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Electrochemical and localized corrosion behaviour of stainless steels in chloride solutions: a stocastic approach.
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Studio del comportamento a corrosione di laminati zincati sottoposti a deformazione meccanica
No full textFT-IR spectroscopic study of phosphate and chromate conversion coatings on aluminum
No full textPhosphate and chromate conversion coatings on aluminum have been studied by absorption-reflection Fourier Transform IR spectroscopy. Effects due to composition and temperature of the solutions used, as well as to time of immersion have been observed and discussed. In phosphate solutions aluminum hydroxides and oxyhydroxides containing acid phosphate ions are formed: they can undergo further evolution into zinc phosphate layers if the solution also contains zinc cations (e.g. commercial Bonderite). In chromate solutions, the initial steps are similar but the mechanism of further coating formation depends on the chemical composition of the solution. From acid chromate solutions, the coating contains aluminum/chromium oxyhydroxides, while from basic chromate solutions containing carbonate ions the main components are aluminum/chromium hydroxycarbonates. © 1982
Effect of powder painting procedures on the filiform corrosion of aluminium profiles
No full textIn this work, the filiform corrosion behaviour of powder painted aluminium profiles was studied, and the coating barrier properties together with adhesion to the substrate were analysed. Samples coated with a traditional painting procedure (one powder layer application followed by curing), and other samples coated using a special cycle to obtain wood grain effect were compared using accelerated filiform corrosion tests. Moreover, in order to better understand the degradation mechanisms of painted metal substrates, thermal stresses were applied to accelerate the natural weathering. The effects of the thermal aging were analysed by electrochemical impedance spectroscopy. Wood grain effect coatings showed to better resist, with respect to a traditional coating, to filiform corrosion when testing was performed following the DIN 65472 standard. On the contrary, electrochemical impedance measurements showed better barrier properties against water uptake for the traditional coating after thermal ageing. Different barrier properties were found to depend on the microstructure of the two coatings after curing. The traditional one has a homogeneous microstructure, with completely fused powder grains and very fine size pigments. On the contrary, wood grain effect coating possesses a "defective" microstructure with a widespread distribution of partially fused powders grains determining a dense network of grain boundaries, moreover coarser size pigments are present. This microstructure decreases the coating barrier properties, but also can determine a loss of plasticity and the coating under mechanical stress can crack modifying the filiform corrosion behaviour
Corrosion behaviour of electrogalvanized steel in sodium chloride and ammonium sulphate solutions; a study by E.I.S.
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