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Chemical engineering, Génie chimique, Mechanical engineering, Génie mécanique, Mechanics acoustics, Mécanique et acoustique, Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Domaines classiques de la physique (y compris les applications), Fundamental areas of phenomenology (including applications), Mécanique des solides, Solid mechanics, Mécanique des structures et des milieux continus, Structural and continuum mechanics, Mécanique de la rupture (fissure, fatigue, endommagement...), Fracture mechanics (crack, fatigue, damage...), Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Corrosion, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Métrologie industrielle. Contrôle, Industrial metrology. Testing, Généralités, General, Organes de machines, Machine components, Frottement, usure, lubrification, Friction, wear, lubrication, Cage roulement, Bearing cage, Caja rodillos, Caloduc, Heat pipe, Tubo de calor, Waermerohr, Chaudière, Boiler, Caldera, Dampfkessel, Corrosion piqûre, Pitting corrosion, Corrosión superficial, Lochkorrosion, Corrosion sous tension, Stress corrosion, Corrosión bajo tensión, Spannungsrisskorrosion, Couplage, Coupling, Acoplamiento, Denture engrenage, Gear tooth, Dentado engranaje, Echangeur chaleur, Heat exchanger, Intercambiador calor, Waermeaustauscher, Endommagement, Damaging, Deterioración, Entretien préventif, Preventive maintenance, Entretenimiento preventivo, Essai non destructif, Non destructive test, Ensayo no destructivo, Zerstoerungsfreie Pruefung, Essai usure, Wear test, Prueba al desgaste, Verschleissversuch, Fissuration, Cracking, Agrietamiento, Rissbildung, Fissure, Crack, Fisura, Riss, Fractographie, Fractography, Fractografía, Fraktographie, Micrographie, Micrography, Micrografía, Mikrophotographie, Microscopie optique, Optical microscopy, Microscopía óptica, Optische Mikroskopie, Morphologie, Morphology, Morfología, Métallographie, Metallography, Metalografía, Metallographie, Palier, Bearing(mechanics), Descansillo, Lager, Piqûre corrosion, Pinhole, Picadura corrosión, Randblase, Propagation fissure, Crack propagation, Propagación fisura, Rissausbreitung, Rainure, Groove, Ranura, Rupture, Ruptura, Bruch, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Tribologie, Tribology, Tribología, Electric corrosion, NDT, Predictive maintenance, and Replica metallography

Polymeric replica, as a non-destructive technique, is generally used for detecting service failures in mechanical components together with other complementary methods. The components more frequently inspected are boilers, streamers, heat exchangers, pipes. In most cases, this technique fulfills the requirement of non-surface modifications of the damaged zone, be it a fracture surface, a gear tooth, a bearing raceway or any other part. Fracture and corrosion are the type of failures usually studied with this technique. It allows the description of crack morphology and propagation type, and is also a tool to differentiate crevice corrosion, stress corrosion cracking, pitting corrosion, etc. As far as we know, this technique has not been used so far to detect wear failures, to measure scar size (volume or critical dimensions) or to determine the type of wear failure. In this study, polymeric replicas are used to find the root cause of electric corrosion failures or spark-erosion wear in different gear-tooth coupling of feedwater pumps that convey light water to the steam generators at a Nuclear Power Plant in Argentina (CNE NPP). By means of this in situ and non-destructive technique we have been able to describe failures, originated in engine electrostatic losses. It was determined that parasitic currents were distributed in the whole transmission line, and the sparks on the gear's teeth melted small hemispheric drops of metal producing micro voids or craters. In order to copy the wear scars, foils of cellulose acetate replicas were used on the surfaces and a special elastomer rubber was also applied, filling the space between the teeth. The scar copies were observed by means of optical microscopy. The micrographies have allowed the characterization of microscopic holes (of 100 μm diameter) produced by electric discharges.

Electronics, Electronique, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Electronique, Electronics, Matériaux, Materials, Barrière diffusion, Diffusion barrier, Barrera difusión, Constante diélectrique, Permittivity, Constante dieléctrica, Couche mince, Thin film, Capa fina, Couche superficielle, Surface layer, Capa superficial, Diélectrique basse permittivité, Low k dielectric, Dieléctrico baja constante dieléctrica, Nucléation, Nucleation, Nucleación, Optimisation, Optimization, Optimización, Propriété surface, Surface properties, Propiedad superficie, Silicium oxyde, Silicon oxides, Traitement surface, Surface treatment, Tratamiento superficie, O Si, Ru, SiO2, UV-O3, diffusion barrier, low-k, and surface modification

The UV-O3 treatment effects on the structural properties of low-k films as a function of the treatment time were investigated in this study. The thickness of the samples proportionally decreased with the surface treatment time due to highly reactive ozone and the process gradually modified surface layer more SiO2-like. Excessive treatment of longer than 60 s adversely affected the low-k film, increasing the dielectric constant of underlying low-k film. After the UV-O3 treatment for the optimized treatment time of 60 s, the poor nucleation problem of Ru deposition was solved and fully-covered Ru film on low-k film was obtained.

