Distribution of Microelements and Their Influence on the Corrosion Behavior of Aluminum Foil

The distribution of microelement Fe, Si, Cu and Mg in the surface layer of aluminum foil annealed at 300℃ and 500℃ were determined by secondary ion mass spectrometer. The corrosion structure produced by electrochemical etching was also observed. It was found that the Mg concentration at external surface was increased exponentially over the fourth degree and promoted by higher annealing temperature, which will increase the number of corrosion pits inside the large grains, and therefore the specific capacity of the foils for electrolytic capacitors. The similar effects of microelement Fe, Si and Cu were not so strong.

Effect of tunnel structure on the specific capacitance of etched aluminum foil

The morphology of etched aluminum foil was observed using scanning electron microscopy, which led to the establishment of a cylindrical model and two merged models, considering the fixed weight loss of etching. The maximum of specific capacitance and the cor- responding optimum values for tunnel sizes at various anodization voltages were predicted. The increased size distribution and taper of tun- nels were demonstrated to decrease the specific capacitance, whereas the addition of polymeric additive into the ttmnel widening solution was demonstrated to increase the capacitance. The formation of merged tunnels on the etched aluminum surface, irrespective of the presence of row-merged tunnels or cluster-merged tunnels, resulted in a dramatic decrease in the specific capacitance. It is concluded that, enhancing the uniformity of turmel size and distribution and avoiding the formation of merged tunnels are the effective approach to achieving the higher capacitance for the tunnel etched and formed aluminum foil.

Effect of cerium addition on microstructure and texture of aluminum foil for electrolytic capacitors

Anode foil of aluminum electrolytic capacitor,which requires large surface area for high capacitance,were prepared by rolling,annealing and electrochemical etching.Effects of cerium addition on the capacitance of aluminum electrolytic capacitors were investigated.Microstructure of the aluminum foil surface was observed by optical microscopy(OM) and scanning electron microscopy(SEM).Electron back scattered diffraction(EBSD) was also employed to reveal texture evolvement of cold-rolled aluminum foil after ann...

Effect of Trace Sn on Pitting Behaviors of High Voltage Anode Aluminum Foil

The effect of trace Sn on the pitting morphology of high voltage anode aluminum foils was investigated. The distributions of microelement Sn, Fe, Si, Cu and Mg in the surface layer of aluminum foils with different Sn content were determined by using a secondary ion mass spectrometer. It was found that the micro-alloyed Sn is enriched at the external surface. The mechanism of pitting behavior of trace Sn on aluminum surface is similar with that of lead. Enrichment of Sn in the surface layer provides large numbers of sites for initiation of pitting corrosion, while pitting sites appeared relatively inhomogenously in the foils without Sn. Sn, as an eco-friendly microelement, can be applied to replace Pb in improving the homogenous pitting behaviors of high voltage aluminum foils, in which the volume fraction of cube texture is not reduced.

Ultrafine microstructure and texture evolution of aluminum foil by asymmetric rolling

AA1060 aluminum foil was rolled from 4 mm to 20 μm by asymmetric rolling without intermediate annealing. The microstructures and textures were investigated. The original coarse grains with an average grain size of 60 μm were refined to fine equiaxed grains with an average grain size of about 500 nm with mainly large grain boundaries. During the rolling, the intensities of copper texture C-{112}<111> and brass texture B-{011}<211> gradually increased, and most crystallites aggregated along the β and τ orientation lines. The orientation intensity reached the maximum value 26 when the foil was rolled to 500 μm, but significantly decreased to 16 when the thickness became 20 μm, and the texture mainly consisted of a rotation cubic texture RC-{100}<011>. With the combined forces including drawing, compressing and shearing, severe plastic deformation was obtained during the asymmetric rolling, promoting dynamic recrystallization at room temperature. Because of a combined force in the deformation zone and shear force along the normal direction, dynamic recrystallization occurs during the asymmetric rolling; therefore, the average grain size is significantly refined. The texture intensity of ultrathin strip first increases, i.e., work hardening, and then decreases mainly because of dynamic recrystallization.

