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中性介质铝表面无机非金属膜层的电化学沉积 (Ⅲ)无机非金属膜层成膜机理初探 总被引:2,自引:1,他引:1
通过分别测定铝在成膜促进剂、络合成膜剂和Na2WO4的不同组合体系中的稳态伏安特性曲线和暂态阳极氧化曲线,及铝在成膜促进剂+络合成膜剂+Na2WO4体系中不同氧化阶段形成的膜层的显微形貌,初步提出了无机非金属膜层的成膜机理,即在特殊电解液和工艺条件下,铝/电解液界面上形成带负电含铝胶体粒子,由于界面化学、电化学和焦尔热的作用,胶体层在阳极不均匀沉积、浓缩、脱水和快速冷却,导致具有特殊结构和性能的无机非金属膜的形成。 相似文献
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1 前言铝及铝合金一般都采用硫酸阳极氧化以获得致密氧化膜层。硫酸阳极化电解液成分简单 ,操作方便 ,应用广泛。但硫酸阳极化操作温度一般要求在2 5°C以下 ,高于 2 5°C ,氧化膜会发生疏松粉化、抗蚀性能差、膜层薄且脆、硬度降低、耐磨性较差等疵病。因此 ,硫酸阳极氧化处理通常都配备冷却装置或采用压缩空气搅拌来稳定阳极化电解液的温度。本文就改进硫酸阳极化工艺 ,提高阳极化电解液工作温度 ,从而改善阳极氧化膜质量 ,谈点滴体会。2 铝或铝合金宽温快速氧化成膜机理探讨在铝或铝合金硫酸阳极化整个过程中 ,氧化膜的生成和溶解是… 相似文献
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以磷酸溶液为电解液、以高纯铝为阳极,采用两步阳极氧化法制备氧化铝模板。扫描电子显微镜(SEM)对其表面形貌分析表明,氧化铝膜为多孔结构,膜孔径随着阳极氧化电压的增大而不断增大。对阳极氧化电流密度变化分析证实,铝的阳极氧化经历了三个阶段:阻挡层的生成、多孔层的形成和多孔层的稳定生长。以制备的氧化铝膜为阴极、锌片为阳极,以硝酸锌和硼酸的混合液为电解液,采用交流电沉积方法制备了针状氧化锌纳米线。 相似文献
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为提高AZ91D镁合金耐蚀性且满足绿色环保要求,在阳极氧化电解液中添加环保型添加剂聚天冬氨酸(PASP)制备阳极氧化膜,研究添加剂聚天冬氨酸对阳极氧化过程、氧化膜的形貌及组成和耐腐蚀性能的影响。采用光学显微镜、带能谱的扫描电镜及X射线衍射仪,观察分析添加聚天冬氨酸前后阳极氧化膜的形貌及组成,利用动电位极化及浸泡腐蚀等方法,研究分析阳极氧化后AZ91D镁合金的耐腐蚀性能。结果表明:聚天冬氨酸通过与镁合金表面的吸附作用,使膜层阻抗增大,阳极氧化成膜电压升高,膜厚增大,膜层致密、均匀、平整,微孔和裂纹减少,提高了氧化膜的耐腐蚀性能。 相似文献
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镁及镁合金环保型阳极氧化工艺研究 总被引:7,自引:1,他引:7
研究了镁及镁合金无铬、无磷的环保型阳极氧化工艺测定了镁阳极氧化的稳态伏安曲线和电流密度一时间曲线通过研究氧化电压、电解液中NaOH和Al(0H)3的浓度、电解液温度、氧化时间等对镁阳极氧化成膜的影响,确定了最佳工艺条件分析了最佳工艺条件下得到的镁合金氧化膜的成分、结构与表面形貌,并对镁合金基体与氧化膜的耐腐蚀性能进行了比较结果表明,在环保型阳极氧化液中得到的镁合金氧化膜由镁和铝的氧化物组成,其色泽光滑,结构致密,与镁合金基体相比硬度与耐腐蚀性能都大为提高。 相似文献
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对汽车用2024铝合金板材进行酒石酸阳极氧化处理,并研究了阳极氧化对铝合金的成分、结构、表面形貌及耐蚀性的影响。研究发现,铝合金阳极氧化膜是由表面多孔层和内部无孔层构成的。铝合金阳极氧化过程是一个氧化铝生成和溶解的动态过程。阳极氧化膜由刚玉结构的α-Al_2O_3和八面结构的γ-Al_2O_3构成,α相和γ相大大提高了阳极氧化膜的硬度和耐蚀性。阳极氧化膜为典型的多孔结构,孔洞分布均匀,孔径为50nm左右。 相似文献
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在钛合金表面采用阳极氧化工艺制备出氧化钛薄膜。通过实验验证了阳极氧化原理,得出在不同的氧化电压下可生成不同厚度的氧化钛薄膜,薄膜越薄呈色越鲜艳;并分析了阳极氧化电解液对形成薄膜的影响;最后模拟分析了氧化薄膜的生长过程。 相似文献
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以铝箔为阳极,石墨为阴极,草酸为电解液,采用二次阳极氧化法制备透明氧化铝薄膜。采用金相显微镜观察一次阳极氧化和二次阳极氧化后氧化铝薄膜的表面形貌,并用X射线衍射仪对氧化铝薄膜结构进行表征。结果表明,二次阳极氧化工艺对氧化铝薄膜的质量有重要的影响。采用退火-除油-浸蚀-电化学抛光-一次阳极氧化-二次阳极氧化工艺,并严格控制工艺参数,可以制备结构良好的透明氧化铝薄膜,且氧化铝薄膜是非晶态结构。 相似文献
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Huiquan WuKurt R Hebert 《Electrochimica acta》2002,47(9):1373-1383
Electrochemical current and potential transients were measured during anodic oxidation of aluminum, on time scales of 0.1-100 ms after anodizing began. Aluminum foil samples were prepared by surface treatments yielding oxide films of thickness 5 nm or smaller. A mathematical model was developed for the transients based on steady-state and transient conduction phenomena established for much thicker anodic films. Model calculations and experimental transients were in quantitative agreement, indicating that the electrochemical behavior of the nanometer-thick films during their growth is strongly similar to that of anodic films. No electrochemical processes other than uniform oxide growth were detected, as might have been associated with defects constituting easy conduction paths. The rate of oxide growth was shown to be controlled by oxygen ion transfer at the film-solution interface. 相似文献