Chemical engineering, Génie chimique, Mechanical engineering, Génie mécanique, Mechanics acoustics, Mécanique et acoustique, Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Domaines classiques de la physique (y compris les applications), Fundamental areas of phenomenology (including applications), Mécanique des solides, Solid mechanics, Mécanique des structures et des milieux continus, Structural and continuum mechanics, Mécanique de la rupture (fissure, fatigue, endommagement...), Fracture mechanics (crack, fatigue, damage...), Sciences appliquees, Applied sciences, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Organes de machines, Machine components, Frottement, usure, lubrification, Friction, wear, lubrication, Acier allié, Alloy steel, Acero aliado, Acier construction, Structural steel, Acero construcción, Adhérence, Adhesion, Adherencia, Carbone adamantin, Diamond like carbon, Carbono adiamantino, Coefficient frottement, Friction coefficient, Coeficiente roce, Dureté superficielle, Surface hardness, Dureza superficial, Délaminage, Delamination, Delaminación, Essai adhérence, Adhesion test, Ensayo adherencia, Essai frottement, Friction test, Prueba frotamiento, Essai usure, Wear test, Prueba al desgaste, Force adhérence, Adhesive strength, Fuerza adherencia, Grenaillage, Shot peening, Granalla, Machine mouvement alternatif, Reciprocating movement machine, Máquina movimiento alterno, Mélangeage, Mixing, Mezclado, Métal, Metal, Particule fine, Fine particle, Partícula fina, Revêtement, Coatings, Revestimiento, Rugosité, Roughness, Rugosidad, Surface rugueuse, Rough surface, Superficie rugosa, Traitement surface, Surface treatment, Tratamiento superficie, Tribologie, Tribology, Tribología, Usure glissement, Sliding wear, Desgaste deslizamiento, Delamination of coatings, Diamond-like carbon, Diffused layer, and Surface modification

To improve the poor adhesion of diamond-like carbon (DLC) coatings to steel substrates, we have proposed a hybrid surface treatment, which is a combination of fine particle bombardment (FPB) and DLC coating. Specimens were treated by FPB using Cr shot particles prior to coating with DLC by the ionizing deposition method. Specimens with only the DLC coating without the FPB treatment (single-treated) were also prepared. The FPB treatment increased substrate hardness and roughness. In addition, a Cr-rich layer was formed on the surface because of the mechanical mixing of Cr shot particles into steel substrate. Reciprocating sliding wear tests were conducted to investigate the coefficient of friction. While the single-treated specimens showed a sudden increase in the friction coefficient resulting from delamination of the DLC coating, the hybrid-treated specimens maintained a low friction coefficient during wear tests indicating strong adhesion of the DLC coating. The reasons for good adhesion of the hybrid-treated specimens were investigated in terms of surface hardness and Cr enrichment. The relationship between substrate hardness and friction coefficient was investigated by preparing substrates with different hardness values. The results indicated that an increase in hardness is effective in suppressing of DLC coatings delamination, whereas a significant increase in hardness was not achieved by the FPB treatment. A roughened substrate without the Cr-rich layer was also prepared to examine the effects of substrate roughness and the presence of Cr. The results imply that strong adhesion of the DLC coating of the hybrid-treated specimens was due to the presence of Cr, which suppressed the delamination of the DLC coatings.

Chemical engineering, Génie chimique, Mechanical engineering, Génie mécanique, Mechanics acoustics, Mécanique et acoustique, Metallurgy, welding, Métallurgie, soudage, 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, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Organes de machines, Machine components, Frottement, usure, lubrification, Friction, wear, lubrication, Acier cémenté, Case hardened steel, Acero cementado, Acier inoxydable 316, Stainless steel-316, Acier inoxydable austénitique, Austenitic stainless steel, Acero inoxidable austenítico, Austenitischer nichtrostender Stahl, Acier inoxydable, Stainless steel, Acero inoxidable, Nichtrostender Stahl, Acier non allié, Carbon steel, Acero no aliado, Unlegierter Stahl, Carbone, Carbon, Carbono, Kohlenstoff, Contact glissant, Sliding contact, Contacto deslizante, Cémentation, Carburizing, Cementación, Aufkohlen, Durcissement superficiel, Surface hardening, Endurecimiento superficial, Dureté superficielle, Surface hardness, Dureza superficial, Oberflaechenhaerte, Essai pion disque, Pin disk test, Ensayo barra disco, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Frottement sec, Dry friction, Frotamiento seco, Haute température, High temperature, Alta temperatura, Hochtemperatur, Module déformation, Deformation modulus, Módulo deformación, Métal, Metal, Metalle, Résistance corrosion, Corrosion resistance, Resistencia corrosión, Korrosionsbestaendigkeit, Sel, Salt, Sal, Salz, Température ambiante, Room temperature, Temperatura ambiente, Raumtemperatur, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Tribologie, Tribology, Tribología, Colossal supersaturation carburization, Corrosion-resistance, and Wear-resistance

A promising, alternative surface treatment to traditional case carburizing was recently developed. It enables extremely high ('colossal') supersaturation of carbon (up to 12 at.%) in austenitic stainless steel surfaces. This new treatment offers the advantage of hardening the surface while still retaining the corrosion resistance of stainless steels. In this study, the tribological properties of the colossal supersaturation carburized Type 316 stainless steel were investigated and benchmarked against non-treated steel. The carburized surfaces exhibited higher hardness, higher elastic modulus, and higher resistance to acid etching than non-treated surfaces. Hot hardness measurements were conducted and linear relations between the hardness and temperature were observed for both treated and non-treated specimens. The friction and wear characteristics were evaluated at both room and elevated temperatures (200 and 400 °C) under non-lubricated sliding conditions (pin-on-disk). Additional room-temperature tests were performed in salt water. Improved wear-resistance was observed on the treated surfaces at all test conditions, though less benefit was observed at elevated temperatures or in salt water.

