Nanomer~® coatings containing flake-type zinc-manganese metal phosphate particles as corrosion protection additives for mild steel

摘要

Zinc phosphates and metal phosphates are commonly known to show interesting protection effect on steel against corrosion. The fundamental mechanism behind of the protection effect is still under discussion in literature. Barrier properties against diffusion, passivation of the steel surface, shielding and anti-cathodic disbonding abilitiy were reported in the past. In this study, we report the formation crystalline, anisotropic flake-type shaped zinc phosphates and mixed zinc-manganese phosphates as new corrosion protection pigments and their protection effect on mild steel. The corrosion protection ability was investigated by means of polarization and electrochemical impedance spectroscopy in dependence on the particles morphology and the molar ratio of zinc to manganese. Furthermore the particles were tried as active fillers in polymer matrix based Nanomer~® coatings.