Corrosion Characteristics of an Ultrafine-Grained Al-Mg-Si Alloy (AA6082)
Corrosion Characteristics of an Ultrafine-Grained Al-Mg-Si Alloy (AA6082)
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DOI：
10.4028/www.scientific.net/msf.584-586.988
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发表时间：
2008-06
期刊：
影响因子：
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通讯作者：
B. Wielage;D. Nickel;T. Lampke;Gert Alisch;H. Podlesak;S. Darwich;M. Hockauf
中科院分区：
文献类型：
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作者：
B. Wielage;D. Nickel;T. Lampke;Gert Alisch;H. Podlesak;S. Darwich;M. Hockauf
研究了AA6082铝合金经等通道转角挤压(ECAP)后不同道次(E路线，室温)后的腐蚀行为，并与粗晶铝合金进行了对比。给出了腐蚀前后的电化学测试结果(循环伏安法、电化学阻抗谱，EIS)与微观结构的关系。化学(析出相、相)和物理(位错、大角度晶界、晶粒度、小角度晶界)的不均匀性表征了这种商用Al-Mg-Si合金的微观组织。结果表明，ECAP材料的抗点蚀性能得到了改善，表现为点蚀密度降低了50%，坑深减小。交流阻抗测量和显微结构测试(扫描电子显微镜、透射电子显微镜、三维形貌测量)证实，ECAP改变了这些不均匀的数量、大小和分布，从而导致更有利的腐蚀行为。
The corrosion behaviour of the aluminium alloy, AA6082, processed by equal-channel angular pressing (ECAP) after different passes (route E, room temperature) was studied in comparison to the coarse-grained counterpart. The results of the electrochemical investigations (cyclovoltammetry; electrochemical impedance spectroscopy, EIS) are presented in correlation with the microstructure before and after the corrosion examinations. Both, chemical (precipitations, phases) and physical (dislocations, high-angle grain boundaries, grain size, low-angle grain boundaries) inhomogeneities characterize the microstructure of this commercially used Al-Mg-Si alloy. Results indicate an improved resistance against pitting of the ECAP material expressed by a reduced pitting density of up to 50 % and lower pit depths. EIS measurements and microstructural examinations (scanning electron microscopy, transmission electron microscopy, 3D topography measurement) confirm that ECAP modifies the number, size and distribution of these inhomogeneities, which leads to a more favourable corrosion behaviour.