Icephobic performance on the aluminum foil-based micro-/nanostructured surface

The research of superhydrophobic materials has attracted many researchers＇ attention due to its application value and prospects.In order to expand the serviceable range,people have investigated various superhydrophobic materials.The simple and easy preparation method has become the focus for superhydrophobic materials.In this paper,we present a program for preparing a rough surface on an aluminum foil,which possesses excellent hydrophobic properties after the treatment with low surface energy materials at high vacuum.The resulting contact angle is larger than 160° and the droplet cannot freeze on the surface above-10 ℃.Meanwhile,the modified aluminum foil with the thickness of less than 100 μm can be used as an ideal flexible applied material for superhydrophobicity/anti-icing.

Effects of HNO_3 concentration on the pit morphologies of aluminum foil etched in HNO_3–HCl and HNO_3–H_2SO_4–HCl solutions

In this work, the effects of HNO3 concentration on the pit morphologies of high-cubic-texture aluminum foil etched in HNO3-HCl and HNO3-H2SO4-HCl solutions were investigated. When the aluminum foil was etched in HNO3-HCl solutions, the morphologies of pits transformed from irregular tunnels to typical tunnels （as inverted pyramids） and shallow cuboids as the HNO3 concentration in the etchant solution was increased. However, as the HCl concentration in the etchant solution was increased, the morphologies of pits transformed from shallow cuboids to typical tunnels （as inverted pyramids） and irregular tunnels. When the aluminum foil was etched in n N HNO3-（7.2-n） N H2SO4-0.8 N HCl solutions, the morphologies of the pits transformed from typical tunnels （i.e., the number of sub-tunnels formed on the main tunnels increased） to irregular tunnels （corrugated tnnnels and polyline tunnels） as the HNO3 concentration in the etchant solution was increased. These effects are attributed primarily to corrosion on the （100） and （010） faces of pits being accelerated and to the （001） faces be- ing prone to passivation to different degrees when various concentrations of HNO3 are added to the etchant solutions.

ANALYSIS OF ROLL SYSTEM STABILITY ABOUT ALUMINUM FOIL MILLS

To improve roll system stability of aluminum foil mills, roll system stability of 2200 highspeed aluminum foil mill is analyzed with energy stable method. Two different restrictive conditions which gaps between chock of work roll and window of stand whether exist or not, are studied respectively. A new concept of roll system with open /closed compound pair conies up with as well for re-newably synthesizing restrictive mechanism of aluminum foil mills' chock. Through these studies, the conflict, whether reserving the gap for the roller replacement or eliminating the gap for roller's normal work, is successfully settled. This concept and analyzed result give the actual mechanism with open/closed compound restriction and the method of realizing high-speed rolling and prolonging longevity of end thrust bearing on work roll. It has important theoretical meaning and engineering value for modern technical reform of aluminum foil mills and plate strip mills.

Effect of trace Sn on corrosion behaviors of high voltage anode aluminum foil

The cube texture and the surface corrosion structure of aluminum anode foil for high voltage electrolytic capacitor containing trace Sn were investigated based on quantitative texture analysis and microstructure observation under SEM. High volume fraction of cube texture over 95% and obviously higher specific capacity are obtained in the foils with less than 0.002% Sn. It is indicated that the corrosion behavior of trace Sn on aluminum surface is similar with that of Pb. Higher content of Sn over 0.002% reduces the cube texture component and therefore the specific capacity. Sn, as an eco-friendly microelement, can be applied to replace Pb in improving the homogenous pitting behaviors of high voltage aluminum foils.

