Abstract Formation of second phases in as-cast Mg-xNd-0.3Zr (x = 0, 5 and 11) alloys was characterized and the role of second phases on the corrosion resistance was investigated. Mg12Nd second phase with a semi-continuous network along grain boundary was formed in Mg-5Nd-0.3Zr alloy and the formed Mg12Nd second phase acted as corrosion barrier, which improved the corrosion resistance. A higher area fraction of second phase along grain boundary was formed in Mg-11Nd-0.3Zr alloy while the second phase was composed of Mg41Nd5 and Mg12Nd with a lamellar structure. Instead of corrosion barrier, cracks were formed along the second phase during the corrosion process in Mg-11Nd-0.3Zr alloy, which resulted in the fall out of grains and an intergranular corrosion behavior. This result indicated there was a limitation of corrosion barrier effect of second phases in Mg-Nd-Zr alloys.

中文翻译：

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第二相对 Mg-Nd-Zr 合金耐蚀性的影响

摘要 表征了铸态 Mg-xNd-0.3Zr (x = 0、5 和 11) 合金中第二相的形成，并研究了第二相对耐腐蚀性能的作用。Mg-5Nd-0.3Zr合金中沿晶界形成具有半连续网络的Mg12Nd第二相，形成的Mg12Nd第二相作为腐蚀屏障，提高了耐蚀性。Mg-11Nd-0.3Zr合金沿晶界形成了较高的第二相，而第二相由层状结构的Mg41Nd5和Mg12Nd组成。Mg-11Nd-0.3Zr合金在腐蚀过程中沿第二相形成裂纹而不是腐蚀屏障，导致晶粒脱落和晶间腐蚀行为。