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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 de métaux et d'alliages, Metallic coatings, Dépôt électrolytique, Electrodeposition, Depósito electrolítico, Elektroplattieren, Eau usée, Waste water, Agua residual, Abwasser, Hydrogène Sulfure, Hydrogen Sulfides, Hidrógeno Sulfuro, Hydrogène, Hydrogen, Hidrógeno, Wasserstoff, Microstructure, Microestructura, Mikrogefuege, Précipitation, Precipitation, Precipitación, Ausscheidung, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Séparation, Separation, Separación, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Electroplating Wastewater, Hydrogen Sulfide, Metal Sulfide, and Sulfuration

Experiments were conducted to investigate selective sulfuration of copper, zinc and nickel contained in a simulated plating wastewater using H2S as a sulfurating agent. The sulfuration of single solutions of copper, zinc and nickel, and mixed solutions of these metals with H2S was conducted in a bubble column reactor. As a result, it was found that heavy metals can be selectively precipitated from the mixed-metal plating wastewater at a pH value of 1.5 for copper, 4.5 for zinc and 6.7±0.2 for nickel. The purities of precipitates based on total amount of metal contained were 95.5%, 87.4% and 94.7% in the case of copper, zinc and nickel, respectively. When the results were compared with those obtained for the selective precipitation with Na2S, it was found that higher purities of metal sulfides were achieved with H2S. It was considered that local increases of pH resulting from an addition of alkaline sulfurating agent of Na2S were avoided in the case of H2S. Consequently, an undesirable co-precipitation of zinc and nickel sulfides at a pH value of 1.5 corresponding to copper selective precipitation was reduced. Similarly, the precipitation of nickel sulfide was partially avoided during the precipitation of zinc sulfide at a pH value of 4.5.

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, Dilatation thermique, Thermal expansion, Dilatación térmica, Thermische Ausdehnung, Dépôt électrolytique, Electrodeposition, Depósito electrolítico, Elektroplattieren, Expansion, Expansión, Nickel, Niquel, Propriété thermique, Thermal properties, Propiedad térmica, Thermische Eigenschaft, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Fe Content, Linear Expansion Coefficient, and Nickel-Iron Alloy Electrodeposits

We investigated thermal expansion properties of Ni-Fe alloy electrodeposits, which are anticipated for use as low thermal expansion materials. Thick and crack-free Ni-Fe alloy electrodeposits with 25 to 58mass% Fe contents were obtained from sulfate/ chloride electrolytes with additives, saccharin and malonic acid. The linear expansion coefficients of the electrodeposited Ni-Fe alloy pipes reduced with increasing Fe contents as melted alloys. For the Ni-58 mass%Fe alloy electrodeposits, the linear expansion coefficient exhibited 8.6 ×10-6/°C for the as-plated specimen and approximately 7×10-6/°C for the alloys annealed above 350°C.

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, Prédiction, Prediction, Predicción, Séquestrant, Complexing agent, Secuestrante, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Color Measurement, Empirical Equation, Gold Plating, Hydantoin Complexing Agent, and Numerical Analysis

Methods for prediction of gold plating characteristics by numerical analysis were investigated. The gold plating bath for the evaluation contains 5,5-dimethylhydantoin (DMH) as the complexing agent. HAuCl4 was used as the gold source, and phosphate salt was contained as a pH buffer. Thallium ion was added to refine the deposited grains. The concentration of Au ([Au]), the pH, and the temperature were manipulated to determine the composition and conditions of the plating bath. The appearance of gold films was evaluated by color measurement using the L*a*b* color system. This method of evaluation is advantageous in terms of quantification of the appearance. Values of the color measurement tended to change depending on the various compositions and conditions of the plating bath. The brightness of the color L* obtained as a result of the color measurement was analyzed numerically with a statistical technique. The following experimental formulas were established by the numerical analysis. L* (-) =K0{I -exp(-K1C)} -K2C K0( (-)= 73.9-2180 exp(-0.125 T) K1(M-1) =178 K2(M-1)=338-323 exp[-{(pH-7.18)/1.17}2] [C: [Au] (M=mol/dm3), T: temperature(°C) ].

