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Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt projection, Spray coating, Depósito proyección, Spritzbeschichten, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Modélisation, Modeling, Modelización, Métaux dissemblables, Dissimilar metals, Metales desemejantes, Verschiedenartige Metalle, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Bonding, Cold spray, Impact, Modelling, and SPH

In this study, the critical, maximum and optimum velocity of a single cold sprayed (CS) particle is estimated using the smoothed particle hydrodynamics (SPH) method by evaluating the impact shape coefficient of restitution, as well as the rebound and deposit energy ratio. The contact surfaces of the particle and the substrate are modelled as intersurface forces using the Dugdale-Barenblatt cohesive zone model. The application of SPH allows the simulation of the CS process without the use of mesh, thereby avoiding the disadvantages of the traditional numerical method in handling large deformations and tracing moving interfaces. The impact of CS particles is simulated using various powder and substrate materials. The influence of the materials on the optimum velocity and the coating quality is discussed. The reliability of the model is verified with CS experiments.

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 aluminium, Aluminium base alloys, Alliage ternaire, Ternary alloy, Aleación ternaria, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Microstructure, Microestructura, Mikrogefuege, Modélisation, Modeling, and Modelización

A numerical formulation of solidification model which can predict the microsegregation and microstructural features for multicomponent alloys is presented. The model incorporates the kinetic features during solidification such as solute back diffusion, dendrite tip undercooling, and secondary arm coarsening. The model is dynamically linked to thermodynamic library for accurate input of thermodynamic data. The modeling results are tested against the directional solidification experiments for Mg-Al-Zn alloys. The experiments were conducted in the cooling rate range of 0.13 to 2.33 K/s and microstructural features such as secondary arm spacing, primary dendrite arm spacing, second phase fraction, and microsegregation were compared with the modeling results. Based on the model and the experimental data, a solidification map was built in order to provide guidelines for as-cast microstructural features of Mg-Al-Zn alloys in a wide range of solidification conditions.

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

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

Chemical industry parachemical industry, Industrie chimique et parachimique, Mechanics acoustics, Mécanique et acoustique, Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, 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, Alumine, Alumina, Alúmina, Tonerde, Aluminium alliage, Aluminium alloy, Aluminio aleación, Aluminiumlegierung, Coefficient frottement, Friction coefficient, Coeficiente roce, Reibungskoefficient, Composite hybride, Hybrid composite, Compuesto híbrido, Composite matrice métallique, Metal matrix composite, Compuesto matriz metalico, Céramique oxyde, Oxide ceramics, Cerámica óxido, Oxidkeramik, Dureté, Hardness, Dureza, Haerte, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Graphite, Grafito, Graphit, Matériau composite, Composite material, Material compuesto, Verbundwerkstoff, Métal renforcé dispersion, Dispersion strengthened metal, Metal reforzado dispersión, Dispersionsgehaertetes Metall, Propriété mécanique, Mechanical properties, Propiedad mecánica, Résistance compression, Compressive strength, Resistencia compresión, Druckfestigkeit, Résistance flexion, Bending strength, Resistencia flexión, Biegefestigkeit, Résistance traction, Tensile strength, Resistencia tracción, Zugfestigkeit, Résistance usure, Wear resistance, Resistencia al desgaste, Verschleissfestigkeit, Tribologie, Tribology, Tribología, Usure glissement, Sliding wear, Desgaste deslizamiento, Gleitverschleiss, A. Metal-matrix composites (MMCs), A. Particle-reinforcement, B. Wear, and E. Casting

This work investigated the influence of graphite on the wear behavior of Al 7075/Al2O3/5 wt.% graphite hybrid composite. The investigation reveals the effectiveness of incorporation of graphite in the composite for gaining wear reduction. The Al 7075 (aluminium alloy 7075) reinforced with Al2O3―graphite were investigated. The composites were fabricated using liquid metallurgy route. Ceramic particles along with solid lubricating materials were incorporated into aluminium alloy matrix to accomplish reduction in both wear resistance and coefficient of friction. The Al 7075/Al2O3/graphite hybrid composite was prepared with 5 wt.% graphite particles addition and 2, 4, 6 and 8 wt.% of Al2O3. The hardness, tensile strength, flexural strength and compression strength of the Al 7075―Al2O3―graphite hybrid composites are found to be increased by increased weight percentage of ceramic phase. The wear properties of the hybrid composites containing graphite exhibited the superior wear-resistance properties.