Chemical engineering, Génie chimique, Mechanical engineering, Génie mécanique, Mechanics acoustics, Mécanique et acoustique, Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Organes de machines, Machine components, Frottement, usure, lubrification, Friction, wear, lubrication, Abrasif, Abrasives, Abrasivo, Contrainte contact, Contact stress, Tensión contacto, Dureté, Hardness, Dureza, Erosion, Erosión, Etat surface, Surface conditions, Estado superficie, Finissage surface, Surface finishing, Matériau dur, Hard material, Material duro, Optimisation, Optimization, Optimización, Palier roulement, Rolling bearing, Cojinete rodillos, Pression contact, Contact pressure, Presión contacto, Processus fabrication, Production process, Proceso fabricación, Roulement rouleau, Roller bearing, Rodamiento rodillo, Rugosité, Roughness, Rugosidad, Surface contact, Contact surface, Superficie contacto, Surface rugueuse, Rough surface, Superficie rugosa, Texture, Textura, Traitement surface, Surface treatment, Tratamiento superficie, Tribologie, Tribology, Tribología, Usinage, Machining, Mecanizado, Usure abrasive, Abrasive wear, Desgaste abrasivo, Abrasion, Abrasive film, Belt finishing, and Surface roughness

The belt finishing process is a recent manufacturing technique in the field of superfinishing of hard material. Its mechanisms have not yet been fully explained. This paper attempts to make a contribution to the understanding of the wear mechanisms of the abrasive film and its influence on surface roughness. First, the contact conditions between abrasive film and the surface have been analysed and the abrasive film wear has been theoretically modelled. Effective contact duration between grains and machined surface on the one hand, and average contact pressure on the other hand have been introduced as key parameters. Then, the effects of the most influential belt finishing parameters and their interactions on the surface roughness and the material removal have been experimentally investigated. It was revealed the existence of an optimum surface roughness reachable independently of the force and of the roller's hardness. It has also been revealed the existence of an optimum belt finishing duration depending on the feed, the force and on the roller's hardness.

Chemical engineering, Génie chimique, Mechanical engineering, Génie mécanique, Mechanics acoustics, Mécanique et acoustique, Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Corrosion, 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, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Organes de machines, Machine components, Frottement, usure, lubrification, Friction, wear, lubrication, Alliage Ti90Al6V4, Alloy-Ti90Al6V4, Alliage base titane, Titanium base alloys, Durabilité, Durability, Durabilidad, Essai corrosion, Corrosion test, Ensayo corrosión, Korrosionsversuch, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Passivité, Passivity, Pasividad, Passivitaet, Pulvérisation cathodique, Cathodic sputtering, Pulverización catódica, Kathodenzerstaeubung, Pulvérisation irradiation, Sputtering, Pulverización irradiación, Sputtern, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Régime déséquilibré, Unbalanced conditions, Régimen desequilibrado, Sodium chlorure, Sodium chloride, Sodio cloruro, Natriumchlorid, Titane alliage, Titanium alloy, Titanio aleación, Titanlegierung, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Traitement thermique, Heat treatment, Tratamiento térmico, Waermebehandlung, Tribologie, Tribology, Tribología, Usure corrosive, Corrosive wear, Desgaste corrosivo, Korrosiver Verschleiss, Usure glissement, Sliding wear, Desgaste deslizamiento, Gleitverschleiss, Vibration, Vibración, Schwingung, Vide, Vacuum, Vacío, Vakuum, Corrosion-wear, Cr-Ti coatings, and Laves phase

Titanium alloys display problematic behaviour in environments where wear and corrosion take place either simultaneously or sequentially. While various surface treatments have been proposed for the alleviation of corrosion and wear of Ti-6Al-4V, there is still scope for new and novel approaches. In the work reported here, three coating compositions: Cr-13 at.%Ti, Cr-33 at.%Ti and Cr-48 at.%Ti, were synthesised by unbalanced magnetron sputter deposition and applied to Ti-6Al-4V substrates. In the as deposited state the coatings were single phased, while subsequent vacuum heat treatment at 800 °C resulted in the formation of the Laves phase (α-TiCr2). Coated Ti-6Al-4V test pieces were subjected to reciprocation sliding corrosion-wear tests in 0.9% NaCl solution at 37 °C. All the coated variants tested showed a reduction in corrosion-wear compared to uncoated Ti-6Al-4V. The most effective coatings were those that contained the Laves phase (α-TiCr2). It is proposed that the passive film formed on the Laves phase had greater mechanical integrity than any others formed during corrosion-wear testing and this phenomenon was a key factor in providing the observed enhanced surface durability.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Chemical engineering, Génie chimique, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Théorie des réactions, cinétique générale. Catalyse. Nomenclature, documentation chimique, informatique chimique, Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry, Catalyse, Catalysis, Physicochimie de surface, Surface physical chemistry, Matériaux adsorbants, Adsorbents, Etat colloïdal et états dispersés, Colloidal state and disperse state, Matériaux poreux, Porous materials, Sciences appliquees, Applied sciences, Energie, Energy, Combustibles, Fuels, Combustibles de remplacement. Production et utilisation, Alternative fuels. Production and utilization, Hydrogène, Hydrogen, Métal transition, Transition metal, Metal transición, Adsorption, Adsorción, Catalyse hétérogène, Heterogeneous catalysis, Catálisis heterogénea, Charbon actif, Activated carbon, Carbón activado, Dopage, Doping, Fibre carbone, Carbon fiber, Fibra carbón, Fluoration, Fluorination, Fluoración, Hydrogène, Hydrogen, Hidrógeno, Nickel, Niquel, Porosité, Porosity, Porosidad, Propriété surface, Surface properties, Propiedad superficie, Stockage, Storage, Almacenamiento, Traitement surface, Surface treatment, Tratamiento superficie, Activated carbon fiber, Hydrogen storage, and Nickel doping

In this study, activated carbon fibers (ACFs) with high surface area and pore volume have been modified by Ni doping and fluorination. The surface modified ACFs were characterized by BET surface area, SEM/EDS, XRD, and Raman spectroscopy. The changes in pore structure and surface properties of these modified ACFs were correlated with hydrogen storage capabilities. After fluorination treatment, although the micropore volume of ACF was decreased, amounts of hydrogen storage were found to increase. Additionally, micropore volume on ACFs was found to be unchanged with Ni doping, hydrogen storage capacities were considerably increased due to the effect of catalytic activation of nickel. Though fluorination of ACFs increases hydrogen affinity, the effect of catalytic activation of nickel is more prominent, and thus led to better hydrogen storage. Hence, it was concluded that hydrogen storage capacity was related to micropore volumes, Pore size distribution (PSD) and surface properties of ACFs as well as specific surface areas.

