Short CommunicationRole of alloyed Y in improving the corrosion resistance of extruded Mg-Al-Ca-based alloy

- Effect of Y alloying on the corrosion of extruded Mg-Al-Ca-based alloy was investigated.
- Alloying with Y resulted in the formation of Al8Mn4Y and Al2Y instead of the nobler Al8Mn5.
- Corrosion resistance in 0.6 M NaCl solution was remarkably improved by alloying with Y.
- The role of the microstructural changes in the corrosion properties is discussed.

We report that alloying with Y remarkably enhances the corrosion resistance of extruded Mg-Al-Ca-based alloy. The corrosion rates, measured by immersion tests in 0.6 M NaCl solution at 25 °C, were 0.31 and 1.84 mm y−1 for the Mg-6Al-1Zn-0.5Ca-0.3Mn (wt.%) alloys with and without 0.25 wt.% Y, respectively. The improved corrosion resistance is mainly attributed to a change in the type of Al-containing intermetallic particles toward reducing their electrochemical nobility, resulting in reduced H2 evolution rate during corrosion.