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研制了一种新型的铝合金 Ce- Mo基转化膜工艺—— AM工艺。此种工艺的成膜溶液组成为 :(NH4) 2 Ce(NO3) 6 2 .5 g/ L,Na KC4H4O6 · 4H2 O2 .5 g/ L,Na2 CO37.5 g/ L,Na2 Mo O45 .0 g/ L。铝合金浸在沸腾的此种成膜溶液中2 0 min,可形成约 3.6μm厚的铝合金 Ce- Mo基转化膜。于 5 % Na Cl溶液中进行的极化曲线测试和浸泡试验表明 ,对L F6铝合金 ,经 AM工艺处理形成的转化膜其抗局部腐蚀能力超过了传统的铝合金铬酸盐转化膜。但对 L C4铝合金 ,此种转化膜的耐蚀性能不理想。EDAX和 SEM分析表明 ,L F6和 L C4两种铝合金上形成的 AM转化膜主要由 Al,Ce,Mo的氧化物或氢氧化物组成 ,但它们的表面形貌差异很大。
A new type of aluminum alloy Ce-Mo based conversion coating process - AM process was developed. The composition of the film-forming solution of this process is as follows: (NH4) 2 Ce (NO3) 6 2.5g / L, Na KC4H4O6 4H2 O2.5g / L, Na2 CO37.5g / L, Na2 Mo O45.0 g / L. The aluminum alloy immersed in such a boiling solution for 20 min to form a 3.6 μm thick aluminum alloy Ce-Mo-based conversion coating. Polarization curves and immersion tests in 5% NaCl solution showed that the anti-localized corrosion resistance of the conversion coating formed by AM process was higher than that of the conventional aluminum alloy chromate conversion coating for L F6 aluminum alloy. However, for L C4 aluminum alloy, the corrosion resistance of this conversion coating is not satisfactory. EDAX and SEM analysis showed that the AM conversion coatings formed on the two aluminum alloys of L F6 and L C4 are mainly composed of oxides, hydroxides of Al, Ce and Mo, but their surface topography is very different.