铝合金钼酸盐转化膜研究

采用电化学方法研究了铝合金表面钼酸盐化学转化膜。实验结果表明处理工艺简单,成膜速度快。铝合金钼酸盐转化膜提高了铝合金的耐蚀性能。有效的抑制了铝合金在w（NaCl）=3.5%溶液中的点蚀。并讨论了各种添加剂的作用。     

镀锌层钼酸盐转化膜及其耐蚀机理

应用极化曲线和交流阻抗的方法研究了镀锌层钼酸盐转化膜在5％NaCl的溶液中的耐蚀性，结果表明，钼酸盐转化膜处理能显著地提高镀锌层的耐腐蚀能力，分析了转化膜的成膜机理，并从转化膜对镀锌层在5％ NaCl溶液中的阴、阳极反应历程的影响及交流阻抗行为的变化，分析了钼酸盐转化膜的耐蚀机理。     

铝合金铈盐转化膜的研究

提出了一种铝合金铈盐化学转化成膜工艺,利用电化学方法研究了铝合金铈盐化学转化膜的成膜过程及耐蚀性能,结果表明,成膜促进剂的加入能有效提高铈盐转化膜的成膜速度,所得转化膜对铝合金的点蚀有较好的抑制作用。     

热镀锌板钼酸盐化学转化溶液寿命及其成分变化规律的研究

热浸镀锌钢板在钼酸盐溶液中形成了钼酸盐化学转化膜。研究了处理液的使用寿命及成分变化对转化膜耐腐蚀性能的影响。采用极化曲线测试方法对转化膜的耐蚀性能进行评价。用电感耦合等离子体发射光谱对处理液中各成分进行分析。结果表明,新配制的500mL钼酸盐处理液,在持续处理试样面积达到1.440m2后失去钝化能力。扫描电镜观察发现,耐蚀性良好的转化膜表面均匀致密。电子能谱分析表明,转化膜主要由O、Zn、P和Mo元素组成。     

铝合金LY12表面四价铈转化膜工艺及耐蚀性研究

利用浸渍法在铝合金ＬＹ１２表面上获得了稀土转化膜。确定了成膜的最佳工艺。利用湿热试验、盐水浸渍试验、电化学测试方法评价了膜的耐蚀性能。提出了膜的耐蚀机理。     

铝合金LY12表面四价转化膜工艺及耐蚀性研究

利用浸渍 法在铝合金ＬＹ１２表面上获得了稀土转化膜，确定了成膜的最佳工艺，利用湿热试验，盐水浸渍 试验，电化学测试方法评价了膜的耐蚀性能，提出了膜的耐蚀机理。     

铝合金表面有色转化膜快速成膜工艺

在含有Ti/Zr的处理液中加入单宁酸、有机缓蚀剂和硫酸锰,在铝合金基体上得到了耐蚀性能优异的金黄色转化膜。研究了处理液各组分对转化膜外观以及耐蚀性能的影响,确定了成膜的最佳工艺为:H2TiF6 7 g/L,H2ZrF6 1 g/L,F-3 g/L,单宁酸7 g/L,硫酸锰5 g/L,有机酸缓蚀剂2 g/L,pH 4.9,成膜时间10 min。研究表明,单宁酸和H2TiF6是转化膜着色的关键,二者缺一不可。由最佳工艺得到的转化膜的自腐蚀电流密度是铝合金基体的1.3%,耐蚀性能明显提高。     

变形铝合金表面锆基化学转化膜的研究现状

化学转化膜是金属表面主要的处理方法之一,具备良好的附着力和耐蚀性,能为铝合金提供一定的临时防护。传统的六价铬酸盐化学转化膜在日渐严苛的环保压力下已经逐渐淘汰,取而代之的是近几年发展迅猛的三价铬及无铬锆基化学转化膜。铝合金可分为铸造铝合金和变形铝合金,按照所含主要合金元素和热处理状态可分为若干个系列和型号。本文选取几种典型的变形铝合金,综述了不同铝合金微观组织对转化膜成膜过程的影响,化学转化液添加剂、预处理和后处理工艺对转化膜性能的调控及作用机理,以及几种典型商业钝化剂在变形铝合金表面的应用。总结了目前变形铝合金表面锆基化学转化膜仍面临的问题和发展趋势,未来化学转化膜需在满足新型铝合金发展要求的基础上,通过不同有机、无机添加剂以及外场作用对转化膜的成膜均一性、完整性进行调控,以提高转化膜的综合性能。     

铝合金稀土转化膜工艺及性能研究

以Ce(NO_3)_3为主要成膜剂,采用正交试验法和单因素试验法研究了6061铝合金的稀土转化成膜工艺,并对转化膜的表面形貌、成分和耐蚀性进行了分析。试验结果表明:转化膜为棕黄色;转化膜中含有铈、锰元素;稀土转化处理的铝合金硫酸铜点滴试验达到340 s以上,电化学测试自腐蚀电流密度icorr相比铝合金基体降低了2个数量级,极化电阻约是未处理的93倍,有效提高了铝合金的耐蚀性能。     

铝合金稀土铈转化膜的研究

利用漫溃法在铝合金上获得了金黄色的稀土转化膜,确定了成膜的最佳工艺条件.利用盐水浸渍试验评价了膜的耐蚀性能,并和传统的钝化膜及阳极氧化膜进行了比较.结果表明:稀土转化膜的耐蚀性能优于含铬转化膜和阳极氧化膜.利用电化学方法研究了稀土转化膜的耐蚀机理;扫描电镜观察了膜的微观形态;X衍射测试证明稀土转化膜含有铈的氧化物和氢氧化物.稀土转化膜工艺简单,对环境无污染,膜的耐蚀性强,具有一定的应用前景.     

