Corrosion behavior of diecast MgAlMnCaSi Magnesium Alloy

Abstract

The corrosion behavior of diecast MgAlMnCaSi (AMXS6020) magnesium alloy with superior flame-retardance and heat-resistance was systematically investigated and compared to diecast AZ91D magnesium alloy and ADC12 aluminum alloy by salt spray test, cyclic corrosion test, electrochemical experiment, scanning electron microscopy and energy dispersive X-ray spectroscopy. The results showed that AMXS6020 alloy had a higher corrosion resistance than AZ91D and ADC12 alloys. The superior corrosion resistance of AMXS6020 alloy was attributed to netlike eutectic structure consisting of (Al, Mg)2Ca and Mg, which could hinder the corrosion growth. The barrier effect of netlike (Al, Mg)2Ca phase structure on corrosion growth was also confirmed by potentiodynamic polarization.