Microstructure and corrosion behavior of Al–10%Mg2Si cast alloy after heat treatment.

The microstructure and corrosion behavior of Al–10%Mg 2 Si alloy after heat treatment are investigated. For Al–10%Mg 2 Si in 3.5 wt.% NaCl solution, corrosion of α -Al phase initiates in (Al + Mg 2 Si) binary eutectic zones with electrochemical polarity change of Mg 2 Si phase, and expands along the eutectic Mg 2 Si precipitates. After heat treatment, eutectic Mg 2 Si transforms from long flakes and rods to short fibers, disks and spheroidized particles. The transformation of eutectic Mg 2 Si phase suppresses the rapid expansion of corrosion pits, which leads to enhancing the corrosion resistance of Al–10%Mg 2 Si alloy. [ABSTRACT FROM AUTHOR]