Mechanism of chemical deposition of nickel-boron coatings in tartrate-glycine solutions

The effect of glycine additive on the deposition of nickel-boron coatings from tartrate-glycine solutions was studied.     

Comparison of the reactivities of main boron-containing additives used in electrodeposition of nickel-boron coatings

Reactivities of the main boron-containing additives used in electrodeposition of nickel-boron coatings were compared by measuring the rate of boron incorporation into a nickel coating and the effective activation energy.     

Corrosion properties of electroplated coatings of iron-group metals

Comparative corrosion resistance of cobalt alloys with molybdenum and phosphorus was studied. It is shown that the corrosion parameters of the alloys depend on the composition and structure of coatings. It is demonstrated that the introduction of phosphorus into an alloy positively affects its corrosion resistance.     

Crystalline roughness as a morphological characteristic of the surface of electroplated silver coatings

Structure and morphology of electroplated silver coatings deposited from a borate-phosphate-carbonate electrolyte were studied in relation to the current density and temperature. Average values of the crystalline roughness were determined.     

Specific features of cathodic deposition of nickel-boron coatings from a sulfuric acid electrolyte with addition of polyhedral borates

Specific features of the cathodic deposition of nickel-boron coatings from a sulfuric acid electrolyte with addition of polyhedral borates were considered.     

The unusual nanostructure of nickel-boron catalyst

A highly unusual nanostructure of the nickel-boron particulate material, initially synthesised in the 1950s and well known to be an exceedingly active hydrogenation catalyst, has been identified for the first time.     

Production of composite electroplated nickel-fullerene C<Subscript>60</Subscript> coatings

Kinetic relationships of the deposition of composite electroplated coatings based on nickel with a disperse phase of C₆₀ fullerene were studied. The composition of the coatings was determined by secondary-ion mass spectrometry.     

Magnetostriction in electroplated CoFe alloys

The phenomenon of magnetostriction can wirelessly couple external magnetic fields to generate structural motion. This is an attractive solution for remote delivery of power to microactuators in constrained environments. This study discusses the magnetostriction of electrosynthesized CoFe thin film microactuators. Electrodeposition is commonly employed for the fabrication of metallic thin films, however the magnetostriction of such films has been rarely investigated. In particular, the magnetostrictive behavior of electroplated CoFe films is poorly understood, despite the high magnetostriction capabilities of CoFe alloys. In this work, uniformly thick and smooth Co_0.65Fe_0.35 thin films were electrochemically grown on commercially available micron-scale cantilevers. The CoFe thin films were characterized for their morphology, composition, crystal structure, and magnetic properties. The AC magnetostrictive response of the cantilevers was measured interferometrically and the actuator exhibited a maximum expected displacement of 86 nm.     

Wear resistance of electrolytic nickel-boron alloy deposited from a chloride electrolyte

Dependence of the wear resistance of an electrolytic nickel-boron alloy deposited from a chloride electrolyte on the alloy composition, thermal treatment temperature, and specific load on friction surfaces was studied.     

Deposition of thin electroplated Cd-Se layers

Cadmium-selenium alloys were electrodeposited from a sulfuric acid electrolyte. The effect of the H₂SeO₃, CdSO₄, and sulfuric acid concentrations, current density, and temperature on the composition and quality of cathode deposits was studied.     

Rf‐GDOES analysis of composite metal/ceramic electroplated coatings with nano‐ to microceramic particles' size: issues in plasma sputtering of Ni/micro‐SiC coatings

Ni matrix composite coatings reinforced with nano‐ and microceramic particles were analyzed by radio frequency glow discharge optical emission spectrometry (Rf‐GDOES). An interesting phenomenon related to the sputtering and excitation modes of this technique was observed. During plasma sputtering with Rf‐GDOES, the micro‐SiC particles were detached from metal matrix and did not contribute to the analytical signals. The same was not found in composite coatings containing nanoceramic particles. This anomalous behavior was confirmed by atomic force microscopy (AFM) investigation and scanning electron microscope (SEM) observations into Rf‐GDOES craters that showed the presence of residual non‐sputtered microparticles. Various attempts were done in order to minimize this problem, mainly by varying the analysis parameters of the used instrumentation, but without any relevant success. Some suggestions were then proposed for explaining the observed phenomenon, moreover possible solutions (e.g. by using a strong magnetic field or changing plasma gas to be more energetic) are discussed. Copyright © 2011 John Wiley & Sons, Ltd.     

Structure and properties of thin-film polyguanidine-based composite coatings deposited from the gas phase

Morphological features and structure of thin-film composite coatings containing polyhexamethylene-guanidines and polyurethanes and prepared from volatile products of electron-beam dispersion of these polymers were studied.     

