Protective coating of zinc and zinc alloys for industrial applications

摘要

Zinc and zinc-based electrogalvanized coatings have attracted remarkable interest because of the increasing demand for layers with better corrosion resistance. A new approach for improvement of the protective ability is the incorporation in the metal matrix of polymeric nanoparticles. The latter affect positively the protective properties of the nanocomposite coatings and result in increasing of their corrosion resistance in 5% NaCl solution compared to the pure zinc and Zn-Co. The zinc coating process using the developed saturating mixtures excludes the phases of evaporation and condensation and the process is defined as hard-phase zinc coating. The hard phase zinc coating decreases the coating time 1, 5-2 times and powder dissipation with 20-25% compared to vapor-phase zinc coating. It does not require cooling the product together with the powder at the end of the process. The hard phase zinc coating has a high degree of automation and provides uniform coating of long-sized products and allows creating high-performing equipment. The prevention of the superficial roughness, during the hard phase zinc coating, leads to higher adhesion of varnishing coverings on the zinc-coated surface in comparison with vapor-phase zinc-coating.