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, Absorption, Absorción, Couche mince, Thin film, Capa fina, Duennschicht, Faisceau électronique, Electron beam, Haz electrónico, Elektronenstrahl, Propriété optique, Optical properties, Propiedad óptica, Optische Eigenschaft, Semiconducteur, Semiconductor materials, Semiconductor(material), Halbleiter, Silice, Silica, Sílice, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Electron Beam Deposition, GaSe, Layered Semiconductor, and Optical Absorption

Gallium selenide (GaSe) films, a layered semiconductor, were prepared on silica glass substrates by electron beam deposition at various substrate temperatures (Ts = R. T.∼500°C). The structure, growth and optical properties of the GaSe films were studied. The unit layer of GaSe films was grown toward the two directions on silica. It is revealed that the GaSe films deposited at R. T.∼300°C have amorphous structures, while those at 500°C have a polycrystalline structure with their c-axis perpendicular to the substrate plane. Also it was found that the crystalline structure of the film grown at 400°C is remarkably changed to become a c-axis parallel to the substrate plane and porous thin film. Furthermore, it was shown that the c-axis orientation of GaSe films could be controlled by the substrate temperature. The absorption edges of the GaSe films deposited at 500°C showed a direct allowed transition with an optical gap of Eg = 2.0 eV, which was in good agreement with those measured in single crystal GaSe.

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, Air, Aire, Luft, Indentation, Indentación, Microstructure, Microestructura, Mikrogefuege, Recuit, Annealing, Recocido, Gluehen, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Traitement thermique, Heat treatment, Tratamiento térmico, Waermebehandlung, : BCN Film, FT-IR, Nanoindentation, RF Sputter, and Thermal Annealing

Boron-Carbon-Nitrogen (BCN) films are deposited on Si (100) substrates by RF sputtering with a mixture of N2 and Ar gases using a target of graphite combined with semi-circled B4C. The compositional analysis is carried out by energy dispersive X-ray spectroscopy (EDX). The microstructure and mechanical properties are examined by fourier transformation infrared spectroscopy (FT-IR), atomic force microscopy (AFM) and nanoindentation measurements. The results of FT-IR show the presence of h-BN bonds and evidences in support of B-C, C-N, C=N, C=C and C≡N bonds. In additon, the C content of the films can be changed in the range of 13-45% according to the sample position. Hardness of the films is increased from 8 to 18 GPa with increasing C content. After thermal annealing at 600°C in air, h-BN bonds in the films are not affected significantly although the samples are oxidized. However, the hardness of the samples is abruptly reduced to 4 GPa for all samples. From AFM observation, it is assumed that the development of the void-like structure is responsible for the reduction in hardness.

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, Contrainte interne, Internal stress, Tensión interna, Contrainte traction, Tensile stress, Tensión traccíon, Zugspannung, Dépôt électrolytique, Electrodeposition, Depósito electrolítico, Elektroplattieren, Hydrogène, Hydrogen, Hidrógeno, Wasserstoff, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, 2-butyne-1,4-diol, Buoyancy, Hydrogenation, Tensile Stress, and Watts-type Bath

The hydrogenation of brightener 2-butyne-1, 4-diol at nickel electroplating from a Watts-type bath was investigated. The amount of hydrogen gas evolved during electroplating was in-situ evaluated quantitatively on the basis of buoyancy produced by hydrogen gas using an electric balance. The variation of the internal strain in nickel films plated with the addition of 2-butyne-1, 4-diol was measured using a resistance wire-type strain gauge placed on the reverse side of the copper substrate. The hydrogenation of 2-butyne-1,4-diol progressed easily on as-deposited nickel substrate compared with the commercial copper and nickel substrates, and the hydrogenation of 2-butyne-1,4-diol was always preferred to the formation of hydrogen gas during nickel electroplating. The 2-butyne-1, 4-diol adsorbed on as-deposited nickel electrode was hydrogenated catalytically by hydrogen co-deposited with nickel on the electrode. The hydrogenation of 2-butyne-1,4-diol might bring about the formation of internal tensile stress in the nickel deposits during electroplating.