Chemical engineering, Génie chimique, Mechanical engineering, Génie mécanique, Mechanics acoustics, Mécanique et acoustique, Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Organes de machines, Machine components, Frottement, usure, lubrification, Friction, wear, lubrication, Durabilité, Durability, Durabilidad, Erosion, Erosión, Industrie automobile, Automobile industry, Industria automóvil, Particule solide, Solid particle, Partícula sólida, Peinture, Paint, Pintura, Plaque, Plate, Placa, Polymère, Polymer, Polímero, Procédé dépôt, Deposition process, Procedimiento revestimiento, Procédé revêtement, Coating process, Recyclage, Recycling, Reconversión, Revêtement plastique, Plastic coating, Revestimiento plástico, Rugosité, Roughness, Rugosidad, Sablage, Sand blasting, Enarenación, Surface rugueuse, Rough surface, Superficie rugosa, Traitement surface, Surface treatment, Tratamiento superficie, Tribologie, Tribology, Tribología, Chrome plate, Recovery, and Stripping

In the automotive industry, polymer components are routinely employed in a wide variety of situations. Where such components are employed in visible applications, their aesthetic appeal is commonly enhanced by the application of surface coatings, such as paints or chrome plate. However, throughout the lifecycle of the component, coating removal may be required to enhance its ability to be reused or recycled. For example, following the coating processes, it is commonly found that a significant number of components fall below the quality specified and as such remedial action is required. There are a number of routes available: (i) recycling of the component in the as-coated state; (ii) recycling of the component following removal of the coating, allowing a higher value product to be realised; (iii) recoating of the component following removal of the defective coating. The last of these options has restrictions on the surface roughness of the substrate following coating removal. Again, at the end of component life, the recovery of high value material may be enhanced by the removal of coatings, although here, the surface condition of the substrate is not an issue of concern. This paper examines the use of solid particle blasting with spherical glass particles as a means of coating removal for two industrially relevant systems, namely paint coatings on polypropylene blend substrates and chrome coatings on ABS substrates. It was found that paint could be removed from the substrates, but that a very large dose of particles was required. The high compliance of both the coating and the substrate resulted in the difficulty in removing the paint films. In contrast, the chrome coatings could successfully be removed from the ABS substrates at low particle doses. The possibility of recoating of the ABS substrates following coating removal was assessed in light of the roughness developed by the removal of the coating.

Electronics, Electronique, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Instruments, appareillage, composants et techniques communs à plusieurs branches de la physique et de l'astronomie, Instruments, apparatus, components and techniques common to several branches of physics and astronomy, Techniques et équipements généraux, General equipment and techniques, Capteurs (chimiques, optiques, électriques, de mouvement, de gaz, etc.); télédétection, Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing, Sciences appliquees, Applied sciences, Electronique, Electronics, Electronique des semiconducteurs. Microélectronique. Optoélectronique. Dispositifs à l'état solide, Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices, Circuits intégrés, Integrated circuits, Conception. Technologies. Analyse fonctionnement. Essais, Design. Technologies. Operation analysis. Testing, Dispositifs micro- et nanoélectromécaniques (mems/nems), Micro- and nanoelectromechanical devices (mems/nems), Adressage, Addressing, Direccionamiento, Circuit VLSI, VLSI circuit, Circuito VLSI, Circuit intégré, Integrated circuit, Circuito integrado, Dispositif nanoélectromécanique, Nanoelectromechanical device, Dispositivo nanoelectromecánico, Dispositif électromécanique, Electromechanical device, Dispositivo electromecánico, Détecteur proximité, Proximity detector, Detector proximidad, Electronique de mesure, Readout electronics, Interconnexion, Interconnection, Interconexión, Logiciel, Software, Logicial, Nanotechnologie, Nanotechnology, Nanotecnología, Poutre cantilever, Cantilever beam, Viga cantilever, Système mécanique, Mechanical system, Sistema mecánico, Traitement surface, Surface treatment, Tratamiento superficie, 0707D, Cantilever arrays, Piezoresistive micro-cantilever, and Self-actuated micro-cantilever

A major limitation for future nanotechnology, particularly for bottom-up manufacturing is the non-availability of 2-dimensional massively parallel probe arrays. Scanning proximity probes are uniquely powerful tools for analysis, manipulation and bottom-up synthesis: they are capable of addressing and engineering surfaces at the atomic level and are the key to unlocking the full potential of Nanotechnology. Generic massively parallel intelligent cantilever-probe platforms is demonstrated through a number of existing and ground-breaking techniques. A packaged VLSI NEMS-chip (Very Large Scale Integrated Nano Electro Mechanical System) incorporating 128 proximal probes, fully addressable with control and readout interconnects and advanced software will be presented.