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The adhesion of low-density polyethylene to porous anodic films on aluminum was studied using the 180° peel test. Relative values of bond strengths, obtained by using polymer with and without antioxidant and by forming the bond in air or in vacuo, indicated that good adhesion could be obtained, despite previous evidence to the contrary, in conditions where oxidation of the polyethylene was suppressed. The relation between peel strength and anodic film thickness and film-forming voltage implied that the polyethylene entered pores in the film during bond formation. This was supported by the change of the category of the adhesion to one dependent upon polymer oxidation when the pores in the anodic film were sealed prior to bond formation. It is suggested that the mechanism of adhesion to porous anodic films on aluminum involves keying of the polymer into the pores in the film. 相似文献
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Lassiné Ouattara Stéphane Fierro Olivier Frey Milena Koudelka Christos Comninellis 《Journal of Applied Electrochemistry》2009,39(8):1361-1367
Surface redox activities, oxygen evolution reaction (OER), oxidation of formic acid (FA), and anodic stability were investigated
and compared for IrO2 electrodes prepared by two techniques: the thermal decomposition of H2IrCl6 precursor (TDIROF) and the anodic oxidation of metallic iridium (AIROF). Surface redox activities involved on the AIROF were
found to be much faster than those involved on the TDIROF. Concerning the oxygen evolution reaction, both films show a similar
mechanism and specific electrocatalytic activities. The situation seems to be different for FA oxidation. In fact, on TDIROF,
the oxidation of FA and the OER compete involving the same surface redox couple Ir(VI)/Ir(IV) contrary to FA oxidation on
AIROF, where the Ir(V)/Ir(IV) surface redox couple is involved. Finally, electrode stability measurements have shown that
contrary to TDIROF, which are very stable under anodic polarization, the AIROF are rapidly corroded under anodic treatment.
This corrosion is enhanced even further in the presence of formic acid. 相似文献
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为比较在高压阳极氧化条件下不同电解液体系中碱性含氧酸盐对6063铝合阳极氧化膜层厚度及氧化时间的影响,将6063铝合金置于Na2SiO3、Na2HPO4和NaAlO2三种电解液体系中制备出阳极氧化膜。用涡流测厚仪测试了膜层厚度,通过点滴腐蚀实验评价了Na2SiO3体系所得氧化膜的耐腐蚀性能,利用扫描电子显微镜(SEM)观察分析了氧化膜的表面形貌。结果表明,钨酸钠能显著提高膜层厚度和膜层的耐腐蚀性能,六偏磷酸钠(SHMP)能延长氧化时间,提高膜层的硬度;在硅酸盐体系中钨酸钠和六偏磷酸钠按1∶1的比例加入,能得到致密的高耐蚀性阳极氧化膜层。 相似文献