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, Dissolution, Disolución, Aufloesung, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Acidic Electrolyzed Water, Hypochlorus acid, and Nickel

The dissolution rate and dissolution morphology of an electroplated nickel film in acidic electrolyzed water (AEW) of a sodium chloride aqueous solution and in a hydrochloric acid aqueous solution of the same pH were studied. As a result, it was found that the dissolution rate of the electroplated nickel layer in the AEW was about two times higher than that in the hydrochloric acid aqueous solution of the same pH. On the surface of the electroplated nickel film immersed in the AEW, the oxide layer was removed, and microscopic pits due to local dissolution were observed. The pit has a dish-like shape with a depth of less than 0. 5 μm, and its surface roughness decreased when compared to the one before soaking. On the other hand, as for the one immersed in the hydrochloric acid aqueous solution, no such phenomenon was observed, and its surface roughness increased. Moreover, when the AEW was heated to 40°C and sprayed, the dissolution of the electroplated nickel surface was promoted, the surface had a satin-like finish, and the possibility of etching was suggested.

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, Couche mince, Thin film, Capa fina, Duennschicht, Dépôt chimique, Chemical deposition, Depósito químico, Stromloses Beschichten, Dépôt électrolytique, Electrodeposition, Depósito electrolítico, Elektroplattieren, Multicouche, Multiple layer, Capa múltiple, Mehrfachschicht, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Electroless Plating, Electroplating, Multilayer, Nickel Phosphorus Alloy, and Single Bath

The nickel phosphorus alloy multilayer film was made by using both electroplating and electroless plating together from a single bath including phosphinic acid and nickel sulfate. The compositions of the nickel phosphorus alloy made by electroplating and by electroless plating from the same bath were different under suitable plating conditions. The multilayer film was made on a copper substrate by alternate continuous electroplating and electroless plating from that single bath. After bending that film with copper substrate in the liquid nitrogen to break the film and make the cross section, the film was examined. An SEM and EPMA examination of the cross section confirmed that the film was a multilayer of two kinds of nickel phosphorus alloys, and the phosphorus density of each layer was different. In addition, it was confirmed by XRD that the multilayer consisted of two types of layers, a crystalline one and an amorphous one. According to the observation of the structure of the cross section by SEM, it seems very likely that the strength of each layer was different.

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, Composé organique, Organic compounds, Compuesto orgánico, Organische Verbindung, Hyperfréquence, Microwave, Hiperfrecuencia, Mikrowelle, Pression atmosphérique, Atmospheric pressure, Presión atmosférica, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Atmospheric Pressure Toluene, Carbon Felt, Decomposition Behavior, and Microwave Discharge

We examined the decomposition of toluene by atmospheric pressure microwave discharge using carbon felt (CF) as an intriguing medium for sustaining plasma, and studied the decomposition behavior. The discharge was generated easily at 200 W microwave power using CF25which was thermally pretreated at 2500°C and had a relatively low electric resistance of 0.16Ωcm. The discharge was generated at the gap between each two pieces of CF, however, not generated at the inside of each CF. The temperature of the gap and the intensity of emission from discharging gaps were increased with seconds until they reached an equilibrium state in about 10 seconds. The XPS analysis revealed that the graphite structure of each carbon fiber making CF was maintained through the discharge, that is, the surface of carbon fiber was kept chemically unchanged without binding nitrogen and oxygen atoms. Toluene disappeared completely, and H2 was generated stoichiometrically by discharge in nitrogen or even in air atmosphere. Furthermore, in the case of the discharge in air with toluene, O2 disappeared, and CO and CΟ2 were generated. H2O, NOx and O3 were not detected. The reaction kinetic consideration revealed that the decomposition of Toluene followed the first-order reaction, the apparent decomposition rate constant of toluene was increased with the number of gaps between CFs in a reaction vessel, and the decomposition rate of toluene was independent of the concentration of O2.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Corrosion, Action des agents de corrosion, Corrosion environments, Acier non allié, Carbon steel, Acero no aliado, Unlegierter Stahl, Application, Aplicación, Anwendung, Corrosion, Corrosión, Korrosion, Gazoduc, Gas pipeline, Gasoducto, In situ, Industrie gazière, Gas industry, Industria del gas, Gasindustrie, Industrie pétrolière, Oil industry, Industria petrolera, Erdoelindustrie, Pipeline, Oleoducto, Procédé fabrication, Manufacturing process, Procedimiento fabricación, Fertigungsverfahren, Produit corrosion, Corrosion product, Producto corrosión, Korrosionsprodukt, Spectrométrie Raman, Raman spectrometry, Espectrometría Raman, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Corrosion Product, In-situ Analysis, Laser Raman Spectroscopy, Polarization, and Steel for Pipeline

