Galvanic compatibility of corrosion protective coatings with AA7075 aluminum alloy
Galvanic compatibility of corrosion protective coatings with AA7075 aluminum alloy
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AA7075铝合金防腐蚀涂层的电偶相容性
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
J. de Wit
中科院分区：
文献类型：
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作者：
Z. F. Lodhi;W. Hamer;J. Mol;H. Terryn;J. de Wit
研究了航空铝合金AA7075与镉(Cd)、锌(Zn)和锌钴铁(Zn-Co-Fe，32-37%Co和1%Fe)合金的电偶兼容性。在0.6 mMNaC l溶液中的开路电位[OCP与饱和甘汞电极]的比较表明，除锌钴铁(37%Co + 1%Fe)合金对AA7075呈正电作用外，所有涂层都对AA7075起阳极作用。在0.6M氯化钠电解液中进行零电阻安培法(ZRA)测量时，在浸泡7d时，测量了耦合的OCP和电流密度，发现锌和镉都是阳极，因此对AA7075是牺牲的。AA7075铝合金与(37%Co + ，1%Fe)Zn-Co-Fe合金的电偶联会导致AA7075铝合金的溶解。而锌钴铁(32%Co + 1%Fe)合金在浸泡的前26h对AA7075铝合金是阳极，但在脱锌和钴在表面富集后对AA7075铝合金是阴极。在与锌的偶合过程中，AA7075也观察到了一些点蚀现象。
The galvanic compatibility of aerospace aluminum alloy AA7075 with cadmium (Cd), zinc (Zn), and zinc–cobalt–iron (Zn–Co–Fe, 32–37%Co and 1%Fe) alloys was investigated. A comparison of open circuit potential [OCP vs. saturated calomel electrode (SCE)] measurements in 0.6 mM NaCl showed that all coatings would act anodically to AA7075 with an exception of Zn–Co–Fe (37%Co + 1%Fe) alloy which was electropositive to AA7075. During the zero resistance ammetry (ZRA) measurement in 0.6 M NaCl electrolyte the coupled OCP and current density were measured during 7 days of immersion and both Zn and Cd acted anodic and thus sacrificial to AA7075. Galvanic coupling of AA7075 with (37%Co + 1%Fe) Zn–Co–Fe alloy resulted in the consequent dissolution of the AA7075 aluminum alloy. In contrast, Zn–Co–Fe (32%Co + 1%Fe) alloy was found to be anodic to AA7075 during the first 26 h of immersion but after dezincification and cobalt enrichment at the surface became cathodic to the AA7075 aluminum alloy. During coupling with Zn, some pitting was also observed on AA7075.