耐腐蚀性能的提升有助于轻量化镁合金材料的进一步广泛应用。本文以 AZ41 和 AZ91 两种铸造镁合金为研究对象， 采用 XRD 、 OM 、 SEM 、 EPMA 等手段表征分析微观组织， 利用 EIS 测试了两种 Mg-Al-Zn 合金在 0.1 M 的NaCl 溶液中的耐蚀性能，结合宏微观腐蚀形貌探讨了微观组织对腐蚀行为的影响机制。研究结果表明，与 AZ41 合金相比，浸泡初期 AZ91 合金表面的氧化膜相对完整且化学稳定性更高，在腐蚀初期起到保护作用， AZ91 合金浸泡初期的耐蚀性能优于 AZ41 合金； 随浸泡时间延长， AZ41 合金中连续网状的过饱和 α-Mg+β-Mg 17 Al 12 共晶组织阻碍合金的腐蚀扩展；而 AZ91 合金中不连通的离异共晶 β-Mg 17 Al 12 相与 α-Mg 基体耦合，造成明显的局部腐蚀现象。

 The improved corrosion resistance contributes to the further application of lightweight magnesium alloys. In thispaper, the microstructure of the AZ41 and AZ91 alloys was analysed using various techniques such as XRD, OM, SEM, and EPMA. The corrosion morphology after immersion was observed. performance of the alloys was assessed in a 0.1 M NaCl solution using EIS measurement, and the corrosion morphology was characterized after immersion. The results show that the oxide film of the AZ91 alloy is relatively intact and more stable than that of AZ41 alloy at the early stages of immersion, resulting in better corrosion performance. However, with increasing immersion time, the connected α-Mg and β-Mg 17 Al 12 eutectic network inhibits corrosion propagation in the AZ41 alloy, while the disconnected eutectic β-Mg 17 Al 12 phase in the AZ91 alloy produces more micro-galvanic couples with the α-Mg matrix, leading to substantial localized corrosion.