The change in the chemical composition of the corrosion product on steel can be identified with in-situ Raman spectroscopy while the steel is polarized in a solution. In this paper, we tried to clarify the corrosion process of the steel for gas pipelines. γ-FeOOH and Fe3Ο4 were detected with the Raman spectra measured in the 100 mg/dm3Cl- solution holding at -0.3 V vs.Ag/AgCl. The coexistence of γ-FeOOH and Fe3O4 was confirmed from the Raman spectrum measured in the corrosion test. It is considered that Fe3O4 was formed via the reduction as follows: Fe2++8FeOOH+2e- → 3 Fe3O4+4H2O In the early stage of corrosion, γ-FeOOH was detected from Raman spectra measured in the 1000mg/dm3HCO3-solution holding at 0.5 V vs. Ag/AgCl. However, the peak of γ-FeOOH disappeared from the Raman spectra measured in the corrosion test after the middle stage of corrosion. It is conceivable that the γ-FeOOH disappeared or that the surface was covered with corrosion products inert to Raman measurement. We were able to investigate the corrosion process of the steel for gas pipelines with in-situ Raman spectroscopy while it was polarized in a solution.

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, Chromique acide, Chromic acid, Crómico ácido, Chromsaeure, Dépôt chimique, Chemical deposition, Depósito químico, Stromloses Beschichten, Nickelage, Nickel plating, Niquelado, Vernickeln, Prétraitement, Pretreatment, Pretratamiento, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, ASA Resin, Electroless Plating, Environment-Friendly, and Ozonated Water

In view of environmental concerns, ozonated water treatment was studied as a replacement for conventional chromic acid etching of plating on ASA Resin. Ozonated water treatment achieves favorable adhesion without roughening the plastic's surface. Chemical analysis and cross-sectional observations show the formation of polar groups on the surface of the treated resin. Catalytic palladium particles are dispersed and adsorbed into the treated resin surface layer after the catalyzing step. Nickel ions penetrate and scatter into the treated resin layer during electroless nickel plating. These observations prove that favorable adhesion can be attributed to the formation of a nanoscale reformed layer, which is completely different from the conventional anchor effect produced using chromic acid etching.

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, Aluminium, Aluminio, Anodisation, Anodizing, Anodización, Elektrolytisches Oxidieren, Argent, Silver, Plata, Silber, Corrosion électrochimique, Electrochemical corrosion, Corrosión electroquímica, Elektrochemische Korrosion, Couche oxyde, Oxide layer, Capa óxido, Oxidschicht, Dépôt électrolytique, Electrodeposition, Depósito electrolítico, Elektroplattieren, Oxydation, Oxidation, Oxidación, Oxyde anodique, Anodic oxide, Oxido anódico, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Anodized Aluminum Film, AuAg Alloy, Nanowires, and Surface Plasmon

