AA6061铝合金在含盐薄液膜下的局部腐蚀与缓蚀机理

发布时间：2018-01-16 00:17

本文关键词：AA6061铝合金在含盐薄液膜下的局部腐蚀与缓蚀机理　出处：《中国腐蚀与防护学报》2017年04期 　论文类型：期刊论文

【摘要】：采用极化曲线、电化学阻抗、电化学噪声以及形貌观测研究了AA6061铝合金在3.5%(质量分数)NaCl薄液膜下的点蚀诱发以及缓蚀剂抑制过程。结果表明:在Na Cl薄液膜下,Ce~(3+)作为阴极性缓蚀剂往往在铝合金表面的第二相组织(如Mg2Si等微阴极相)碱化区发生优先沉积,使铝合金局部腐蚀受到抑制;薄液膜越薄,Ce~(3+)在微阴极区形成的沉积层越致密,进而显著抑制铝合金微阴极相表面的氧还原过程以及亚稳态点蚀的萌生和稳态点蚀发展。相反,在含相同浓度Ce~(3+)的Na Cl溶液中,由于Ce~(3+)的氧化过程受到溶液中氧扩散速率的限制,导致Ce~(3+)在溶液中对亚稳态点蚀的抑制能力相比薄液膜有所下降,即薄液膜下Ce~(3+)的局部腐蚀抑制能力强于本体溶液中的。
[Abstract]:The polarization curves, electrochemical impedance, electrochemical noise and morphological observation of AA6061 Aluminum Alloy in 3.5% (mass fraction) pitting NaCl thin film and the inhibition process. The results showed that: in the Na Cl thin film, Ce~ (3+) as the cathode of corrosion inhibitor are often in the second phase Aluminum Alloy the surface (such as Mg2Si micro cathode) occurs preferentially deposited alkaline region, the local corrosion Aluminum Alloy inhibited; the thin film is thin, Ce~ (3+) in the sediments formed more compact micro cathode region, the development of initiation and steady-state pitting and inhibit the Aluminum Alloy micro cathode surface oxygen reduction process and sub the steady pitting. On the contrary, containing the same concentration of Ce~ (3+) Na Cl solution, because the Ce~ (3+) oxidation by oxygen diffusion rate in the solution, leading to Ce~ (3+) in the solution of inhibition of metastable pitting of thin film has been compared The local corrosion inhibition of Ce~ (3+) under thin liquid film is stronger than that in the bulk solution.

【作者单位】：华中科技大学化学与化工学院材料服役失效湖北省重点实验室;中航工业特种飞行器研究所;湖北文理学院化工与食品学院;
【基金】：国家自然科学基金(51371087)~~
【分类号】：TG178
【正文快照】： 铝合金因密度小,力学性能优异等优点被广泛应用于建筑、汽车、电子及航空航天工业等领域[1-4]。铝合金大气腐蚀尤其是海洋性大气腐蚀极为普遍,研究铝合金的大气腐蚀机理和抑制方法,对选择合理的防护方法、延长飞机或舰船服役寿命十分重要[5]。大气中腐蚀性物质的存在加速了金

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