Chemical industry parachemical industry, Industrie chimique et parachimique, Mechanics acoustics, Mécanique et acoustique, Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Science des matériaux, Materials science, Matériaux particuliers, Specific materials, Autres matériaux, Other materials, 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, Autres propriétés mécaniques, Other mechanical properties, Aluminium alliage, Aluminium alloy, Aluminio aleación, Aluminiumlegierung, Critère rupture, Fracture criterion, Criterio ruptura, Epaisseur, Thickness, Espesor, Dicke, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Limite élasticité, Yield strength, Límite elasticidad, Streckgrenze, Mode rupture, Fracture mode, Modo ruptura, Modèle mécanique, Mechanical model, Modelo mecánico, Modélisation, Modeling, Modelización, Mousse métallique, Metal foam, Espuma metálica, Metallschaum, Panneau sandwich, Sandwich board, Panel sandwich, Propriété mécanique, Mechanical properties, Propiedad mecánica, Résistance flexion, Bending strength, Resistencia flexión, Biegefestigkeit, Simulation numérique, Numerical simulation, Simulación numérica, A. Foams, A. Laminates, B. Mechanical properties, and D. Mechanical testing

The response of aluminium sandwich panels comprising thin foam cores and thin face sheets of low and high yield strength was investigated under three-point bending load. The effect of skin strength, bending span and core thickness on the failure modes and loads was investigated. While the lower strength face sheet is associated with lower failure loads, that decrease is not proportional to the yield strength due to the additional failure mode of face yielding. Theoretical models enabled prediction of the failure loads and elucidated the contribution of each failure mode. Failure maps were subsequently constructed which can be used for the design of foam-cored sandwich panels with very thin face sheets.

Chemical industry parachemical industry, Industrie chimique et parachimique, Mechanics acoustics, Mécanique et acoustique, Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Metaux. Metallurgie, Metals. Metallurgy, Corrosion, Protection contre la corrosion, Corrosion prevention, Acier, Steel, Acero, Aniline dérivé polymère, Aniline derivative polymer, Anilina derivado polímero, Argile organique, Organic clay, Arcilla orgánica, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Kaolinite, Caolinita, Matériau composite, Composite material, Material compuesto, Verbundwerkstoff, Morphologie, Morphology, Morfología, Méthyle sulfoxyde, Methyl sulfoxide, Sulfóxido de dimetilo, Nanocomposite, Nanocompuesto, Polymère aromatique, Aromatic polymer, Polímero aromático, Polymère conducteur, Conducting polymers, Polymérisation oxydante, Oxidative polymerization, Polimerizacion oxidante, Propriété thermique, Thermal properties, Propiedad térmica, Thermische Eigenschaft, Propriété électrochimique, Electrochemical properties, Propiedad electroquímica, Elektrochemische Eigenschaft, Préparation, Preparation, Preparación, Vorbereitung, Revêtement anticorrosion, Corrosion protective coatings, Résistance corrosion, Corrosion resistance, Resistencia corrosión, Korrosionsbestaendigkeit, Stabilité thermique, Thermal stability, Estabilidad térmica, Thermische Stabilitaet, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Aniline(2,3-diméthyl) polymère, Polymérisation intercalative, A. Nanoclays, A. Polymers, B. Corrosion, and B. Thermal properties

Poly(2,3-dimethylaniline)/kaolinite nanocomposites (P(2,3-DMA)/K2) were prepared by in situ intercalative polymerization in the presence of organically modified kaolinite, based on the intercalation modification of crude kaolinite with dimethylsulfoxide (DMSO) and methanol system. Intercalation extent of kaolinite, Structure, Morphology and Thermal stability of the nanocomposites were characterized by XRD, FTIR, SEM and TGA-DTA, respectively. The electrochemical behavior of the as-prepared nanocomposites was evaluated by open circuit potential (OCP), tafel polarization curves (TAF) and impedance spectroscopy (EIS) in 3.5 wt% NaCl aqueous solution. Experimental results indicated that the clay layers of kaolinite in P(2,3-DMA)/K2 were well intercalated and exfoliated, and the P(2,3-DMA)/K2 had a more higher thermal stability and anticorrosion properties relative to the bulk poly(2,3-dimethylaniline) (P(2,3-DMA)) and the P(2,3-DMA)/crude kaolinite composites (P(2,3-DMA)/K0).

