A Comparison Study on Corrosion Behavior of Zinc Phosphate and Potassium Zinc Phosphate Anticorrosive Pigments

I n this article, the effect of potassium on the phase formation and anticorrosion properties of zinc phosphate pigments has been investigated. The co-precipitation method was selected as synthesis method of potassium zinc phosphate pigment. Then the synthesized pigment was characterized by x-ray diffraction (XRD), Fourier transform infrared (FTIR) and Raman spectroscopy. Morphology of the powders was investigated with scanning electron microscopy (SEM). The inhibition efficiency of this pigment was compared to the commercial zinc phosphate pigment in a 3.5 % NaCl solution by means of electrochemical impedance spectroscopy (EIS) on mild steel specimens. The surface composition and morphology of mild steel specimens after exposure to the test solutions were examined by scanning electron microscopy- energy dispersive X-ray spectroscopy (SEM-EDX). The results indicate the better corrosion inhibitive performance of potassium zinc phosphate in comparison with the commercial zinc phosphate. Prog. Color Colorants Coat. 5(2012), 91-99. © Institute for Color Science and Technology.