铝及铝合金阳极氧化膜常温封闭技术

为提高铝及其合金氧化膜的耐蚀性和耐污能力,必须对膜作常温耐封闭处理。为此,研究了在GA-93（A）封闭剂中添加环己酮,减少缓冲剂的用量,以提高铝及其合金氧化膜常温封闭质量的方法。讨论了封闭材料表面的影响,结果表明,封闭后的材料表面质量符合ISO3210要求。用本封闭剂处理的铝材料表面光滑。     

铝阳极氧化膜的常温封闭

本文简要介绍了铝阳极氧化膜常温封闭的发展历史沿革和作用原理,重点介绍了当今国外广泛使用的镍——氟化物系常温封闭剂的主要组成和工艺条件.     

铝合金硬质阳极氧化工艺试验

铝合金硬质阳极氧化工艺试验贵阳市１７７信箱７分箱（５５０００９）杨旭江，姚茂年１前言在我厂新品试制中，有部分铝合金件需进行硬质阳极氧化加工，其技术要求是零件工作面氧化膜厚度３５～４０ｐｍ，硬度ＨＶ＞５１０。若按航标进行加工，仅有少数零件达到技术要求。...     

铝及铝合金瓷质阳极氧化工艺的研究

对铝及铝合金在磺基水杨酸槽液中及另一有机酸槽中进行二次氧化，获得了装饰效果良好的瓷质氧化膜。分析研究了各工艺参数对膜层性能的影响。该工艺操作简单，工艺范围宽，无污染，所得膜层性能好。     

铝及铝合金的硬质阳极氧化

本文阐述了以硫酸为基添加草酸的常温氧化溶液对铝及铝合金硬质阳极氧化的影响。试验表明,所选用的溶液成份是可行的。与其他常温硬质阳极氧化溶液相比,具有成份简单、易于控制的优点。可提高氧化溶液的温度,所形成的氧化膜其显微硬度大于300HV,厚度可达100微米以上,适于工业生产推广应用。     

3003铝合金阳极氧化、封闭工艺对其绝缘性能的影响

为了获得绝缘性良好的铝合金电池外壳,采用硫酸体系,在3003铝合金表面制备了阳极氧化膜并进行了封闭处理。研究了硫酸浓度、温度和时间对氧化膜外观及绝缘性的影响;考察了常温封闭、中温封闭、高温热水封闭对击穿电压及封闭质量的影响。结果显示:氧化膜耐直流击穿电压为1 000 V的最佳工艺:150~170 g/L H2SO4(ρ=1.84 g/cm3),1.0~5.0 g/L Al3+,温度20~25℃,时间50 min,电流密度为1.5 A/dm2;3种封闭均能较大地提高氧化膜的击穿电压,但提高幅度差别不大,高温热水封闭效果低于常温封闭和中温封闭。     

铝及铝合金阳极氧化膜的耐腐蚀性能

铝阳极氧化膜在较强的腐蚀环境中,仍可能发生局部腐蚀、降低其使用寿命.为此,采用极化曲线和交流阻抗法研究了铝及其合金在H2SO4溶液中及添加丙三醇(C3H8O3)后所得阳极氧化膜的耐蚀性,以及氧化膜耐蚀性随电流密度的变化趋势.结果显示:氧化膜随电流密度的增加而增厚,氧化膜厚度的增加有助于增加铝片的交流阻抗值,提高膜的耐蚀性;当电流密度为3.3 A/dm2,在150 mL/L H2SO4中添加9 mL/L丙三醇时,常温下得到的氧化膜均匀致密,交流阻抗值较大,具有较好的耐蚀性.该研究可为合理选材及铝阳极氧化工艺选择提供参考.     