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, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Joint grain, Grain boundary, Limite grano, Korngrenze, Microstructure, Microestructura, Mikrogefuege, Migration joint grain, Grain boundary migration, Migración limite grano, Korngrenzenwanderung, Grain boundary energy, Grain rotation, and Inclination

The motion and faceting behavior of low-angle 〈100〉 tilt and mixed tilt-twist boundaries was investigated. The experiments were conducted on high-purity (99.999%) aluminum bicrystals by utilizing an in situ technique for the observation and continuous recording of boundary migration. In contrast to pure tilt boundaries, the mixed boundaries were found to readily assume a curved shape and steadily move under the capillary driving force. This behavior is associated with the inclination dependence of boundary energy, which was determined for tilt and mixed boundaries by molecular statics simulations. The shape evolution and shrinkage kinetics of cylindrical grains with different tilt and mixed boundaries were studied by molecular dynamics simulations. The mobility of low-angle (100) boundaries with misorientation angle >10°, obtained by both the experiments and simulations, does not differ from that of the high-angle boundaries, but decreases essentially with the further decrease of misorientation. The shape evolution of the embedded grains was found to relate directly to results of the energy computations. Further simulation results revealed that the shrinkage of grains with pure tilt boundaries is accompanied by grain rotation. In contrast, grains with the tilt-twist boundaries composed of dislocations with the mixed edge-screw character do not rotate as they shrink.

Chemical industry parachemical industry, Industrie chimique et parachimique, Mechanics acoustics, Mécanique et acoustique, Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Métallurgie des poudres. Matériaux composites, Powder metallurgy. Composite materials, Métaux renforcés par dispersion, Dispersion hardening metals, Agitation mécanique, Stirring, Agitación mecánica, Aluminium alliage, Aluminium alloy, Aluminio aleación, Aluminiumlegierung, Composite matrice métallique, Metal matrix composite, Compuesto matriz metalico, Coulée en moule, Casting, Colada molde, Giessen, Dureté, Hardness, Dureza, Haerte, Effet température, Temperature effect, Efecto temperatura, Temperatureinfluss, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Matériau composite, Composite material, Material compuesto, Verbundwerkstoff, Microstructure, Microestructura, Mikrogefuege, Mouillabilité, Wettability, Remojabilidad, Benetzbarkeit, Métal renforcé dispersion, Dispersion strengthened metal, Metal reforzado dispersión, Dispersionsgehaertetes Metall, Métallurgie poudre, Powder metallurgy, Metalurgia polvo, Pulvermetallurgie, Nanocomposite, Nanocompuesto, Optimisation, Optimization, Optimización, Optimierung, Oxyde de magnésium, Magnesium oxide, Magnesio óxido, Magnesiumoxid, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété surface, Surface properties, Propiedad superficie, Oberflaecheneigenschaft, Résistance compression, Compressive strength, Resistencia compresión, Druckfestigkeit, A. Metal―matrix composites (MMCs), A. Particle-reinforcement, B. Mechanical properties, and E. Casting

In the present work, Al―nano MgO composites using A356 aluminum alloy and MgO nanoparticles (1.5, 2.5, and 5 vol.%) have been fabricated via stir casting and powder metallurgy (PM) methods. Different processing temperatures of 800, 850, and 950 °C for stir casting and 575, 600, and 625 °C for powder metallurgy were considered. Powder metallurgy samples showed more porosity portions compare to the casting samples which results in higher density values of casting composites (close to the theoretical density) compare to the sintering samples. Introduction of MgO nanoparticles to the Al matrix caused increasing of the hardness values which was more considerable in casting samples. The highest hardness value for casting and sintering samples have been obtained at 850 and 625 °C respectively, in 5 vol.% of MgO. Compressive strength values of casting composites were higher than sintered samples which were majorly due to the more homogeneity of Al matrix, less porosity portions, and better wettability of MgO nanoparticles in casting method. The highest compressive strength values for casting and sintered composites have been obtained at 850 and 625 °C, respectively. Scanning electron microscopy images showed higher porosity portions in sintered composites and more agglomeration and aggregation of MgO nanoparticles in casting samples which was due to the fundamental difference of two methods. Generally, the optimum processing temperatures to achieve better mechanical properties were 625 and 850 °C for powder metallurgy and stir-casting, respectively. Moreover, casting method represented more homogeneous data and higher values of mechanical properties compare to the powder metallurgy method.

