Effect of the Al–Si eutectic on the microstructure and corrosion behavior of the single-phase Mg alloy Mg–4Li

The influence of alloying with Al–Si eutectic on the microstructure and corrosion resistance of single-phase Mg–4Li was studied in this paper. The microstructure was characterized using an electron microscopy. The corrosion properties were measured by immersion tests and electrochemical impedance spectrum (EIS) measurements. Alloying with Al–Si eutectic caused the formation of Mg2Si and Mg–Al phase. The grain orientation of Mg–4Li was mainly composed of (0001) while the grain orientation of Mg–4Li–6(Al–Si) was mainly consisted of (10–10) and (11–20). Mg–4Li–6(Al–Si) shows worse corrosion resistance than Mg–4Li owing to the galvanic corrosion from the precipitates and texture change.