Chemical engineering, Génie chimique, Mechanical engineering, Génie mécanique, Mechanics acoustics, Mécanique et acoustique, Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Organes de machines, Machine components, Frottement, usure, lubrification, Friction, wear, lubrication, Alumine, Alumina, Alúmina, Boue liquide, Slurries, Composition chimique, Chemical composition, Composición química, Céramique oxyde, Oxide ceramics, Cerámica óxido, Frottement, Friction, Frotamiento, Hydrogène, Hydrogen, Hidrógeno, Indentation, Indentación, Microdureté, Microhardness, Microdureza, Microscopie RX, X ray microscopy, Microscopía rayos X, Microscopie électronique balayage, Scanning electron microscopy, Microscopía electrónica barrido, Modèle milieu effectif, Effective medium model, Modelo medio efectivo, Métal, Metal, Métrologie surface, Surface metrology, Metrología superficie, Nanoindentation, Nanoindentacion, Nanoparticule, Nanoparticle, Nanopartícula, Oxydation, Oxidation, Oxidación, Passivation, Pasivación, Polissage chimique, Chemical polishing, Pulido químico, Polissage mécanique, Mechanical polishing, Pulido mecánico, Propriété chimique, Chemical properties, Propiedad química, Propriété surface, Surface properties, Propiedad superficie, Spectrométrie RX, X ray spectrometry, Espectrometría RX, Spectrométrie photoélectron, Photoelectron spectrometry, Espectrometría fotoelectrón, Suspension particule, Particle suspension, Suspensión partícula, Traitement surface, Surface treatment, Tratamiento superficie, Usinage, Machining, Mecanizado, Abrasion, Chemical-mechanical planarization (CMP), and Wear

This paper studies surface properties of metals during chemical-mechanical polishing (CMP). In order to pinpoint the effects of chemistry and mechanical impacts separately, during CMP, we polished Cu and Al surfaces using two distinct slurries of hydrogen peroxide (H2O2) and alumina nanoparticles. After polishing, detailed characterization of the surface quality and chemical composition were conducted using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and nanoindentation techniques. It was found that nanoparticles were effective in removing surface materials while passivation provides a high quality layer. The application of H2O2 slurries in combination with friction stimulation produced an oxide layer. Depending on the nature of metals, it was found that Cu forms an active and non-equilibrium oxide layer while Al has a stable one. The oxide layer resulted from two competing mechanisms, passivation and abrasion. It was deduced from kinetics that oxidation dominated the initial formation of the surface layer while mechanical sweeping determined the final film thickness. New material-removal mechanisms are proposed.

Chemical engineering, Génie chimique, Mechanical engineering, Génie mécanique, Mechanics acoustics, Mécanique et acoustique, Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Domaines classiques de la physique (y compris les applications), Fundamental areas of phenomenology (including applications), Mécanique des solides, Solid mechanics, Mécanique des structures et des milieux continus, Structural and continuum mechanics, Inélasticité (thermoplasticité, viscoplasticité...), Inelasticity (thermoplasticity, viscoplasticity...), Sciences appliquees, Applied sciences, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Organes de machines, Machine components, Frottement, usure, lubrification, Friction, wear, lubrication, Austénite, Austenite, Austenita, Echelle nanométrique, Nanometer scale, Etude expérimentale, Experimental study, Estudio experimental, Ferrite, Ferrita, Frottement, Friction, Frotamiento, Grosseur grain, Grain size, Grosor grano, Inélasticité, Inelasticity, Inelasticidad, Matériau cristallin, Crystalline material, Material cristalino, Microscopie électronique transmission, Transmission electron microscopy, Microscopía electrónica transmisión, Microstructure, Microestructura, Morphologie, Morphology, Morfología, Plasticité, Plasticity, Plasticidad, Radioisotope, Radionúclido, Résistance frottement, Frictional resistance, Resistencia rozamiento, Structure cristalline, Crystalline structure, Estructura cristalina, Structure grain fin, Fine grain structure, Estructura grano fino, Subsurface, Subsuelo, Traitement surface, Surface treatment, Tratamiento superficie, Tribologie, Tribology, Tribología, Usure, Wear, Desgaste, Vitesse usure, Wear rate, Velocidad desgaste, Hardening, Low wear rate, Nano-crystalline layer, and Third body

Wear in modem tribological systems is characterized by ultra-low rates in the order of a few nanometers per hour. Even under low wear conditions, morphology, crystalline arrangement, and chemical bonds of surface and subsurface are modified significantly and considerable plastic deformation occurs up to 1 μm depth. We characterize these changes with the help of tribometer experiments employing the radionuclide technique and transmission electron microscopy (TEM). The tribological conditions lead to complex and strongly inhomogeneous layered structures. The top zone of the subsurface has a nano-crystalline structure with an average grain size of about 10 nm containing ferrite, austenite, and cementite phases. Below the subsurface material consists of a work-hardened, fine-grained structure. Our experiments lead us to conclude that the observed combination of a nano-crystalline top layer and a work-hardened subsurface favours high wear resistance and low friction.

Electronics, Electronique, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Electronique, Electronics, Matériaux, Materials, Caractéristique électrique, Electrical characteristic, Característica eléctrica, Courant fuite, Leakage current, Corriente escape, Densité courant, Current density, Densidad corriente, Diélectrique permittivité élevée, High k dielectric, Dieléctrico alta constante dieléctrica, Eau, Water, Agua, Fiabilité, Reliability, Fiabilidad, Grille transistor, Transistor gate, Rejilla transistor, Hafnium oxyde, Hafnium oxide, Hafnio óxido, Multicouche, Multiple layer, Capa múltiple, Ozonation, Ozonization, Ozonización, Piégeage porteur charge, Charge carrier trapping, Captura portador carga, Silicium, Silicon, Silicio, Traitement surface, Surface treatment, Tratamiento superficie, H O, H2O, Hf O, HfO2, Si, charge trapping, high-κ, ozone, reliability, and surface treatment

In this study, we improved the interfacial properties of high-κ gate stacks with the surface treatment of ozonated water prior to deposition of hafnium oxide (HfO2). We demonstrated that the Ozone-oxide improved the electrical properties of the HfO2 gate stack interface in terms of its smoother interface, lower leakage current density, narrower hysteresis width, superior charge trapping effect, and reliability. From these experimental results, we believe that treatment with ozone is an efficient method for the preparation of high-quality interfaces between HfO2 and silicon surfaces.