Crystallography, Cristallographie cristallogenèse, Chemical industry parachemical industry, Industrie chimique et parachimique, Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Equations d'état, équilibres de phases et transformations de phases, Equations of state, phase equilibria, and phase transitions, Solubilité, ségrégation, mélanges et séparation de phases, Solubility, segregation, and mixing; phase separation, 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, Rupture, Fractures, Addition silicium, Silicon addition, Adición silicio, Siliciumzusatz, Composition chimique, Chemical composition, Composición química, Chemische Zusammensetzung, Ductilité, Ductility, Ductilidad, Verformungsfaehigkeit, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Eutectique, Eutectic, Eutéctico, Eutektikum, Fer, Iron, Hierro, Eisen, Graphite, Grafito, Graphit, Microstructure, Microestructura, Mikrogefuege, Mode rupture, Fracture mode, Modo ruptura, Propagation fissure, Crack propagation, Propagación fisura, Rissausbreitung, Propriété mécanique, Mechanical properties, Propiedad mecánica, Rupture, Ruptura, Bruch, Résistance mécanique, Strength, Resistencia mecánica, Festigkeit, Silicium, Silicon, Silicio, Ségrégation, Segregation, Segregación, Seigerung, Substrat silicium, Segregations and rupture surfaces, and Spheroidal graphite cast iron

An experimental study of mechanical properties and microstructural analysis was carried out on different compositions of ferritic spheroidal graphite cast iron. The influence of silicon on the ductility and strength of the material was noticed. The observation of microstructure and failure modes allowed us to explain the important role of chemical composition on the initiation and propagation of cracks. The high silicon segregation between the graphite nodules and the joints of eutectic cells decreases the mechanical material resistance. A metallurgical development was indispensable and necessary to ensure characteristics conformed to the industrial requirements.

Crystallography, Cristallographie cristallogenèse, Chemical industry parachemical industry, Industrie chimique et parachimique, Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Structure des liquides et des solides; cristallographie, Structure of solids and liquids; crystallography, Défauts et impuretés dans les cristaux; microstructure, Defects and impurities in crystals; microstructure, Défauts d'empilement et autres défauts plans ou étendus, Stacking faults and other planar or extended defects, Propriétés de transport (non électroniques), Transport properties of condensed matter (nonelectronic), Diffusion dans les solides, Diffusion in solids, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Science des matériaux, Materials science, Traitement des matériaux et son effet sur la microstructure et les propriétés, Treatment of materials and its effects on microstructure and properties, Elasticité et anélasticité, Elasticity and anelasticity, 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, Elasticité. Plasticité, Elasticity. Plasticity, Compression uniaxiale, Uniaxial compression, Compresión uniaxial, Diffraction électron rétrodiffusé, EBSD, Diffractión electrón retrodifusa, Diffusion(transport), Diffusion, Dislocation, Dislocación, Versetzung, Défaut cristallin, Crystal defect, Defecto cristalino, Défaut empilement, Stacking fault, Defecto apilado, Stapelfehler, Epaisseur, Thickness, Espesor, Dicke, Essai traction compression, Tension compression fatigue test, Ensayo tracción compresión, Zug Druck Dauerversuch, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Extrusion, Extrusión, Glissement, Slip, Deslizamiento, Gleiten, Maclage, Twinning, Chocleo, Zwillingsbildung, Macle mécanique, Mechanical twin, Macla mecánica, Verformungszwilling, Magnésium alliage, Magnesium alloy, Magnesio aleación, Magnesiumlegierung, Microscopie électronique transmission, Transmission electron microscopy, Microscopía electrónica transmisión, Transmissionselektronenmikroskopie, Propriété traction, Tensile property, Propiedad tracción, Zugeigenschaft, 6172L, 6172N, 8140J, Deformation twinning, and HRTEM

This study presents experimental evidence for the sequence of activation and the evolution of primary tension (TTW), secondary compression (CTW) and tertiary double twinning (DTW) in an extruded Mg-4 wt%Li alloy during uniaxial compression by means of in-situ and ex-situ EBSD and (HR-)TEM. In-situ EBSD analysis reveals that the secondary CTWs propagate very slowly, while the tertiary DTWs propagate faster once nucleated. Thereby, when DTW-ing overtakes the CTW, CTW boundary migration stops, indicating that the thickness of the CTW is limited by the onset of internal DTW-ing. This finding confirms some prior proposals based on post-mortem analyses. High-resolution (HR-)TEM analysis of a -18% compressed sample reveals significant basal slip activity and a high amount of basal stacking faults within the primary TTW as well as within the secondary CTW. Additionally, the HR-TEM analysis showed a large amount of basal dislocations within the area of the CTW-DTW transition. These findings give strong experimental evidence that the observed predominance of type 1 DTW-ing is related to the dissociation of extended basal dislocations.

