Phytic acid conversion coating on AZ31B magnesium alloy

Author： Gao H F Zhang S T Liu C L Xu J Q Li J

ISSN： 1743-2944

Source： Surface Engineering, Vol.28, Iss.5, 2012-06, pp. : 387-392

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

A phytic acid conversion coating was formed on AZ31B magnesium alloy and its optimum processing parameters were also investigated by hydrogen evolution method in this work. The surface morphology, element compositions and corrosion resistance of coating were examined by atomic force microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy electrochemical measurements, and hydrogen evolution method. The results show that the optimum processing parameters of coating are pH value of 2, treating time of 40 min, treating temperature of 40°C and solution concentration of 4 g L⁻¹. The conversion coating, composed of O, C, P, Mg, Al and Zn, consists of two layers, the compact inner layer and the outer layer with some fine cracks. The treated sample has better corrosion resistance and protection characteristic than the untreated sample.