebergangsmetallegierung, Nanomatériau magnétique, Magnetic nanomaterial, Nanomaterial magnético, Nanoparticule, Nanoparticle, Nanopartícula, Packaging électronique, Electronic packaging, Packaging electrónico, Particule magnétique, Magnetic particles, Perte magnétique, Iron loss, Pérdida magnética, Magnetischer Verlust, Propriété thermomécanique, Thermomechanical properties, Propriedad termomecánica, Brasure sans plomb, and Lead free solder

Sn-Ag-Cu (SAC) alloys are regarded as the most promising alternative for traditional Pb-Sn solders used in electronic packaging applications. However, the higher reflow temperature requirement, possible intermetallic formation, and reliability issues of SAC alloys generate several key challenges for successful adoption of Pb-free solder for next generation electronic packaging needs. Localized heating in interconnects can alleviate thermal stresses by preventing subjection of entire package to the higher reflow temperatures associated with the SAC solders. It had been demonstrated that SAC solder-FeCo magnetic nanoparticles (MNPs) composite paste can be reflowed locally with AC magnetic fields, enabling interconnect formation in area array packages while minimizing eddy current heating in the printed circuit board. Solder/magnetic nanocomposite pastes with varying MNP concentration were reflowed using AC magnetic fields. Differential scanning calorimetry results show a reduced undercooling of the composite pastes with the addition of MNPs. TEM results show that the FeCo MNPs are distributed in Sn matrix of the reflowed solder composites. Optical and SEM micrographs show a decrease in Sn dendrite regions as well as smaller and more homogeneous dispersed Ag3Sn with the addition of MNPs. The MNPs promote Sn solidification by providing more heterogeneous nucleation sites at relatively low undercoolings. The mechanical properties were measured by nanoindentation. The modulus, hardness, and creep resistance, increase with the MNP concentration. The enhanced mechanical properties are attributed to grain boundary and dispersion strengthening. The reflow of solder composites have been modeled based on eddy current power loss in the substrate and magnetic power losses in the solder bumps. Induction reflow of pure solder bumps (<300 μm) in an area array package using 500 Oe magnetic field at 300 kHz requires excessive eddy current power loss in the substrate, resulting in extreme temperatures that lead to blistering and delamination of the substrate. Solder-MNP composites with modest MNP loading showed temperature increases sufficient to achieve solder reflow when subjected to the same AC magnetic fields. Thermomechanical behavior of a solder joint was also modeled under cyclic temperature variations. The stress and strain are highly localized at the interface between solder and substrate. Plastic work accumulated per cycle can be used for lifetime prediction. In this article we review lead-containing and lead-free solder systems, and the electronic packaging technologies pertinent to soldering process. Recent research on the effects of MNPs on localized heating, microstructure evolution, mechanical properties, and thermomechanical reliability are summarized.

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.

Mechanical engineering, Génie mécanique, 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, Propriétés mécaniques. Rhéologie. Mécanique de la rupture. Tribologie, Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology, Fatigue, Charge variable, Variable load, Carga variable, Ungleichmaessige Beanspruchung, Contrainte seuil, Threshold stress, Tension umbral, Fatigue, Fatiga, Ermuedung, Fissure courte, Short crack, Fisura corta, Propriété mécanique, Mechanical properties, Propiedad mecánica, Non-propagating small cracks, Threshold stress intensities, Ultrasonic fatigue, Variable amplitude loading, and Very high cycle fatigue (VHCF)

Ever since high-strength steels were found to fail below the traditional fatigue limit when loaded with more than 108 cycles, the investigation of metals' and alloys' very high cycle fatigue properties has received increased attention. A lot of research was invested in developing methods and machinery to reduce testing times. This overview outlines the principles and testing procedures of very high cycle fatigue tests and reports findings in the areas of crack formation, non-propagating small cracks, long crack propagation and thresholds. Furthermore, superimposed and variable amplitude loading as well as frequency effects are reported.