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, Composé intermétallique, Intermetallic compound, Compuesto intermetálico, Intermetallische Verbindung, Diffusion, Difusión, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Modélisation, Modeling, Modelización, Gold, Indium, and Intermetallic compounds growth

The gold-indium system is of primary interest for bonding processes such as solid-liquid interdiffusion bonding. In order to optimize the manufacturing parameters, it is essential to know which intermetallic compounds (IMCs) are formed when solid Au and liquid In are brought into close contact with each other, and what are their growth kinetics. For this purpose, we fabricated diffusion couples above and below the melting point of In (for T = 250 and 150 °C respectively). Three IMCs, identified as AuIn2, AuIn and Au7In3, are always observed in the reaction zone, even after short times. AuIn2 is the thickest and fastest growing layer and AuIn is only present as a thin layer. Whereas AuIn2 and AuIn exhibit an equiaxed structure, Au7In3 is found to grow as columnar grains. The diffusion coefficients in each phase were determined by means of a 1-D finite difference modelling of In diffusion. The values are consistent and can be used to predict the growth rate as a function of temperature and time, i.e. to simulate a whole bonding process with finite thicknesses.

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, Concentration contrainte, Stress concentration, Concentración restringida, Spannungskonzentration, Durée vie fatigue, Fatigue life, Longevidad fatiga, Ermuedungslebensdauer, Essai fatigue, Fatigue test, Ensayo fatiga, Dauerschwingversuch, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Fatigue, Fatiga, Ermuedung, Propriété mécanique, Mechanical properties, Propiedad mecánica, Corrugated web girders, Fatigue detail category, and Fatigue tests

Corrugated steel plate has been increasingly used in the last 20 years for beam webs in hybrid and composite bridges. Girders with corrugated webs have many advantages over traditional structures with flat webs, but due to the new structural layout, there are still many design questions that need to be solved. In cases with girders with trapezoidally corrugated webs, the determination of the fatigue life is rather difficult because of the complex stress field in the flanges, and the fatigue detail category has also not been elucidated. This topic has gained importance in Hungary related to a highway bridge on the Tisza River designed and constructed between 2006 and 2011. There are only a small number of investigations dealing with the fatigue behaviour of corrugated web girders in the literature. The aim of the current tests published in this paper is the analysis of the fatigue behaviour of the corrugated web girders under pure bending and combined bending and shear. Furthermore, a proposal for the fatigue detail category is developed based on the test results to support the bridge design. The tests were completed to study the effect of the corrugation profile, the normal stress ratio, the effect of the combined normal and shear stresses and the weld size on the fatigue life.

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 martensitique, Martensitic steel, Acero martensítico, Martensitischer Stahl, Amorçage fissure, Crack initiation, Iniciación grieta, Risseinleitung, Diagramme SN, SN diagram, Diagrama SN, Woehler Kurve, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Fatigue, Fatiga, Ermuedung, Limite fatigue, Fatigue limit, Límite fatiga, Ermuedungsgrenze, Propriété mécanique, Mechanical properties, Propiedad mecánica, S-N curve, crack initiation, fatigue limit, and very high cycle fatigue

Rotating bending fatigue test at very high cycle regimes was carried out on martensitic steel of 2Cr13 in air and 3.5% NaCl environment. The result showed that the S-N curve presents a stepwise tendency over the range of 106-108 cycles in both air and 3.5% NaCl environment. In air fatigue, cracks initiated from the sample surface and inclusions at subsurface and no typical fish eye feature in very high cycle fatigue were observed for all samples tested up to 6 × 108 cycles. In 3.5% NaCl solution, a fatigue limit over the range of K06-108 cycles exhibited with the corrosion fatigue strength reduced by 47% compared to the air fatigue. Multiple cracks initiated from surface and the number of crack origins increased with increasing stress level and surface proportion of fatigue propagation increased as number of cycles increased.

