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研究AA2024-T3、AA5083-O和AA6082-T6合金的腐蚀路径,以进一步了解铝合金局部腐蚀机理。采用扫插电子显微镜研究合金在3.5%Na Cl溶液中动电位极化测试后腐蚀表面,利用扫描振动电极技术分析阳极电解液的流动。结果表明:各合金的腐蚀路径明显不同,且受阳极电解液流动的影响。另外,在AA5083-O和AA6082合金中,腐蚀以两种方式进行扩展:一种为腐蚀前端扩展路径(AA5083的丝状扩展路径和AA6082合金有条理的线性扩散路径);另一种为沿?100?方向的晶体学通道扩展路径。与AA2024-T3合金相比,AA5083-O和AA6082-T6合金的扩展路径与晶粒特征有关,而与粗大的第二相粒子无关。而AA2024-T3的扩展路径与第二相粒子和晶界特征有关。
The corrosion path of AA2024-T3, AA5083-O and AA6082-T6 alloys was studied to further understand the local corrosion mechanism of aluminum alloy. The scanning electron microscope was used to study the corrosion of the alloy after the potentiodynamic polarization test in 3.5% NaCl solution. The flow of the anolyte was analyzed by scanning vibrating electrode technique. The results show that the corrosion path of each alloy is obviously different and influenced by the flow of anolyte. In addition, in the AA5083-O and AA6082 alloys, the corrosion is extended in two ways: one for the corrosion front-end extension path (the linear extension path for the AA5083 and the AA6082 alloy) and the other for the edge- 100 方 direction of the crystal channel expansion path. Compared with AA2024-T3 alloy, AA5083-O and AA6082-T6 alloy’s extension path is related to the grain characteristics, but not with the coarse second-phase particles. The extension path of AA2024-T3 is related to the second-phase particles and grain boundary features.