AuAg alloy nanowires in the geometrically anisotropic pores of the aluminum anodic oxidation films with a mean diameter of 10 nm and depth of 10 μm were successfully prepared by the electrodeposition of gold and silver under the bath voltage of 6V AC in a cyanide-free bath (Ag2SO4-HAuBr4-(NH4)2S2O3). The aspect ratio of the alloy nanowires was controlled by changing the electrodeposition time. The maximum position of absorption band due to the transverse surface plasmon resonances of AuAg alloy nanowires shifts to a longer wavelength with an increase of the composition of Au. The color and shading of the anodized aluminum deposited with alloy nanowires were simply tuned in a wide range.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Propriétés mécaniques. Rhéologie. Mécanique de la rupture. Tribologie, Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology, Fatigue, Rupture, Fractures, Acier outil, Tool steel, Acero herramienta, Werkzeugstahl, Acier rapide, High speed tool steel, Acero rápido, Schnellarbeitsstahl, Diamant synthétique, Synthetic diamond, Diamante sintético, Fatigue surface, Surface fatigue, Fatiga superficial, Oberflaechenzerruettung, Fractographie, Fractography, Fractografía, Fraktographie, Propriété mécanique, Mechanical properties, Propiedad mecánica, Rupture, Ruptura, Bruch, Structure diamant, Diamond structure, Estructura diamante, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Traitement thermique, Heat treatment, Tratamiento térmico, Waermebehandlung, Fatigue Reliability, Heat Treatment Condition, and Hybrid DLC

A method for fatigue reliability evaluation of Hybrid DLC to ensure safe design is proposed. This concept represents a major contribution to the fatigue reliability design method for surface modification components, namely The influence of surface modification processing on materials with internal failures. The fatigue reliability of high-speed tool steel SKH-51, coated with Hybrid DLC, is described. Hybrid DLC is a compound film process that produces a DLC film by P-CVD on a PVD system TiN hard film. This material follows the weakest link model. The variation in the inclusion leading to internal destruction was examined statistically. Convergence of the variation produced in the S-N diagram was tried. The influence of coating processing on fatigue fracture mechanism was considered. In particular attention was paid to change due to the heat treatment history of the base material. The industrial significansce of the acquired knowledge was examined.

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, Irradiation UV, Ultraviolet irradiation, Irradiación UV, Reformage, Reforming, Reformación, Titane oxyde, Titanium oxide, Titanio óxido, Titanoxid, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, ABS Resin, Photocatalyst, and Ultra Violet Irradiation

ABS resin has been widely applied as a plating substrate for plastics in applications such as the parts of vehicles and electrical devices. Hexavalent chromium has been applied as an etchant of plating on ABS resin. However, it is required to eliminate hexavalent chromium from the pretreatment process, since the prohibition of these treatments was determined by the EU directive on the End of Life Vehicles (ELV) from July, 2007. Therefore, alternative etching without hexavalent chromium has been investigated by using ultra violet irradiation (UV) and titanium oxide (TiO2) as a photocatalyst. We already achieved adhesion with the strength of about 1.0 kNm-1 between ABS resin and deposited metal without hexavalent chromic acid etching. In this study, the mechanism of adhesion strength improvement with photocatalysts has been investigated using ABS specimens and rubber related ABS resin. As the results, the 1, 2-polybutadiene distributed in the AS matrix was preferentially reformed and induced hydrophilicity on the reformed surface with the remaining network structure by cross-linking. In addition, we found that the reformed layer was composed a few μm thick and the catalyst penetrated into 30-40 nm from the surface. It was concluded that the good adhesion strength between the deposited metal and resin was derived from the nano-anchor effect by the deposition of metal from the inside of 30-40nm of reformed resin.

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, Anisotropie magnétique, Magnetic anisotropy, Anisotropía magnética, Magnetische Anisotropie, Cobalt, Cobalto, Couche interfaciale, Interfacial layer, Capa interfacial, Couche mince, Thin film, Capa fina, Duennschicht, Dépôt électrolytique, Electrodeposition, Depósito electrolítico, Elektroplattieren, Multicouche, Multiple layer, Capa múltiple, Mehrfachschicht, Palladium, Paladio, Propriété magnétique, Magnetic properties, Propiedad magnética, Magnetische Eigenschaft, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Co/Pd Multi-layered Films, Nano-ordered Plating, Perpendicular Magnetic Anisotropy, Tin Underlayer, and Underlayer Films

We prepared electroplated nano-ordered multilayered Co/Pd films on an electropolished polycrystalline copper substrate using an automatic plating machine and confirmed that the films show a remanent perpendicular magnetic anisotropy which depends on the Co film thickness. The effect of underlayer films using Pd, Sn, Pt, Rh films between Co/Pd films and the copper substrate was studied. When Sn film was used as the underlayer film, higher magnetic properties than when using other underlayers, i. e., SQR=0.79, coercive force=680 Oe, were obtained.