Segregation of organic impurities in thin electroplated Cu metallizations

This article presents investigations regarding the incorporation of organic impurities in thin electroplated Cu metallizations. RF-GD-OES (radio frequency glow discharge optical emission spectrometry) was used for detection of C and H as indicators for incorporated hydrocarbon molecules. The presented results indicate a fragmentation of incorporated hydrocarbons and their constrict segregation near the Cu surface. The bilateral relationship between incorporated organic impurities and intrinsic stress behavior is associated with the Gorky effect.     

Analysis of the environmental parameters for aircraft coatings

Temperature, UV radiation and pollutants play a major role in the degradation of aircraft coatings. The UV radiation at flying altitude is more intense than at ground level. An analysis of the radiation spectrum was used to choose the appropriate lamp type for artificial weathering in the laboratory. For the pollutants we examined the fact that the service life of aircraft coatings was considerably reduced in the years following the eruption of the volcano Pinatubo. It is shown that sulphuric-acid-aerosol droplets dispersed in the stratosphere were the main cause for that damage.     

Characterization of lattice disorder in the low-temperature phase of irradiated PTFE by vibrational spectroscopy

In an effort to elucidate the structure of the low-temperature phase of PTFE, a spectroscopic study of the effect of progressive irradiation on the low-frequency infrared spectrum was undertaken. Previous infrared and Raman measurements indicated that irradiation of PTFE decreases its crystalline content, resulting in a lowering of the 19°C phase transition temperature due to the introduction of disorder and defect structures into the lattice by chain scission. Far-infrared studies of virgin and irradiated PTFE at liquid nitrogen temperatures show that the medium to strong bands at 45, 54, 58, and 71 cm^?1, attributed to lattice vibrations, decrease in intensity as the crystalline content decreases. These findings support the assignment of these bands to intermolecular vibrations of the crystalline lattice and are an indication of the presence of more than one molecule in the crystallographic unit cell.     

Composite electrochemical coatings with a carbon-containing dispersed phase or polytetrafluoroethylene

Composite electrochemical coatings based on nickel, zinc, and chromium were studied. The dispersed phase of these coatings is constituted by graphite, diamond, and polytetrafluoroethylene produced from wastes formed in manufacture of fluoroplastic and ultradispersed diamond produced from industrial waste. The conditions in which high-quality coatings with best characteristics, such as microhardness and corrosion resistance, were determined. The wear resistance was additionally found for the chromium-diamond coating.     

On the deformation induced order–disorder transitions in the crystalline phase of polyamide 6

The present paper deals with the mechanically induced structural changes in polyamide 6 with initial α or γ crystal phases. By combining Wide Angle X-ray Scattering with FTIR spectroscopy measurements, order–disorder transitions have been clearly evidenced at 70 °C in both cases. The origin of this phenomenon is ascribed to structural defects involved in plastic deformation. By contrast, at 150 °C, no major transformation is revealed in α phase, whereas when starting from γ crystals, a γ−α transition is clearly evidenced. The central role of intracrystalline molecular mobilities is pointed out to account for the observed behaviours as a function of temperature.     

Morphology of polytetrafluoroethylene coatings formed from the active gas phase and its thermal modification

Changes in the morphology and surface energy of polytetrafluoroethylene coatings in the course of their growth and after annealing were determined.     

Thick silica gel coatings on methylsilsesquioxane monoliths using anisotropic phase separation

Silica gel coatings on methyltrimethoxysilane (MTMS)-derived monoliths have been studied using wetting transition. Wetting transition is observed in a small confined space, where a coating solution phase-separates into a well-coarsened dimension, making all the phase-separating polymerizing silica phase dynamically flow onto the existing surface of a mold. Bulk coating experiments have shown reductions of both macropore volume and diameter due to the coated layer. Comparing HPLC efficiencies of the coated monolith with those of the non-coated MTMS monolith revealed that the retention factors drastically increased in both normal- and reversed-phase modes. This is attributed to the existence of considerable amounts of accessible micropores left inside the coated layer, where analyte molecules travel and adsorb for a considerable period of time.     

Determination of carbon in electroplated gold layers by deuteron activation analysis

Carbon is determined in gold layers electroplated on brass, by deuteron activatin analysis using the¹²C/d, n/¹³N reaction. The results range from 2 to 1300 g.g^–1 and the relative standard deviation from 0.9 to 13%. It is quantitatively shown that the hardness of the gold increases with the carbon concentration and that the carbon concentration decreases with increasing plating temperature and increases to a certain limit with the plating current density.