铝合金阳极氧化膜中温封孔工艺

为了提高铝合金阳极氧化膜的封孔质量,研究了中温封孔处理的pH值、时间及温度等参数对封孔质量的影响,采用无硝酸预浸及有硝酸预浸的磷铬酸法对封孔质量进行检测,获得了中温封孔的最佳工艺条件：pH值5．5～6．5,温度不低于52℃,封孔时间不小于1min／μm。     

铝及铝合金宽温硬质阳极氧化工艺应用

铝及铝合金硬质阳极氧化膜 ,除有其功能性的硬度之外 ,还具有很高的抗蚀性 ,尤其在工业大气和海洋气候环境之中。因其转化膜为非晶态结构、孔隙率低、阻挡层厚 ,因而耐腐蚀性强、硬度高、耐磨性好 ,广泛应用于汽车、摩托车及机电产品等零部件。目前 ,在光电产品上也得到应用。我厂采用的宽温硬质阳极氧化工艺 ,一般在常温下进行氧化 ,且比硫酸型和草酸型硬质阳极氧化在溶液维护和操作上更简便。1　工艺及操作条件除油→上挂具→碱蚀 (可不进行 )→水洗→出光→水洗→宽温硬质阳极氧化→水洗→热水封闭→干燥 (烘干或吹干 )→检验。乳酸 (工…     

铝合金阳极化二重封闭工艺的研究EI

本文论述了铝合金阳极氧化二重封闭工艺及封闭膜层的性能，并对二重封闭膜层比重铬酸钾膜层抗蚀能力有明显提高进行了分析。     

缓蚀型添加剂对阳极氧化后铝合金耐蚀性的影响

选择海洋用铝合金进行阳极氧化处理,运用电化学极化及交流阻抗技术,结合微观分析,比较阳极氧化后铝合金的耐蚀性。结果表明,所研究的铝合金中主要存在Al-Cu-Mn-Fe-Si-Cr和Al-Mg-Si第二相,Al-Cu-Mn-Fe-Si-Cr相不溶解,在氧化膜中呈突起状态;而Al-Mg-Si相溶解形成孔洞,易受到侵蚀,成为腐蚀源。对于特定的铝合金,阳极氧化电解液中添加Na2MoO4缓蚀剂后,MoO4^2-进入阳极氧化膜,抑制侵蚀性离子的有害作用,提高了铝合金的耐蚀性。     

硬脂酸封闭工艺参数对铝阳极氧化膜耐蚀性的影响

通过电化学极化和扫描电镜（SEM）形貌观察，研究了硬脂酸封孔工艺中封闭液浓度、温度和时间等参数对铝阳极氧化膜在NaCl溶液中耐蚀性的影响，提出了提高耐蚀性的最佳封孔工艺参数为：90－95℃，100％硬脂酸封闭30min,6%N-甲基烷络丙酮50℃，2min去油膜。结果表明，经硬脂酸封孔后的铝阳极氧化膜表面平整无缺陷，膜的耐蚀性显著提高，在中性NaCl溶液中耐蚀性优于经沸水法和重铬酸钾法封闭的氧化膜。     

全铝车身的发展与探索

本文从全铝车身使用材料的强化及性能特点入手,通过与铜构车身的对比,分析了其优缺点,研究了目前消费现状,指出了发展趋势,做出了市场前景分析。     

Corrosion Behavior of the Rare Earth Sealing Anodized Coating on Aluminum Alloy LY12

Technological process of rare earch sealing anodized LY12 (2024) alloy is introduced.Corrosion behavior of the film was studied by polarization curves and electrochemical impedance spectroscopy (EIS).The results showed that the coating remained passivity at the potential range from the open circuit potential (-780mV) to -250mV in NaCl solution.When the potential exceeded -200mV,corrosion reaction happoened on the coating.the results of EIS analysis was consistent with the results of polarization curves.     

