Corrosion and chemical behavior of Mg97Zn1Y2-1wt.%SiC under different corrosion solutions

Abstract

To explore the corrosion properties of magnesium alloys, the chemical behavior of a high strength Mg97Zn1Y2-1wt.%SiC alloy in different corrosion environments was studied. Three solutions of 0.2 mol·L-1 NaCl, Na2SO4 and NaNO3 were selected as corrosion solutions. The microstructures, corrosion rate, corrosion potential, and mechanism were investigated qualitatively and quantitatively by optical microscopy (OM), scanning electron microscopy (SEM), immersion testing experiment, and electrochemical test. Microstructure observation shows that the Mg97Zn1Y2-1wt.%SiC alloy is composed of α-Mg matrix, LPSO (Mg12ZnY) phase and SiC phase. The hydrogen evolution and electrochemical test results reflect that the Mg97Zn1Y2-1wt.%SiC in 0.2 mol·L-1 NaCl solution has the fastest corrosion rate, followed by Na2SO4 and NaNO3 solutions, and that the charge-transfer resistance presents the contrary trend and decreases in turn.

Keywords

• mg97zn1y2-1wt.%sic; corrosion rate; corrosion morphology; corrosion mechanism