稀土Ce对7A04铝合金耐腐蚀性能的影响

发布时间：2018-06-07 03:43

本文选题：稀土Ce + 周期浸润腐蚀试验　；参考：《表面技术》2017年10期

【摘要】：目的提高7A04铝合金的耐腐蚀性能。方法采用周期浸润腐蚀试验模拟海洋大气环境,研究了不同稀土Ce含量的7A04铝合金的腐蚀行为及规律。通过金相显微镜和扫描电子显微镜,观察了不同试样的组织和夹杂物形貌。采用失重法和电化学阻抗技术,分析了试样的腐蚀动力学规律及电化学行为特性。结果在Ce质量分数分别为0%、0.39%和0.81%的7A04铝合金中,稀土Ce的加入量为0.39%时,其晶粒最细小,第二相与夹杂最少且分布最均匀,合金的基体组织得到了改善。稀土7A04铝合金的腐蚀失重明显低于不含稀土Ce的7A04铝合金,且锈层电阻升高,其中含0.39%稀土Ce的7A04铝合金的锈层电阻最高。结论三种7A04铝合金均发生了明显的局部腐蚀,主要为点蚀。稀土Ce的加入,改变了非稀土铝合金中的T相和S相,生成了新的细小的块状金属间化合物,改善了组织的均匀性,提高了其腐蚀锈层电阻,增加了锈层对基体的保护能力,使铝合金耐海洋大气腐蚀性能提高。在三种稀土Ce含量的铝合金中,含0.39%稀土Ce的7A04铝合金的耐蚀性最佳。
[Abstract]:Objective to improve the corrosion resistance of 7A04 aluminum alloy. Methods the corrosion behavior and regularity of 7A04 aluminum alloy with different rare earth ce content were studied by using periodic immersion corrosion test to simulate marine atmospheric environment. The microstructure and inclusion morphology of different samples were observed by metallographic microscope and scanning electron microscope. The corrosion kinetics and electrochemical behavior of the samples were analyzed by weightlessness and electrochemical impedance technique. Results in the 7A04 aluminum alloy with 0.39% ce content and 0.81% ce content, the rare-earth ce content was 0.39%, the grain size was the smallest, the second phase and inclusions were the least and the distribution was the most uniform, and the matrix structure of the alloy was improved. The corrosion weight loss of rare earth 7A04 aluminum alloy was obviously lower than that of 7A04 aluminum alloy without rare earth ce, and the rust resistance of 7A04 aluminum alloy containing 0.39% rare earth ce was the highest. Conclusion all three kinds of 7A04 aluminum alloys have obvious local corrosion, mainly pitting corrosion. The addition of rare earth ce changed the T phase and S phase in the non-rare earth aluminum alloy, and formed a new small block intermetallic compound, which improved the uniformity of the microstructure, increased the corrosion resistance of the rust layer, and increased the protective ability of the rust layer on the substrate. The corrosion resistance of aluminum alloy to marine atmosphere is improved. The corrosion resistance of 7A04 aluminum alloy containing 0.39% rare earth ce is the best among the three kinds of rare earth ce content aluminum alloys.
【作者单位】：内蒙古科技大学材料与冶金学院;
【基金】：内蒙古自然科学基金资助项目(2014MS0525,2015MS0555)~~
【分类号】：TG146.21;TG172

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