Abstract The corrosion behavior and mechanism of as-cast and as-extruded Mg-Zn-Gd-Zr alloys with specific ternary phases are investigated using scanning electron microscope (SEM), scanning Kelvin probe force microscope (SKPFM), immersion and electrochemical tests. Lamellar X-Mg12GdZn, net-like W-Mg3Gd2Zn3 and strip-like I-Mg3Zn6Gd phases form successively. The eutectic W-phase owns the highest potential difference of 120 mV with Mg matrix, accelerating micro-galvanic corrosion. Continuously distributed and undersized I-phase leads to uniform corrosion. The as-extruded Mg-3Zn-11Gd-0.6 Zr alloy exhibits superior corrosion resistance, due to the relatively low potential difference between X-phase and matrix, the corrosion barrier effect and typical {0002} texture components.

中文翻译：

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特定第二相对Mg-Zn-Gd-Zr合金腐蚀行为的影响

摘要 采用扫描电子显微镜（SEM）、扫描开尔文探针力显微镜（SKPFM）、浸泡和电化学测试研究了具有特定三元相的铸态和挤压态Mg-Zn-Gd-Zr合金的腐蚀行为和机理。层状X-Mg12GdZn、网状W-Mg3Gd2Zn3和条状I-Mg3Zn6Gd相相继形成。共晶 W 相与 Mg 基体具有 120 mV 的最高电位差，加速了微电偶腐蚀。连续分布且尺寸过小的 I 相导致均匀腐蚀。由于 X 相和基体之间相对较低的电位差、腐蚀屏障效应和典型的 {0002} 织构成分，挤压态 Mg-3Zn-11Gd-0.6 Zr 合金表现出优异的耐腐蚀性。