Electronics, Electronique, 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, Dispositifs à structure composée, Compound structure devices, Fabrication microélectronique (technologie des matériaux et des surfaces), Microelectronic fabrication (materials and surfaces technology), Electronique moléculaire, nanoélectronique, Molecular electronics, nanoelectronics, Caractéristique électrique, Electrical characteristic, Característica eléctrica, Diélectrique permittivité élevée, High k dielectric, Dieléctrico alta constante dieléctrica, Electronique faible puissance, Low-power electronics, Fabrication microélectronique, Microelectronic fabrication, Fabricación microeléctrica, Implantation ion, Ion implantation, Implantación ión, Nanotechnologie, Nanotechnology, Nanotecnología, Nanoélectronique, Nanoelectronics, Nanoelectrónica, Nitruration, Nitriding, Nitruración, Structure MOS, MOS structure, Estructura MOS, Traitement surface, Surface treatment, Tratamiento superficie, HfOxNy, high-k gate dielectric, nitridation treatment, and plasma immersion ion implantation

High-k gate dielectric process is the key technology for nano-scale MOS device. A nitridation treatment on silicon surface is promising for characteristic improvement on high-k dielectric. It is found in this work that the electrical characteristics of high-k gated MOS devices can be improved by a nitridation treatment at silicon surface using plasma immersion ion implantation (PIII) at low ion energy and with a short implantation time. A shallow nitrogen profile at Si surface is known to be favorable for further enhancement of device properties.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Corrosion, Action des agents de corrosion, Corrosion environments, Corrosion atmosphérique, Atmospheric corrosion, Corrosión atmosférica, Atmosphaerische Korrosion, Dépôt immersion, Dip coating, Depósito inmersión, Tauchbeschichten, Interface, Interfase, Grenzflaeche, Microscopie électronique transmission, Transmission electron microscopy, Microscopía electrónica transmisión, Transmissionselektronenmikroskopie, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Résistance corrosion, Corrosion resistance, Resistencia corrosión, Korrosionsbestaendigkeit, Structure lamellaire, Lamellar structure, Estructura lamelar, Lamellargefuege, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Zinc, Zink, A. Hot dip Zn-7Al alloy coating, A. Lamellar interfacial structure, B. Bend test, B. TEM observation, and C. Atmospheric corrosion

A new hot dip Zn-7Al alloy coating was performed on a structural steel by double coating of fine Zn and Zn-7 wt.% Al alloy, to prevent severe corrosion in coastal area. The alloy-coated steels were exposed to seaside, quasi-industrial, and rural districts to compare with conventional Zn coating. Double coating was significantly effective in preventing corrosion, particularly in a seaside. It was estimated from the exposure test for 10 years that the life of the Zn-7Al alloy-coated steel would be almost four times that of the Zn-coated steel in the seaside. A bending test showed that no exfoliation occurred at the interface between the coated alloy and substrate steel. TEM observation revealed that the excellent adhesiveness of the doubly coated fine Zn and Zn-7Al alloy to the steel substrate was due to formation of the interface region consisting of heterogeneous fine phase mixture of zinc, aluminium and iron.

Electronics, Electronique, 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), Accommodation réseau, Mismatch lattice, Acomodación red, Autoassemblage, Self assembly, Autoensamble, Autocontrôle, Self control, Autocontrol, Epitaxie phase solide, Solid-phase epitaxy, Fabrication microélectronique, Microelectronic fabrication, Fabricación microeléctrica, Faisceau électronique, Electron beam, Haz electrónico, Microscopie tunnel balayage, Scanning tunneling microscopy, Microscopía túnel barrido, Nanofil, Nanowires, Nettoyage surface, Surface cleaning, Limpieza superficie, Traitement surface, Surface treatment, Tratamiento superficie, Electron beam evaporator, Ersi2 nanowire, Growth direction, STM, Self-assembled nanowire, Si(001), Si(110), and Substrate orientation

In this paper, we describe the fabrication of erbium disilicide (ErSi2) nanowires on clean silicon surfaces by self-assembled epitaxial growth due to a lattice mismatch between ErSi2 and silicon substrate. As surface treatment and surface orientation were important for controlling the nanowire growth, we formed a clean surface of Si(001)2 x 1 and Si(1 10)1 x 1. Then, ErSi2 nanowires were formed on the silicon surface by solid phase epitaxial growth. The silicon surfaces and the nanowires were observed using ultrahigh vacuum scanning tunneling microscopy (UHV-STM). The length of the nanowires on the Si(001) surface ranged from a few 10 s of nm to a few 100 s of nm, and the growth occurred in the orthogonal two-way directions of Si[110] and Si[110]. Although the length of the nanowires on Si(110) was almost the same as that on Si(001), the growth occurred in the one-way direction of Si[110]. This result indicates that the growth direction of the self-assembled nanowires can be controlled by the Si surface orientation.