Crystallography, Cristallographie cristallogenèse, Chemical industry parachemical industry, Industrie chimique et parachimique, 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, Matériaux particuliers, Specific materials, Matériaux poreux; matériaux granulaires, Porous materials; granular materials, Traitement des matériaux et son effet sur la microstructure et les propriétés, Treatment of materials and its effects on microstructure and properties, Elasticité et anélasticité, Elasticity and anelasticity, 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, Elasticité. Plasticité, Elasticity. Plasticity, Cuivre, Copper, Cobre, Kupfer, Dimension particule, Particle size, Dimensión partícula, Teilchengroesse, Essai traction, Tension test, Ensayo tracción, Zugversuch, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Forme particule, Particle shape, Forma partícula, Forme sphérique, Spherical shape, Forma esférica, Frittage, Sintering, Sinterización, Sintern, Matériau composite, Composite material, Material compuesto, Verbundwerkstoff, Matériau poreux, Porous material, Material poroso, Poroeser Werkstoff, Particule sphérique, Spherical particle, Partícula esférica, Porosité ouverte, Open cell porosity, Porosidad cerrada, Résistance traction, Tensile strength, Resistencia tracción, Zugfestigkeit, Traction uniaxiale, Uniaxial tension stress, Tracción uniaxial, 8105R, 8140J, ScP, Composite, Porous, Sintered, and Tensile

A novel sintered porous metal composite (SPMC) has been developed by sintering a mixture of a high-porosity open-cell copper foam plate and copper powders with spherical particle shape. The sintered density of the SPMC specimens with different copper particle sizes was investigated under different sintering parameters. The SPMC shows a lower sintered density and a higher porosity than the sintered copper powder (SCP). A uniaxial tensile test was used to study the tensile strength and specific strength (strength-to-density ratio) of the SPMC specimens under different sintering parameters. The test result shows that, depending on the sintering parameters, the tensile strength of SPMC specimens with a copper particle size of 50-75 μm ranges from 8.64 MPa to 25.1 MPa and the specific tensile strength ranges from 1.59 kN m/kg to 4.45 kN m/kg. Under the same sintering condition, the tensile strength of the SPMC is lower than that of the SCP while their specific tensile strengths are nearly the same. The sintering temperature has a significant influence on both the tensile strength and the specific tensile strength of the SPMC while the sintering time has less effect.

Crystallography, Cristallographie cristallogenèse, Chemical industry parachemical industry, Industrie chimique et parachimique, 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, Traitement des matériaux et son effet sur la microstructure et les propriétés, Treatment of materials and its effects on microstructure and properties, Ecrouissage, durcissement par déformation; recuit, trempe, revenu, restauration et recristallisation; textures, Cold working, work hardening; annealing, quenching, tempering, recovery, and recrystallization; textures, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Formage, Forming, Propriétés mécaniques. Rhéologie. Mécanique de la rupture. Tribologie, Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology, Elasticité. Plasticité, Elasticity. Plasticity, Adoucissement mécanique, Strain softening, Ablandamiento mecánico, Mechanische Entfestigung, Bande cisaillement, Shear band, Banda cizallamiento, Scherband, Cavité dans réseau, Void, Cavidad en red, Gitterhohlraum, Contrainte écoulement, Flow stress, Tensión flujo, Fliessspannung, Ductilité, Ductility, Ductilidad, Verformungsfaehigkeit, Durcissement déformation, Strain hardening, Endurecimiento deformación, Verfestigung, Défaut cristallin, Crystal defect, Defecto cristalino, Déformation dent de scie, Serrated yielding, Ecoulement plastique, Plastic flow, Flujo plástico, Plastisches Fliessen, Equation constitutive, Constitutive equation, Ecuación constitutiva, Essai compression, Compression test, Ensayo compresión, Druckversuch, Etude comparative, Comparative study, Estudio comparativo, Vergleich, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Formage, Forming, Conformado, Umformen, Grande vitesse, High speed, Gran velocidad, Microstructure, Microestructura, Mikrogefuege, Modèle mathématique, Mathematical model, Modelo matemático, Mathematisches Modell, Propriété mécanique, Mechanical properties, Propiedad mecánica, Ralentissement, Slowing down, Disminución velocidad, Striction (mécanique), Necking, Estricción (mecánica), Viscoplasticité, Viscoplasticity, Viscoplasticidad, Viskoplastizitaet, Vitesse déformation, Strain rate, Velocidad deformación, Verformungsgeschwindigkeit, 8140E, Aluminum alloys, Constitutive behavior, High velocity deformation, and Microstructure evolution

