Improved corrosion resistance of extruded Mg-8Sn-1Zn-1Al alloy by microalloying with Mn

Abstract

We report that microalloying with Mn substantially enhances the corrosion resistance of extruded Mg-8Sn-1Zn-1Al alloy. The corrosion rates, measured by immersion tests in 0.6 M NaCl solution at 25 °C, were 4.37 and 246.72 mm y-1 for the quaternary alloys with and without 0.1 wt% Mn, respectively. The enhanced corrosion resistance due to Mn microalloying is attributed to reduced H2 evolution rate, attained by a change in the type of Al-containing intermetallic particles, which led to a reduction of the particles' electrochemical nobility.