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, Dépôt électrolytique, Electrodeposition, Depósito electrolítico, Elektroplattieren, Eau usée, Waste water, Agua residual, Abwasser, Filtration, Filtración, Microstructure, Microestructura, Mikrogefuege, Précipitation, Precipitation, Precipitación, Ausscheidung, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Electroplating Wastewater, Filtration Characteristics, Metal Sulfide, and Sodium Polysulfides

Selective recovery of copper, zinc and nickel from electroplating wastewater was studied by investigating the sulfuration behaviors of these metal components and the filtration characteristics of the metal sulfides produced. As model metal solutions, CuSO4, ZnSO4 and NiSO4 aqueous solutions of 100 mg/dm3 initial concentrations were employed. Three kinds of sulfurating agents : sodium sulfide (Na2S), sodium disulfide (Na2S2) and sodium tetrasulfide (Na2S4) of 6.8 × 10-2mol/dm3 were used. For selective sulfuration of CuSO4, ZnSO4 and NiSO4, the sulfurating agent was added to the metal solutions, adjusting the pH of these solutions at pH=1.4-1.5, 2.4-2.5 and 5.5-6.0, respectively. As a result, it was found that Na2S was most effective for selective sulfuration of copper, zinc and nickel. The sulfuration behaviors of copper, zinc and nickel in electroplating wastewater were almost the same as those in model solutions. Furthermore, the filtration characteristics such as the average specific filtration resistance and the compressibility coefficients of the metal sulfide produced with different sulfurating agents were measured. It was recognized that the average specific filtration resistance of the metal sulfides produced with different sulfurating agents was different. It was also found that the compressibility coefficient of the metal sulfides was lower than that of metal hydroxide. The compressibility coefficient of the metal sulfides decreased in the order of Na2S, Na2S2 and Na2S4.

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, Etat surface, Surface conditions, Estado superficie, Oberflaechenzustand, Activation, Activación, Adhérence, Adhesion, Adherencia, Adhaesion, Electroformage, Electroforming, Electroformación, Elektroformgeben, Nickel, Niquel, Rugosité, Roughness, Rugosidad, Rauhigkeit, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, AES Analysis, Nickel Electroforming, Peeling Properties, Potassium Dichromate, and XPS Analysis

The properties and mechanism of peeling on nickel electroforming were investigated changing the activation treatment, the surface roughness of substrate and varying the treatment conditions (concentration, time, and temperature) of potassium dichromate solution. The results obtained are : the peeling force increases with an increse of the arithmetrical mean roughness (Ra) when the activation treatment is carried out. That is, the peeling force is proportional to Ra. Activating the surface of the substrate with an acid such as sulfuric acid reduces the peeling force below about one-half. The content (at%) of chromium in the film increases with an increse of the concentration of potassium dichromate and the treatment time. The peeling forces decrease with an increse of the content of chromium and the treatment time. On the other hand, the treatment temperature does not affect the thickness and the content of chromium in chromate film. On the basis of the results, it may be concluded that the important parameters affecting the peeling properties are as follows : firstly the roughness of surface, secondly the activation, and thirdly the conditions of chromate treatment. From measuring the thickness and content of chromate film on a substrate by AES analysis, it was found that the peeling occurs in the layer of chromate film.