Purification of scrap aluminum foil and aluminum melt covering and protecting & atomic purification theory

A new flux, JDN I, including rare earth compounds, for purification of the scraps of 99.99% aluminum foil was introduced. The experimental results indicate that its function of degassing and deoxidizing is excellent. The hydrogen content of the scrap aluminum foil melt purified by JDN I flux decreases greatly from 4.5 mL/kg to 1.2 mL/kg at 720 ℃. The tensile strength of the samples refined with JDN I flux increases by 19.2% and the elongation increases by 38.3% in comparison with those without flux. The purification mechanism of JDN I was discussed and a theory of covering, protecting & atomic purification was also put forward.

Mechanism of strengthening of cube texture for high purity aluminum foils by additional-annealing

The mechanism of strengthening of cube texture ({001}<100>) by additional annealing of high purity aluminum foils was investigated by using orientation distribution functions (ODFs) and electron back scattered diffraction (EBSD). The results of ODFs and fiber show that the orientation densities of the S {123}<634> and Cu {112}<111> components increase in both the additional annealed samples and the 0.11 mm final cold rolled foils. And the EBSD results demonstrate that cube nuclei can be identified in the deformed matrix of those additional annealed samples. It is suggested that the strengthening of cube texture can be brought out by the increasing of components of S and Cu and the formation of cube nuclei caused by additional annealing. Moreover, it is found that the cube texture increases first and then decreases with increasing additional annealing temperature, and it is the strongest at 180 ℃.The strengthening of cube texture by additional annealing is proposed as the result of oriented growth of cube subgrains.

NUMERICAL SIMULATION FOR WIDE MAGNITUDE AND HIGH SPEED ALUMINUM FOIL MILL

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Evolution of recrystallization textures in high voltage aluminum capacitor foils

The evolution of recrystallization textures in high voltage aluminum capacitor foils which are produced with a high level of cold reduction was tracked by analysis of microstructure and crystallographic texture. The results show that the deformation textures are mainly composed of S orientation, Cu orientation and a little B s orientation. During the low temperature stages of final annealing, the iron precipitates first along the sub grain boundaries, and the Fe concentration in the matrix becomes low. Then, the cube grains nucleate preferably into the sub grains. At high temperature stages, the cube nuclei can grow preferably because of their 40°<111> orientation relationship to the S orientation, the main component of the rolling texture. Finally, the cube texture is sharply strong and the R orientation is very weak in the foils.

Simple and Rapid Spectrophotometric Determination of Titanium on Etched Aluminum Foils

Introduction of titanium oxides with high permittivity on etched aluminum foils’ surface has been successfully utilized to increase specific capacitance of anode foils for aluminum electrolytic capacitors. In order to quantify the concentration of titanium (IV) on the etched aluminum foil precisely, a simple and rapid spectrophotometric procedure has been developed. After optimizing a series of variables including absorbance wavelength, concentration of nitric acid, concentration of hydrogen peroxide, nitration time and developing time, analytical precision and accuracy were tested by using standard working solution containing known amount of titanium (IV). The results showed that Lambert-Beer’s law was obeyed in the range of 0.01 to 3.00 mmol·L﹣1. The relative standard deviation (RSD) ranged from 0.67% to 1.09% (n = 6), and the recovery was between 99.17% - 100.03%. Investigation on effect of Al3+ ion indicated that there was no interference in the absorbance of titanium (IV) at 410 nm. The proposed procedure was applied to real samples for the determination of titanium (IV), and the results were in a good agreement with the values certified by inductively coupled plasma-atomic emission spectrometry (ICP-AES).

Effects of rolling technical factors on microstructures and mechanical properties of aluminum foils

The effects of rolling driving methods and technical factors on the microstructures and mechanical properties of aluminum foils based on the industrial trials were studied by TEM, tensile test and texture analysis. The results show that there exist obvious dynamic recovery and primary location re crystallization phenomena in the aluminum foils during high speed rolling. Meanwhile the phenomena become more obvious as the rolling speed or the reduction increases, especially in the asymmetrical rolling process with single roller driving, the dynamic primary location recrystallization is more likely to come into being. The effects of the dynamic recovery phenomena and the dynamic primary location recrystallization on the comprehensive final product ratio and the quality of aluminum foils were discussed.

