A simple method for the preparation of magnesium phosphate conversion coatings on a AZ31 magnesium alloy with improved corrosion resistance

Abstract

A simple method has been proposed for the preparation of magnesium phosphate conversion coating on a magnesium alloy (AZ31) to achieve protection against fast degradation in an implant environment. The conversion coating consists of an interior layer of dense newberyite and an outer layer of struvite and newberyite. Polarization curves and electrochemical impedance spectroscopy (EIS) were employed to evaluate the corrosion behavior of the coatings in a simulated body fluid (SBF) solution. The corrosion resistance of the magnesium phosphate coated AZ31 magnesium alloy increased about 20 times compared with that of the AZ31 magnesium alloy.