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, Acier inoxydable, Stainless steel, Acero inoxidable, Nichtrostender Stahl, Fibre métal, Metal fiber, Fibra metálica, Metallfaser, Ozone, Ozono, Ozon, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Gaseous Ozone Treatment, Nonwoven Fabric of Stainless Steel Fiber, Regeneration, Sterilization of Fungi, and Surface Modification

Highly-concentrated gaseous ozone of 15vol% was produced from an ozone-oxygen mixture (5vol%), generated from a pure oxygen-fed discharge ozonizer, by using silica-gel as an adsorbent. The nonwoven fabrics of stainless steel fiber were treated with 15vol% gaseous ozone for 60min. As a result of the ozone treatment, the total amount of metal ions dissolved from the ozone-treated stainless steel fiber during immersion in pure water decreased by 70% compared with that from non-ozone-treated stainless steel fiber. X-ray photoelectron spectroscopic analysis showed that Fe and O were enriched by 1.6-fold in the outermost surfaces of the stainless steel fiber after ozone treatment. It was suggested that the formation of a highly resistant Fe-oxide film was responsible for the improvement of corrosion resistance. Pretreatment of protein-fouled nonwoven fabrics of stainless steel fiber by 15vol% gaseous ozone for 30 min markedly facilitated the removal of protein during subsequent rinsing and caustic alkali cleaning through the decomposition of protein molecules by O3 oxidation. In addition, fungi, Penicillium chrysogenum and Alternaria altenata, were completely sterilized by treatment with 15vol% gaseous ozone for 1 min. The results indicated that surface modification, cleaning, and sterilization of nonwoven fabric of stainless steel fiber could be performed by its exposure to 15vol% gaseous ozone.

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, Cuivre, Copper, Cobre, Kupfer, Etain, Tin, Estaño, Zinn, Microstructure, Microestructura, Mikrogefuege, Mécanisme croissance, Growth mechanism, Mecanismo crecimiento, Wachstumsmechanismus, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Copper Substrate, Matt Tin, Nodule, Tin Whisker, and and Structure of Deposits

In order to study the relation between whisker growth and the structures of deposits with respect to matt Sn deposits plated on Cu substrates, the dimensions of the grains of the deposits and those of the whiskers and/or nodules (whiskers/nodules) were determined as a function of the thickness of the deposits. Furthermore, the extruded mass per unit area attributed to the whisker/nodule growth has been estimated from the above data and the number density of the whiskers/nodules. It has been found that (1) : the matt Sn deposits are formed during electrodeposition in accordance with the mechanism known as geometrical selection : the average grain size is proportional to the root of the thickness of the deposits, (2) the whisker growth originates from the grains situated on the surface of the deposit the whiskers are considered to be the outward protrusions of the grains, and (3) : the whisker growth can take place when the radius of the grain, consequently of the whisker, is larger than a critical radius, r*. and which was found to be 0.34 < r*<0.43 μm. It has also been found that the extruded mass per unit area was constant regardless of the thickness when the thickness of the deposits was more than 2 μm. On the other hand, it has been shown that, in thick deposits, the grain growth, which is expected to reduce the grain-boundary free energy and the strain energy included in the deposits, can easily take place. These suggest that the nature of the excessive energy that drives the whisker/ nodule growth is different from the grain-boundary free energy or the strain energy.

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, Electrode, Electrodes, Electrodo, Elektrode, Microusinage, Micromachining, Micromaquinado, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Usinage électrochimique, Electrochemical machining, Mecanizado electroquímico, Elektrochemisches Bearbeiten, Electrochemical Process, Glass Microchannel, MEMS, Microelectrode, and μTAS

In order to implement electrochemical processes (e.g., detection or synthesis) on a chip-based system, micromachining techniques for a glass microchip with fully integrated electrodes have been developed. Pt/Ti microelectrodes were successfully patterned on the curved surface of a glass microchannel, which was etched in a HF solution using polysilicon thin film as an etch mask, by means of a lift-off method using a positive thick photoresist. In this process, the photoresist must be exposed with a single wavelength (g line) selected from a high-pressure mercury lamp in order to obtain its microstructure with excellent edge quality and vertical sidewalls. In addition, although fusion bonding cannot be used for microchips with lead patterns in the interface between a pair of glass substrates, a glass cover plate can be bonded to a glass substrate with lead patterns embedded in the space formed on its surface by buffered HF (BHF) etching. The resulting bonded area ratio was estimated to be approximately the same as that for glass-to-glass bonding.