Mechanical engineering, Génie mécanique, 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, Propriétés mécaniques. Rhéologie. Mécanique de la rupture. Tribologie, Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology, Fatigue, Alliage base aluminium, Aluminium base alloys, Charge variable, Variable load, Carga variable, Ungleichmaessige Beanspruchung, Fatigue, Fatiga, Ermuedung, Propriété mécanique, Mechanical properties, Propiedad mecánica, 2024 Aluminium alloy, Damage accumulation, Ultrasonic fatigue, Variable amplitude loading, and Very high cycle fatigue

Ultrasonic fatigue tests with variable amplitude are performed for the first time at positive load ratios. The method utilising ultrasonic equipment, a servo-hydraulic or electromechanical load frame and computer control is described. Aluminium alloy 2024-T351 is tested at approximately 20 kHz with variable amplitude in the high cycle fatigue (HCF) and very high cycle fatigue (VHCF) regime at load ratios R = -1, R = 0.1 and R = 0.5. Constant amplitude data are available and are used for Miner damage accumulation calculations. For load ratio R = -1, the mean damage sum decreases from 0.5 to 0.3 when lifetimes increase from the HCF regime to 109 cycles, and increases at higher numbers of cycles. For load ratio R = 0.1, the mean damage sum decreases from 1.1 to 0.2 when lifetimes increase from HCF to VHCF. At load ratio R = 0.5, the mean damage sum is approximately 0.1 in the VHCF regime. Cracks leading to VHCF failures start at broken constituent particles, probably Al7Cu2(Fe,Mn), or at agglomerations of fractured particles. Crack initiation occurs at the surface or less frequently in the interior.

Mechanical engineering, Génie mécanique, 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, Propriétés mécaniques. Rhéologie. Mécanique de la rupture. Tribologie, Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology, Fatigue, Acier cémenté, Case hardened steel, Acero cementado, Amorçage fissure, Crack initiation, Iniciación grieta, Risseinleitung, Fatigue, Fatiga, Ermuedung, Microstructure, Microestructura, Mikrogefuege, Propriété mécanique, Mechanical properties, Propiedad mecánica, Case-hardened steel, Competing sites of crack initiation, Kitagawa diagram, and Very high cycle fatigue (VHCF)

In this investigation notched and fracture mechanics specimens were machined from the steel SAE 5120 (DIN EN 20MnCr5) in two cleanliness conditions. The first material is used for high-performance components and is nearly free of oxides. The second material is standard steel and used for common requests in the field of drive engineering containing non-metallic inclusions in a dimension that is state of the art in steel making. The notched specimens were case-hardened in two different ways. Afterwards, the surfaces were ground and therefore showed compressive residual stresses. Uniaxial VHCF tests were performed up to 200 million cycles under the stress ratios R = ―1 and R = 0 using two resonant pulse systems. For this purpose the geometries of the specimens had been optimised so that the achieved test frequency was 190 Hz. Fatigue failure is possible at all applied numbers of cycles meaning that there is no real fatigue limit in this region. Fatigue crack initiation took place from different origins and at different sites. Different analyses are shown for interpretating the type of fatigue crack initiation and its site in the specimen. The fracture mechanics specimens were blank hardened in order to have the core properties of the notched specimens. Crack propagation was measured in the near-threshold region. An extended Kitagawa diagram is shown to demonstrate the influence of stress amplitude and flaw size on the failure probability.

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.

Mechanical engineering, Génie mécanique, 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, Propriétés mécaniques. Rhéologie. Mécanique de la rupture. Tribologie, Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology, Fatigue, Acier austénito ferritique, Austenitic ferritic steel, Acero ferrítico austenítico, Austenitisch ferritischer Stahl, Acier double phase, Dual phase steel, Acero doble fase, Dualphasenstahl, Acier inoxydable duplex, Duplex stainless steel, Acero inoxidable duplex, Acier inoxydable, Stainless steel, Acero inoxidable, Nichtrostender Stahl, Contrainte thermomécanique, Thermomechanical stress, Tensión termomecánica, Décomposition spinodale, Spinodal decomposition, Decomposición espinodal, Spinodale Entmischung, Fatigue, Fatiga, Ermuedung, Point Curie, Curie temperature, Punto Curie, Curie Temperatur, Propriété mécanique, Mechanical properties, Propiedad mecánica, Température, Temperature, Temperatura, Temperatur, and Thermo mechanical fatigue

The thermo mechanical fatigue behaviour of a ferritic-austenitic duplex stainless steel has been investigated in a temperature range of 350-600 °C. The Curie temperature (TCURIE) was determined by an abrupt increase of the power of the inductive heating device and a small control deviation of the temperature. Thus, according to Tavares et al. [1] the evolution of the spinodal decomposition in the DSS was characterised by the shift of the Curie temperature for each test. The results are compared with ageing and annealing experiments in combination with tensile tests at room temperature. In addition, microstructure observations were performed in a field-emission scanning electron microscope.

