Abstract

In order to improve the overall properties of cast Al–Cu–Mn alloy, the effect of Zr content on the microstructure and corrosion resistance of Al–Cu–Mn alloy was investigated. The microstructures of the alloy were analyzed by scanning electron microscopy and transmission electron microscopy, and the corrosion resistance of the alloy was tested by exfoliation corrosion (EXCO), intergranular corrosion (IGC) and electrochemical corrosion tests. The results show that the corrosion resistance of Al–Cu–Mn alloy with 0.2 wt % Zr is superior to other alloys. Specifically, the EXCO phenomenon of the alloy is lighter, and the rating of EXCO is EA. The IGC depth of the alloy can reach the lower value (56.3 μm). The electrochemical self-corrosion potential (E_corr), corrosion current (i_corr) and corrosion rate (R_corr) are –0.8046 V, 0.0028 mA m^–2 and 0.1558 mm a^–1, respectively. The improved corrosion resistance of the Al–Cu–Mn alloy with 0.2 wt % Zr resulted from the formation of the T phase and more uniform dispersive distribution of the Al₃Zr phase in the alloy.

中文翻译：

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Zr含量对Al-Cu-Mn合金显微组织和耐蚀性的影响

摘要

为提高铸造Al-Cu-Mn合金的综合性能，研究了Zr含量对Al-Cu-Mn合金显微组织和耐蚀性的影响。采用扫描电镜和透射电镜分析合金的显微组织，采用剥落腐蚀（EXCO）、晶间腐蚀（IGC）和电化学腐蚀试验测试合金的耐蚀性能。结果表明，含 0.2 wt% Zr 的 Al-Cu-Mn 合金的耐腐蚀性优于其他合金。具体来说，合金的EXCO现象较轻，EXCO等级为EA。合金的IGC深度可以达到较低值(56.3 μm)。电化学自腐蚀电位（E _corr）、腐蚀电流（i_corr ) 和腐蚀速率 ( R _corr ) 分别为 –0.8046 V、0.0028 mA m ^–2和 0.1558 mm a ^–1。_{添加 0.2 wt% Zr 的 Al-Cu-Mn 合金的耐腐蚀性提高是由于 T 相的形成和合金中 Al 3} Zr 相更均匀的分散分布。