Electronics, Electronique, 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, Transistors, Caractéristique électrique, Electrical characteristic, Característica eléctrica, Couche active, Active layer, Capa activa, Couche superficielle, Surface layer, Capa superficial, Courant drain, Drain current, Corriente dren, Densité élevée, High density, Densidad elevada, Diffraction RX, X ray diffraction, Difracción RX, Effet surface, Surface effect, Efecto superficie, Evaluation performance, Performance evaluation, Evaluación prestación, Faisceau ionique, Ion beam, Haz iónico, Liaison disponible, Dangling bond, Enlace disponible, Microscopie force atomique, Atomic force microscopy, Microscopía fuerza atómica, Spectre photoélectron RX, X-ray photoelectron spectra, Traitement par plasma, Plasma assisted processing, Traitement surface, Surface treatment, Tratamiento superficie, Transistor couche mince, Thin film transistor, Transistor capa delgada, Electronique organique, Organic electronics, Electrónica orgánica, Ar ion beam, Argon, OTFTs, Organic thin film transistors, and Pentacene

The effects of surface treatment techniques of gate dielectric in organic thin film transistors were investigated to improve the device performances. Pentacene-based organic thin film transistors were fabricated on thermally grown SiO2 and Argon ion and O2 plasma treatment were performed onto SiO2 surface to investigate their effect onto surface cleaning and subsequent device performance. X-ray diffraction, X-ray photoelectron spectroscopy and atomic force microscopy analyses were performed to examine the status of gate dielectric and pentacene active layer after each surface treatment, which could change the electrical performances of devices. Argon ion treated device showed a mobility 2.5 times higher than the non-treated sample and its drain current on/off ratio increased by two orders of magnitude compared to the reference non-treated sample. O2 plasma treatment also improved the mobility, but degraded the on/off current ratio due to a high density of dangling bonds on the dielectric surface.

Chemical engineering, Génie chimique, Mechanical engineering, Génie mécanique, Mechanics acoustics, Mécanique et acoustique, Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Instruments, appareillage, composants et techniques communs à plusieurs branches de la physique et de l'astronomie, Instruments, apparatus, components and techniques common to several branches of physics and astronomy, Techniques, équipements et instruments mécaniques, Mechanical instruments, equipment and techniques, Systèmes et dispositifs micromécaniques, Micromechanical devices and systems, Sciences appliquees, Applied sciences, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Organes de machines, Machine components, Frottement, usure, lubrification, Friction, wear, lubrication, Adhérence, Adhesion, Adherencia, Autoassemblage, Self assembly, Autoensamble, Carbone adamantin, Diamond like carbon, Carbono adiamantino, Contact mécanique, Mechanical contact, Contacto mecánico, Couche monomoléculaire, Monolayer, Capa monomolecular, Dispositif microélectromécanique, Microelectromechanical device, Dispositivo microelectromecánico, Dispositif électromécanique, Electromechanical device, Dispositivo electromecánico, Echelle nanométrique, Nanometer scale, Epaisseur couche, Layer thickness, Espesor capa, Essai bille sur disque, Ball on disk testing, Ensayo de resistencia de bola sobre disco, Etude expérimentale, Experimental study, Estudio experimental, Frottement, Friction, Frotamiento, Microscopie force atomique, Atomic force microscopy, Microscopía fuerza atómica, Modification chimique, Chemical modification, Modificación química, Modèle milieu effectif, Effective medium model, Modelo medio efectivo, Moulage, Molding, Moldeo, Propriété surface, Surface properties, Propiedad superficie, Silicium, Silicon, Silicio, Système électromécanique, Electromechanical system, Sistema electromecánico, Traitement surface, Surface treatment, Tratamiento superficie, Tribologie, Tribology, Tribología, Usure, Wear, Desgaste, Micro, Nano, and Surface modification

Silicon (Si (100)) is a typically used material in micro/nano-scale devices, such as micro/nano-electromechanical systems (MEMS/NEMS). However, Si (100) does not have good tribological properties and hence its surface needs to be treated either chemically or topographically to enhance its tribological performance. In this paper, the micro/nano-frictional property of chemically and topographically modified Si (100) surfaces was studied. Chemically modified surfaces of Si (100) include coating of diamond-like carbon (DLC) films (two different thicknesses) and two self-assembled monolayers (SAMs). Topographically modified surfaces of Si (100) include nano-patterned poly(methyl methacrylate) (PMMA) on silicon wafer, fabricated by the process of a capillarity-directed soft lithographic technique. At the nano-scale, friction was measured using an atomic force microscope (AFM) and at the micro-scale it was measured using a ball-on-flat type micro-tribotester. Results showed that at both nano- and micro-scales, the modified Si (1 00) surfaces exhibited enhanced friction behavior when compared to bare Si (1 00) surfaces. The improved nano-friction behavior of the modified surfaces was attributed to their lower intrinsic adhesion and reduced real area of contact. In the case of nano-patterns, the physical (geometrical) reduction in contact area contributed in decreasing their friction. At micro-scale, wear was observed in the test samples (except in the case of SAMs), which influenced their friction behavior. Further, as a novel bio-mimetic approach for tribological application at micro-scale, the surface topography of natural leaves of Lotus and Colocasia were replicated by capillary force lithography using two different molding techniques. Interestingly, these bio-mimetically engineered surfaces exhibited superior micro-friction behavior. Indeed, this could be the first bio-mimetic approach of creating effective tribological materials by the direct replication of natural surfaces.