Investigation of macro-micro dynamic mechanical behavior of aluminum alloys is crucial to understand and model high velocity forming processes, e.g. the electromagnetic forming. Therefore, this work presents the experimental investigation of the macro-micro dynamic deformation behavior and related mechanisms of 5A0X alloys. With increasing strain rate, notable hardening and serrated flow curves are observed for both 5A06 and 5A02 alloys; the flow softening ratio increases from 10.59% to 15.56% for 5A06 alloy, while increasing up to 34.55% at a strain rate of 3000 s-1 for 5A02 alloy. High velocity deformation enhances the ductility of both the alloys via slowing down the neck development rather than suspending the onset of necking. Comparative study in dynamic tensile/compressive behavior of 5A06 alloy indicates a similar hardening rule in these two loading conditions, however, more obvious softening is found in tension than that in compression. The difference can be attributed to the different microstructure-related characteristics, namely, the diffuse necking related to void evolution in tension and the adiabatic shear bands (ASB) in compression. In addition, a mathematical model is used in this work to corroborate the occurrence of ASBs and to predict the half width of ASBs, which is proved reliable by experiments.

Crystallography, Cristallographie cristallogenèse, Chemical industry parachemical industry, Industrie chimique et parachimique, Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Structure des liquides et des solides; cristallographie, Structure of solids and liquids; crystallography, Structure de solides cristallins particuliers, Structure of specific crystalline solids, 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, Rupture, Fractures, Amorçage fissure, Crack initiation, Iniciación grieta, Risseinleitung, Diffraction électron rétrodiffusé, EBSD, Diffractión electrón retrodifusa, Défaut cristallin, Crystal defect, Defecto cristalino, Déformation plastique, Plastic deformation, Deformación plástica, Plastische Verformung, Eprouvette entaillée, Notched test piece, Probeta entallada, Kerbpruefkoerper, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Fissure, Crack, Fisura, Riss, Fracture, Fractura, Glissement, Slip, Deslizamiento, Gleiten, Interface, Interfase, Grenzflaeche, Maclage, Twinning, Chocleo, Zwillingsbildung, Macle, Crystal twin, Macla, Zwilling, Magnésium, Magnesium, Magnesio, Monocristal, Single crystal, Einkristall, Métallographie, Metallography, Metalografía, Metallographie, Orientation cristalline, Crystal orientation, Orientación cristalina, Kristallorientierung, Propriété mécanique, Mechanical properties, Propiedad mecánica, Rupture, Ruptura, Bruch, Structure cristalline, Crystalline structure, Estructura cristalina, Kristallstruktur, Ténacité, Fracture toughness, Tenacidad, Bruchzaehigkeit, Crack deflection, Fracture behavior, Magnesium single crystals, and Tensile twinning

In this work, the fracture behavior of magnesium single crystals is studied by conducting experiments with notched three point bend specimens of three crystallographic orientations. In the first and second orientations, the c-axis is along the normal to the flat surface of the notch, while in the third it is aligned with the notch front. For all the orientations, in situ electron back scattered diffraction observations made around the notch root show profuse tensile twinning of {102}―type. Further, in the first two orientations basal and prismatic slip traces are identified from optical metallography. The width of the most prominent twin saturates at around 120―150 μm, while twins continue to nucleate farther away to accommodate plastic deformation. In all the orientations, crack initiation occurs before the attainment of peak load and the crack grows stably along twin―matrix interface before deflecting at twin―twin intersections. Results show that profuse tensile twinning is an important energy dissipating mechanism that enhances the fracture toughness.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Corrosion, Action des agents de corrosion, Corrosion environments, Protection contre la corrosion, Corrosion prevention, Acide chlorhydrique, Hydrochloric acid, Ácido chlorhídrico, Salzsaeure, Acier non allié, Carbon steel, Acero no aliado, Unlegierter Stahl, Corrosion acide, Acid corrosion, Corrosión ácido, Saeurekorrosion, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Impédance, Impedance, Impedancia, Inhibiteur corrosion, Corrosion inhibitor, Inhibidor corrosión, Korrosionsinhibitor, Microscopie électronique balayage, Scanning electron microscopy, Microscopía electrónica barrido, Rasterelektronenmikroskopie, Protection corrosion, Corrosion protection, Protección corrosión, Korrosionsschutz, A. Mild steel, B. EIS, B. SEM, and C. Acid corrosion

