This study investigated the corrosion behaviors of Mg-9Al-1Zn (Al-modified alloy) and Mg-5Gd-4Y-1Zn (RE-modified alloy) from microstructural and electrochemical perspectives. The heterogeneous grain structure and dislocation distribution readily promoted galvanic corrosion, thereby accelerating the degradation of the RE-modified alloy. Furthermore, the potential difference induced by the LPSO phase was greater than that caused by the β -Mg 17 Al 12 phase, leading to a highly non-uniform overall potential distribution and the pronounced micro-galvanic corrosion in the RE-modified alloy. Notably, compared to modification by Gd 2 O 3 /Y 2 O 3 , the formation of Al 2 O 3 /Al(OH) 3 was more effective in enhancing the stability of the protective film. Consequently, the Al-modified alloy demonstrated superior corrosion resistance relative to the RE-modified alloy.
Li et al. (Sat,) studied this question.