Cu对铝/钢CMT熔钎焊接头界面区组织的影响研究

采用冷金属过渡方法,以AlSi5焊丝为填充金属,在5052铝合金和镀锌钢板之间添加铜箔片进行搭接熔钎焊,使用扫描电子显微镜结合能谱分析和拉伸试验机对接头的界面区组织与性能进行研究。结果表明,未加入铜箔时,界面区组织主要由FeAl_(3)金属间化合物组成;铜箔的加入使得界面区组织中新生成了CuAl_(2)金属间化合物,同时改善了Zn在界面区的分布。Zn固溶于Al中,一定程度上抑制了Fe-Al金属间化合物产生。加入铜箔后的试样断裂位置发生改变,接头的承载能力与未加入铜箔的相近。

高质量双零铝箔生产常见问题分析

简述了国内高质量双零铝箔生产状况,并对双零铝箔生产中影响产品质量的因素,如铝箔坯料质量、生产工艺选择、人员操作施工等进行了分析,从铝箔坯料控制、轧制工艺选择、轧制油选配、热处理工艺、工作环境及相对湿度等方面,探讨了如何降低针孔数量,减少双零铝箔轧制的废品率,旨在提高国内双零铝箔产品质量。

不同真空包装材料对酱肉产品理化及微生物性质的影响

为研究不同包装材料对酱肉贮藏期间品质的影响,以聚酯/铝/聚乙烯(PET/AL/PE)铝箔和聚酯/聚乙烯(PET/PE)透明薄膜为包装材料,对四川酱肉进行真空包装,测定酱肉在常温贮藏过程中水分活度、过氧化值、丙二醛含量、pH值、亚硝酸盐含量、色泽、质构特性及菌落总数的变化。结果表明,真空铝箔包装相较于真空透明包装可延缓酱肉脂质的氧化并加快亚硝酸盐的降解,对维持酱肉的硬度、弹性、咀嚼性和内聚性有显著效果,并对抑制微生物的繁殖有显著作用。

YB45型细支硬盒包装机加速辊组件弹性销轴的设计

【目的】解决YB45型细支硬盒包装机加速辊内、外端橡胶辊压力调节不均匀,导致单张铝箔纸输送过程中歪斜的问题。【方法】设计制作了一种两段式弹性销轴,能够实现加速辊内、外端橡胶辊压力的均匀调节,保证单张铝箔纸的平稳输送。【结果】因单张铝箔纸输送过程中歪斜而被剔除的烟包数量由73.8盒/班,降低为1.2盒/班,降低了98.4%。机台效率由改进前的89.2%,提升为90.5%,提升了1.30%;产品质量得分由改造前的98.4分,提升为99.0分,提升了0.61%。【结论】弹性销轴为行业首创,它的使用,有效地解决了YB45型硬盒包装机加速辊内、外端橡胶辊压力调节不均匀,导致单张铝箔纸输送过程中歪斜的问题,提高了机台效率,保障了铝箔纸包装质量。

1235铝合金冷加工过程中组织演变

为进一步掌握铝箔坯料在冷加工过程中的组织演变规律,以1235铝合金双零箔坯料为研究对象,探究其7.0 mm厚铸轧坯料冷轧至3.8,1.8,0.9,0.5 mm过程中第二相形貌、尺寸的变化情况。结果表明,铸轧坯料冷轧一道次后均匀化退火未改变第二相的属性,只是在一定程度上改变了相的尺寸,组织内的θ相(FeAl_(3))会发生溶解和均匀化扩散,且在高温下部分θ析出相形貌发生了变化,长大变成针状;后在一道次冷轧至1.8 mm过程中针状相发生了明显的“折断”,但在随后的冷轧过程中,针状相被破碎至5~8μm范围内以后再很难被进一步破碎,验证了针状第二相“硬而脆”的特性,说明在退火过程中控制尺寸>5μm第二相的数量的重要性。