The effect of 2-Pyridinecarbonitrile (2-PCN) was studied on mild steel (MS) corrosion in 0.1 mol L-1 HCl by electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR) and potentiodynamic polarization measurements. The surface morphologies of the MS were investigated in the inhibitor-free and in the presence of 10 mmol L-1 2-PCN containing corrosive media, at 120 h exposure period by scanning electron microscopy (SEM). The mechanism of adsorption was determined from the potential of zero charge (Epzc). 2-PCN adsorption on the MS surface obeyed the isotherm of Langmuir and the thermodynamic parameters Kads; ΔGads were also calculated and discussed.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Corrosion, Action des agents de corrosion, Corrosion environments, Protection contre la corrosion, Corrosion prevention, Acide chlorhydrique, Hydrochloric acid, Ácido chlorhídrico, Salzsaeure, Aluminium, Aluminio, Corrosion, Corrosión, Korrosion, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Etude théorique, Theoretical study, Estudio teórico, Theoretische Untersuchung, Impédance, Impedance, Impedancia, Inhibiteur corrosion, Corrosion inhibitor, Inhibidor corrosión, Korrosionsinhibitor, Modélisation, Modeling, Modelización, Oxime, Oxima, Perte masse, Mass loss, Pérdida masa, Protection corrosion, Corrosion protection, Protección corrosión, Korrosionsschutz, A. Aluminium, B. EIS, B. Modelling studies, B. Polarization, B. Weight loss, and C. Acid inhibition

The inhibition effect of three oxime compounds of acetone oxime (AO), 2-butanone oxime (BO) and cyclohexanone oxime (CO) on the corrosion of aluminium in HCl solution was studied by weight loss, potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), quantum chemical calculation and molecular dynamics (MD) simulation methods. The results show that all oxime compounds are good inhibitors, and inhibition efficiency follows the order: CO > BO > AO. The adsorption of each inhibitor on aluminium surface obeys Langmuir adsorption isotherm. All these oxime compounds act as cathodic inhibitors. The probable inhibitive mechanism is proposed from the viewpoint of adsorption theory.

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, Propriétés mécaniques. Rhéologie. Mécanique de la rupture. Tribologie, Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology, Propriété mécanique, Mechanical properties, Propiedad mecánica, Alliage base aluminium, Aluminium base alloys, Equation constitutive, Constitutive equation, Ecuación constitutiva, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Frottement, Friction, Frotamiento, Reibung, Mesure température, Temperature measurement, Medida temperatura, Temperaturmessung, Microstructure, Microestructura, Mikrogefuege, Modélisation, Modeling, Modelización, Soudage friction, Friction welding, Soldeo por fricción, Reibschweissen, Température, Temperature, Temperatura, Temperatur, and von Mises stress

This paper highlights the role of globular microstructure on the weldability of semi-solid processed aluminum alloys via high temperature flow behavior. The investigation was carried out on the joining of thixocast A356 aluminum alloy components by friction welding. A thermomechanical model was developed to predict the temperature and stress distributions, as well as to identify the suitable and safe range of parameters. Good comparisons between numerical and experimental results were observed. In addition, metallographic examinations and hardness and tensile tests of the welded samples were carried out. It was found that the tensile strength of the joint is higher than the tensile strength of the parent material for the optimum set of parameters.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Corrosion, Action des agents de corrosion, Corrosion environments, Protection contre la corrosion, Corrosion prevention, Application, Aplicación, Anwendung, Corrosion électrochimique, Electrochemical corrosion, Corrosión electroquímica, Elektrochemische Korrosion, Défaut, Defect, Defecto, Fehler, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Industrie pétrolière, Oil industry, Industria petrolera, Erdoelindustrie, Modélisation, Modeling, Modelización, Pipeline, Oleoducto, Protection cathodique, Cathodic protection, Protección catódica, Kathodischer Schutz, Protection corrosion, Corrosion protection, Protección corrosión, Korrosionsschutz, A. Steel, B. Modelling studies, and C. Cathodic protection

In this work, the effectiveness of cathodic protection (CP) at corrosion defects on an X100 steel pipeline was investigated both experimentally and numerically. A finite element model was developed to simulate distributions of local potential and anodic/cathodic current density inside the defect. Results demonstrated that there is a non-uniform potential and current distribution at corrosion defects. The CP is shielded, at least partially, at the defect, especially at its bottom. This effect is enhanced with increasing depth and decreasing width of the defect. Empirical equations are derived to enable calculation of CP effectiveness at corrosion defects, providing industry recommendations for accurate assessment of further corrosion allowance and remaining life of pipelines in the field.