Zinc coatings characteristics

Effluent Characteristics of Coil Coating on Zinc Coated Steel... 

It can be seen from Fig. 25 that the zinc coating obtained from solution Zn I is relativelly smooth, but without large flat and mutually parallel parts of the surface, which were characteristic of the previously observed copper surfaces (see Section 11.2(0 and Section 11.2(h). The surfaces of zinc coatings of thicknesses 20 and 60 pm were very similar to that of the zinc coating of thickness 25 pm and, consequently, the STM images of these zinc coatings are not presented. 

Traffic signs, streetlamp standards, metal barriers and fences, and many other items seen along roads are usually manufactured in galvanized steel (normal mild steel with a zinc coating). On such items it is common to see white corrosion (zinc oxide), characteristic of the oxidation of a zinc coating, often with spots of red rust also appearing that indicate that the steel base is being corroded. 

The corrosion product plays an important role in the corrosion resistance of zinc, particularly in aqueous and certain atmospheric environments (cf. low-alloy or weathering steels). In such cases, the corrosion kinetics may be parabolic in nature, the rate decreasing with time (cf. aluminum), an aspect that has been extensively investigated. Taylor and Tolley [184] have examined the characteristics of sprayed zinc coatings and concluded that the decrease in permeability was... 

FTIR spectroscopy was used for the analysis of ultrathin organic films on metals. FTIR in the reflection mode (IRRAS) was used to study the interaction of ultrathin films of dicyandiamide (hardener of most one-pack epoxy resins) with various substrates, model ones such as gold or zinc and industrial ones such as steel and zinc-coated steels. Pure zinc surfaces and, to a lesser extent, zinc-coated steels are shown to react with dicyandiamide after heating at 180 C, as evidenced by the frequency shift of the absorption band characteristic for nitrile groups. Some mechanically tested specimens are then analysed, after failure, by FTIR microspectrometry. The spectra obtained, corresponding to the fracture initiation zone which is about 100 micrometers in diameter, indicate the presence of an ultrathin layer of modified polymer still covering the substrate. 28 refs. 

The similar reflection and structural characteristics also showed the zinc coatings electrodeposited onto the zinc substrate [99], as well as those electrodeposited from acid sulfate solution with the addition of dextrin/furfural mixture [100]. 

The similarity of reflection and structural characteristics of the copper surfaces polished both mechanically and electrochemically, and the copper and zinc coatings electrodeposited with the corresponding brightening additives with those of silver mirror as the reference standard just enabled systematization of the conditions which metal surfaces must fulfill to be mirror bright. These conditions are ... 

Characteristics of coating Hot-dip galvanising A/etai spraying Plating Sherardising Zinc dust painting... 

A characteristic of the group (a) of resins is that they air-dry solely by solvent evaporation and remain permanently solvent soluble. This fact, combined with the need to use strong solvents, makes brush application very difficult, but sprayed coats can be applied at intervals of one hour. A full vinyl system such as (o) possesses excellent chemical and water resistance. Many members of group (o) have very poor adhesion to metal, and have therefore been exploited as strip lacquers for temporary protection. Excellent adhesion is, however, obtained by initial application of an etching primer the best known of such primers comprises polyvinyl butyral, zinc tetroxy-chromate and phosphoric acid. 

Aguilar, J. O. Gomez-Daza, O. Brito, L. A. Nair, M. T. S. Nair, P. K. 2005. Optical and mechanical characteristics of clear and solar control laminated glass using zinc sulphide and copper sulphide thin films. Surface Coatings Technol. 200 2557-2565. 

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