镁合金钼酸盐、钼酸盐-磷酸盐转化膜的研究

研究了镁合金表面钼酸盐转化膜以及钼酸盐-磷酸盐复合转化膜,探讨了两种转化膜的组成、形态、极化曲线及耐盐水腐蚀性。发现钼酸盐-磷酸盐转化膜微观表面呈均匀"蜂窝"状,较单一的钼酸盐转化膜具有更好的耐腐蚀性。     

Composite anticorrosion coatings for AZ91D magnesium alloy with molybdate conversion coating and silicon sol–gel coatings

This study evaluated the corrosion resistance of AZ91D magnesium alloy coated by composite coatings which consisted of a molybdate conversion coating and three layers of silicon sol–gel coatings. For molybdate conversion treatment, various conditions including the pH of the molybdate baths, immersion time and bath temperature were investigated using electrochemical measurements. The corrosion resistance of the AZ91D magnesium alloy was improved to some extent by the conversion coating with the optimal conversion parameters (7.3 g/L (NH₄)₆Mo₇O₂₄·6H₂O solution with pH 5 for 30 min at 30 °C).     

铝合金表面电解沉积稀土转化膜工艺研究

研究了一种通过电解沉积方法在防锈铝LF21表面上生成铈盐转化膜的工艺,应用正交实验研究了有关因素对成膜过程的影响并获得了最佳的技术参数用极化曲线、交流阻抗和中性盐雾试验等方法测试了该工艺形成膜层的耐蚀性能及其组成一结果表明：经过电解沉积稀土转化膜处理后,防锈铝的阳极腐蚀过程受到了阻滞,自然腐蚀电位负移;与经过化学转化膜处理后相比,其耐蚀性能有显著提高,可通过400h的中性盐雾实验,亲水性能亦有明显提高。     

Electrochemical and salt spray analysis of multilayer ormosil/conversion coating systems for the corrosion resistance of 2024-T3 aluminum alloys

The corrosion resistance characteristics of multilayer coating systems comprised of a conversion coating base layer and an organically modified silicate (ormosil) topcoat have been analyzed using salt spray and potentiodynamic polarization curve analyses. The effectiveness of the multilayer coating systems was found to depend on the presence of an electrochemically active species in the conversion coating and on the presence of a curing agent in the ormosil system. Multilayer coatings systems comprised of conversion coatings that contain active corrosion inhibitors were found to provide high degrees of corrosion protection. In all cases, the presence of the ormosil was found to enhance the corrosion resistance of the underlying conversion coating. The use of multilayer ormosil/conversion coating systems enhances the corrosion protection of 2024-T3 aluminum alloy by combining previously developed corrosion protection methods with emerging sol-gel technology. Environmental Institute, Stillwater, OK 74078.     

高耐蚀性Zn—Co合金镀层钝化工艺的研究

研究了电镀Zn-Co合金镀层的钝化液的组成及工艺条件，溶液各成分及工艺条件对钝化膜质量的影响，通过几种腐蚀试验方法，测量了钝化膜的耐蚀性，结果表明，研究的钝化工艺可以得到耐蚀性良好的钝化膜。     

Nanostructured coatings approach for corrosion protection

Nanostructured surface treatment coatings based on the Self-assembled Nanophase Particle (SNAP) approach were investigated as potential replacement for chromate-based surface treatments on aircraft aluminum alloys. In the traditional sol–gel method, hydrolysis-condensation processes are followed by condensation polymerization upon film application. This process sequence provides a low temperature route to the preparation if thin coatings which are readily applied to most metallic substrates. The recent discovery of a method of forming functionalized silica nanoparticles in situ in an aqueous sol–gel process, and then cross-linking the nanoparticles to form a thin film, is an excellent example of a nanoscience approach to coatings. This Self-assembled Nanophase Particle (SNAP) process can be used to form thin, dense protective organic surface treatment coatings on Al aerospace alloys. The ability to design coating components from the molecular level upward offers tremendous potential for creating multifunctional coatings.

The important components of Al alloy corrosion inhibition by chromate are storage and release of Cr^VI species, inhibition of cathodic reactions (primarily oxygen reduction), and inhibition of attack at active sites in the alloy. Unlike chromate-based treatments, current SNAP coatings provide barrier-type corrosion resistance but do not have the ability to leach corrosion inhibitors upon coating damage and minimize corrosion of the unprotected area. In this study, organic inhibitors were tested for corrosion protection of aluminum alloys in combination with the (SNAP). Scanning Vibrating Electrode Technique, anodic polarization, electrochemical impedance spectroscopy, and salt spray test were used to study this new approach for chromate replacement.