Chemical engineering, Génie chimique, Mechanical engineering, Génie mécanique, Mechanics acoustics, Mécanique et acoustique, Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Organes de machines, Machine components, Frottement, usure, lubrification, Friction, wear, lubrication, Ablation, Ablación, Alliage surface, Surface alloying, Aleación superficie, Alumine, Alumina, Alúmina, Coefficient frottement, Friction coefficient, Coeficiente roce, Céramique oxyde, Oxide ceramics, Cerámica óxido, Eau distillée, Distilled water, Agua destilada, Effet surface, Surface effect, Efecto superficie, Frottement glissement, Sliding friction, Frotamiento deslizamiento, Fusion laser, Laser fusion, Fusión láser, Fusion surface, Surface melting, Fusión superficie, Laser, Láser, Processus assisté laser, Laser assisted process, Proceso asistido láser, Rodage, Breaking in, Esmerilado, Texture, Textura, Traitement par laser, Laser assisted processing, Traitement surface, Surface treatment, Tratamiento superficie, Tribologie, Tribology, Tribología, Zircone, Zirconia, Zircona, Zirconium oxyde, Zirconium oxide, Zirconio óxido, Advanced ceramics, Laser microtexturing, Surface engineering, Surface modification, and Wear mechanism

Surface engineering was carried out on oxide ceramics (Al2O3-ZrO2, ZrO2) using two different laser-assisted processes: (i) modification of the edge layer of the ceramic by laser induced remelting and alloying and/or (ii) surface microtexturing by laser ablation. Crossed microchannels and elongated microdimples oriented parallel to each other were chosen as texture patterns and produced on flat specimens of the ceramics. Effects of these surface treatments on the tribological performance of steel/ceramic and ceramic/ceramic pairs were studied during reciprocating sliding in distilled water using a pellet-on-plate-geometry. The results showed a substantial reduction in friction and wear depending on the materials mated and the texture pattern used. With others, the running-in behaviour with high values of the friction coefficient of the sliding pairs could be considerably improved.

Chemical engineering, Génie chimique, Mechanical engineering, Génie mécanique, Mechanics acoustics, Mécanique et acoustique, Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Organes de machines, Machine components, Frottement, usure, lubrification, Friction, wear, lubrication, Alliage base fer, Iron base alloys, Coefficient frottement, Friction coefficient, Coeficiente roce, Epaisseur couche, Layer thickness, Espesor capa, Essai abrasion, Abrasion test, Ensayo abrasión, Essai usure, Wear test, Prueba al desgaste, Frittage, Sintering, Sinterización, Lubrifiant, Lubricant, Lubricante, Machine mouvement alternatif, Reciprocating movement machine, Máquina movimiento alterno, Manganèse phosphate, Manganese phosphate, Manganeso fosfato, Matériau fritté, Sintered material, Material sinterizado, Phosphatation, Phosphating, Fosfatación, Porosité, Porosity, Porosidad, Réaction chimique, Chemical reaction, Reacción química, Résistance abrasion, Abrasion resistance, Resistencia abrasión, Résistance usure, Wear resistance, Resistencia al desgaste, Traitement surface, Surface treatment, Tratamiento superficie, Tribologie, Tribology, Tribología, Usure abrasive, Abrasive wear, Desgaste abrasivo, Usure glissement, Sliding wear, Desgaste deslizamiento, Vapeur eau, Water vapor, Vapor agua, Vitesse usure, Wear rate, Velocidad desgaste, Friction, Sintered components, and Steam oxidation

Steam oxidation is an important industrial procedure for changing tribological properties, sealing porosity and improving aesthetics in sintered iron components. Manganese phosphate coatings are believed to have intrinsic lubricant properties and very low friction coefficients. In this work, after steam oxidation, sintered iron components were coated with manganese phosphate and their tribological behaviour was investigated. Components with two nominal film thicknesses were compared, either coated or uncoated with manganese phosphate. Their abrasion resistance was evaluated using micro abrasion wear tests. Reciprocating wear tests were used to study their sliding wear resistance. It was observed that phosphating of the oxidized samples resulted in an increase of the wear rate in both tests. Phosphating promoted a reduction of the oxide film thickness, probably due to the chemical conversion reaction with the oxide substrate. The reduction of wear resistance due to phosphating was associated with a reduction of oxide film thickness.

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, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de matériaux non métalliques, Nonmetallic coatings, Propriétés mécaniques. Rhéologie. Mécanique de la rupture. Tribologie, Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology, Fatigue, Chrome nitrure, Chromium nitride, Cromo nitruro, Chromnitrid, Contrainte résiduelle, Residual stress, Tensión residual, Eigenspannung, Dépôt physique phase vapeur, Physical vapor deposition, Deposición física fase vapor, Physikalisches Aufdampfen, Engrenage, Gear, Engranaje, Getriebe, Fatigue, Fatiga, Ermuedung, Modélisation, Modeling, Modelización, Méthode élément fini, Finite element method, Método elemento finito, Finite Element Methode, Propriété mécanique, Mechanical properties, Propiedad mecánica, Revêtement non métallique, Non metal coating, Revestimiento no metálico, Nichtmetallischer Ueberzug, Résistance fatigue, Fatigue strength, Resistencia fatiga, Dauerfestigkeit, Titane nitrure, Titanium nitride, Titanio nitruro, Titannitrid, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, CrN/TiN-PVD coating, FEM modelling, Residual stresses, and Steel/titanium spur gears

The aim of this work is to investigate into the possibility of enhancing the fatigue resistance of CrN-PVD coated components. In particular, PVD coated spur gears were tested and a numerical simulation of crack propagation was carried out. The coating layer microh-ardness and the residual stresses characterising the surface film were measured. The results obtained were then introduced in a numerical model for predicting the fatigue life procedure of coated gears used in gearboxes for automotive applications. The number of cycles necessary to reach specified crack depths in coated and uncoated steel and titanium spur gears was numerically determined. This represents a powerful tool to predict the fatigue life of coated gears. Benefits induced by the presence of the coating were pointed out. A sensitivity analysis was also carried out: Furthermore, the effects on the fatigue crack propagation of the residual stress gradient (evaluated by means of X-ray measurements), the elastic properties of the bulk material and coating were evaluated.