Butt-welding Residual Stress of Heat Treatable Aluminum Alloys

This study, taking three types of aluminum alloys 2024-T351, 6061-T6 and 7075-T6 as experimental materials, conducted single V-groove GTAW （gas tungsten arc welding） butt-welding to analyze and compare the magnitude and differences of residual stress in the three aluminum alloys at different single V-groove angles and in restrained or unrestrained conditions. The results show that the larger the grooving angle of butt joint, the higher the residual tensile stress. Too small grooving angle will lead to dramatic differences due to the amount of welding bead filler metal and pre-set joint geometry. Therefore, only an appropriate grooving angle can reduce residual stress. While welding, weldment in restrained condition will lead to a larger residual stress. Also, a residual stress will arise from the restraint position. The ultimate residual stress of weldment is determined by material yield strength at equilibrium temperature. The higher the yield strength at equilibrium temperature, the higher the material residual stress. Because of its larger thermal conductivity, aluminum alloy test specimens have small temperature differential. Therefore, the residual tensile stress of all materials is lower than their yield strength.     

Distortion Analysis of Single V-groove Butt Welding on Heat Treatable Aluminum Alloys

In this study we conducted single V-groove butt welding (GTAW) on three types of heat treatable aluminum alloys 2024-T351, 6061-T6 and 7075-T6 and compared the angular distortion levels of the three aluminum alloys at different Vee preparation angles with or without restraint. Experimental results demonstrated that when the Vee preparation angle was 0° (I-shaped groove), the angular distortion level of the restrained weldment can exceed that of the unrestrained weldments. Moreover, when the Vee preparation angle was 45°, 60° or 90°, the restrained weldment had lower angular distortion than the unrestrained weldments. The single Vee preparation angle (amount of filler metal) in butt welding affected the angular distortion of the weldment. Without restraint, the angular distortion tended to increase with the single Vee preparation angle. Meanwhile, the angular distortion tended to decrease when the single Vee preparation angle was 60°. Additionally, a restrained weldment had high angular distortion when the single Vee preparation angle was 0°. Notably, the angular distortion tended to reduce with increasing single Vee preparation angle. The angular distortion of the weldment was minimized at an angle of 60°. However, the angular distortion increased when the Vee preparation angle exceeded 60°. The high-temperature yield strength of a material also affected its angular distortion. Angular distortion increased with high-temperature yield strength. Experimental results also showed that, from the strongest to the weakest, the high-temperature yield strength of the three types of aluminum alloys followed the order 6061-T6 and 2024-T351>7075-T6.     

Study on the Rare Earth Sealing Procedure of the Porous film of Anodized 2024 Aluminum Alloy

The rare earth sealing procedure of the porous film of anodized aluminum alloy 2024 was studied with the field emission scanning electron microscope (SEM) and X-ray energy dispersive spectroscopy (EDS),The results show that RE solution can form cerium oxide/hydroxides precipitation in the pores of the anodized coating at the beginning of sealing ,At the same time,the spherical deposits formed on the surface of the anodized coating created a barrier to the precipitation of RE solution in the pores,When the pore-sturctured anodizting film is covered all with the spherical deposits,RE conversion cfoating will form on the surface of the anodized coating,The reaction of the coating formation was investigated by employing cyclic voltammetry ,The results indicate that accelerator H2O2 acts as the source of O2 by carrying chemical reaction in course of coating formation ,In the mean time,it maybe carries electrochemical reaction to generate alkaline condition to accelerate the coating formation,The porous structure of the film is beneficial to the precipitation of the cerium hydroxdies film.     

Effect of Electromagnetic Frequency on Microstructures of Continuous Casting Aluminum Alloys

The relationship between electromagnetic frequency and microstructures of continuous casting aluminum alloys was studied.7075 aluminum alloy ingot of 100 mm in diameter was produced by electromagnetic continuous casting process,the microstructures of as-cast ingot was examined by scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS).The results showed that electromagnetic frequency greatly influenced segregation and microstructures of as-cast ingot,and product quality can be guaranteed by the application of a proper frequency.Electromagnetic frequency plays a significant role in solute redistribution;low frequency is more efficient for promoting solution of alloying elements.