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.

Mechanical engineering, Génie mécanique, 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, 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, Fatigue, Techniques de l'ingénieur appliqués à la métallurgie. Applications. Divers, Engineering techniques in metallurgy. Applications. Other aspects, Applications, Industrie automobile, Automotive engineering, Application, Aplicación, Anwendung, Châssis véhicule, Vehicle chassis, Chasis vehículo, Fahrgestell, Conception, Design, Diseño, Gestaltung, Corrosion sel, Salt corrosion, Corrosión sal, Salzkorrosion, Durée vie, Lifetime, Tiempo vida, Lebensdauer, Fatigue, Fatiga, Ermuedung, Industrie automobile, Automobile industry, Industria automóvil, Autoindustrie, Propriété mécanique, Mechanical properties, Propiedad mecánica, Forged aluminium, Special events, Spectrum loading, and Tension strut

The structural durability design of a tension strut of forged aluminium (EN AW 6082 T6), which is a safety component of the automotive chassis, is described. The first step of the structural durability design is the knowledge of the mechanical and environmental loadings. The mechanical loadings are the spectrum loading for the designated normal driving conditions and unintended special event loadings by e.g. braking over road bumps, which are introduced into the component through the wheels. The local stresses imposed on the component are also influenced by kinematics, stiffness, axle mass, dampers, bearings, bump geometry, etc. The environmental loading is the corrosion caused, in winter-time, by salty water on the roads. For design according to the local stress concept, the knowledge of Woehler-curves without and with salt corrosion effects is necessary. On this basis, cumulative fatigue under spectrum loading, which also comprises the special events mentioned, is assessed for a standard configuration and for an optimised one. The numerical results are verified by experimental proofs on the component in the laboratory and on the proving ground as well as by field tests with vehicles.

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.

Mechanical engineering, Génie mécanique, 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, Propriétés mécaniques. Rhéologie. Mécanique de la rupture. Tribologie, Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology, Fatigue, Anisotropie, Anisotropy, Anisotropía, Fatigue, Fatiga, Ermuedung, Glissement, Slip, Deslizamiento, Gleiten, Joint grain, Grain boundary, Limite grano, Korngrenze, Microstructure, Microestructura, Mikrogefuege, Modélisation, Modeling, Modelización, Méthode élément fini, Finite element method, Método elemento finito, Finite Element Methode, Propagation fissure, Crack propagation, Propagación fisura, Rissausbreitung, Propriété mécanique, Mechanical properties, Propiedad mecánica, Prédiction, Prediction, Predicción, Système glissement, Slip system, Sistema deslizamiento, Gleitsystem, Crack path, and Extended finite element

This study develops a new method for the analysis of fatigue crack growth at micro-structural scale. Proposed model was constructed based on material anisotropic properties and crystallographic planes. In this research, it has been attempted to suggest an accurate and precise criterion for the prediction of crack growth path at micro-structural scales by the study of various criteria for crack growth. For this purpose, considering fracture energy for trans-granular and inter-granular fracture as well as dominant slip planes, a criterion was proposed to predict crack growth. In the current research, fatigue tests were performed on two different alloys and the real path of the crack growth was obtained. Next, by the simulation of tested pieces through finite element software (ABAQUS) and using extended finite element method, various criteria to predict crack growth path were studied. The microstructures of both specimens tested in considered areas were modelled with an anisotropic behaviour and their crystal orientations were gained using electron-back-scattering-diffraction-pattern (EBSP) method. The results suggest the accuracy and precision of proposed criterion with minor error in single-phase alloys and major difference in two-phase alloys.

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.