【作者】 李媛乐；

【导师】 关绍康；

【作者基本信息】 郑州大学 ， 材料加工工程， 2010， 硕士

【摘要】 电子铝箔是高端铝箔,主要用于电子工业的重要元器件电解电容器。近年来,随着电子工业的迅猛发展,机电产品的性能和集成度越来越高,这对电子元器件提出了更高的要求——在保证和提高性能的同时有尽量小的体积。因此电解电容器小型化(即实现高比电容)往往是高性能电器产品发展的关键之一。目前,国内高压电子铝箔(即高压箔)的需求量在1.5万吨／年左右,并呈20%的速度逐年递增,而国内能够生产高压箔的厂家却很少,需要大量进口。因此,研究国内外高压箔的组织结构以提高其性能,对我国铝加工产业向更高层次发展,解决高压箔国产化具有重要意义。本文采用SIMS、化学成分分析、SEM、EDS、EBSD、直流电化学腐蚀及力学性能测试等手段,对日本昭和、三菱与国产众和三种成品高压箔中主要杂质元素含量及Fe元素的分布、表面质量、位错坑、晶粒大小、力学性能、立方织构含量及耐电解质腐蚀性进行了对比研究。结果表明：影响高压箔腐蚀化成后比电容的主要因素为杂质元素Fe的含量及其分布、立方织构含量及表面质量。找出了国产与日本成品高压箔存在的差距,并提出了改进措施和建议。对高压箔主要杂质元素含量的对比研究表明：昭和的平均Fe含量最低,为0.0018%；众和的最高,为0.0027%。一般地,Fe含量增加,立方织构会变弱。高压箔中的Fe含量要严格控制在0.0020%以内。而众和的明显偏高,因此需要降低国产众和中的平均Fe含量。日本高压箔中Fe元素沿厚度方向近似呈直线分布,而国产众和却呈曲线分布,且心部有杂质Fe元素的富集。众和中Fe原子在基体中的不均匀分布,导致其高压箔的晶粒粗大、腐蚀不均匀,进而会降低了腐蚀箔的比电容。昭和的平均Si含量最高,为0.0022%；众和的最低,为0.0019%,两者差距较小,Si对立方织构形成过程的负面影响远没有Fe显著。但Si对高压箔性能的影响不是孤立的,还要受到Fe/Si的影响,Fe/Si分别为：昭和最小0.8182；三菱居中0.9047；众和最大为1.4211。两者共存于高纯铝中时,会影响彼此存在的形式,Fe／Si越小则越有利于提高化成箔的比电容。因此Si含量也要严格控制。国产众和高压箔表面起伏及缺陷较多,还存在轧制滚压痕。昭和的平均晶粒为209.1μm,大小适中且晶粒尺寸变化幅度较小；三菱的最小为207.6μm；众和的平均晶粒为223.2μm,尺寸最大且分布紊乱,大小差异较大。昭和在腐蚀后,立方蚀坑最多为17.51%,这与高压箔基体中(001)<100>立方取向有直接的关系。因此,国产高压箔的组织结构控制方面与日本还存在一定的差距,需要改进。三种高压箔的横向抗拉强度和延伸率均高于轧向；其中三菱高压箔的抗拉强度最高,横向28.85MPa,轧向28.30MPa,众和与昭和的抗拉强度相当。高压箔的拉伸试样断口比较平齐,有河流状花样和撕裂岭。不同的位置,硬度存在较小差异,平均硬度日本三菱的最高为17.93HV,众和的最低为16.77HV。原因三菱的晶粒最为细小,根据细晶强化理论,晶粒越小,其抗拉强度和硬度值就越高。因此国产高压箔的在强度方面有待加强。织构对比研究表明：国产众和高压箔在立方织构占有率方面和日本高压箔水平基本相当,两者均可达到国际先进水平(≥95%)。但国产众和的织构含量为96.23%较之日本昭和的97.89%与三菱的97.75%还是稍微低些,且国产众和高压箔中还具有其他的织构取向,如少量的{124}<211>R织构。因此国产箔中应控制非立方织构的含量。通过实验优化出高压箔直流电化学腐蚀工艺参数如下：腐蚀液：HCl+H2SO4混合溶液,HCl取2.0mol/L、H2SO4取0.5mol/L;腐蚀电流密度：0.2A／cm2；腐蚀时间：120S；腐蚀温度：60℃。三种腐蚀箔对比研究表明：日本昭和高压箔520V下化成的比电容最大为0.78μF/cm2,腐蚀孔分布均匀、密度较大且蚀孔较深,总体性能优良；三菱化成箔比电容为0.76μF/cm2;国产众和化成箔比电容最小为0.69μF/cm2,且腐蚀发孔均匀性不好,扩面腐蚀时会出现局部过腐蚀,使得铝箔减薄或穿孔。更多还原

【Abstract】 Electronic aluminum foil is a high-end aluminum foil; it mainly used in the electrolytic capacitor materials which is an important component electronic industry. The performance and integration of mechanical-electrical products are increasing with the rapid development of electronic industry in recent years, which is made of electronic components higher demand-ensuring and improving the performance and simultaneously posses the volume as small as possible. Therefore, Small electrolytic capacitor (That is to achieve high capacitance) is often the key to develop high performance electrical products. At present, the demands of high-voltage aluminum foils are an amount of 1.5 million ton/year at domestic, and were about 20% of the rate of annual increase. But there is few of high-voltage electronic aluminum foil manufacturers in domestic.So it need to import large quantities. Therefore, the study of the gap between domestic and foreign high-voltage electronic aluminum foil and to identify ways to improve its quality are of great significance to develop China’s aluminum industry to a higher level.In this paper, various properties of three kinds of final annealed high-voltage aluminum foils, such as the main impurity elements Fe content and its distribution, surface quality, dislocation pits, grain size, mechanical properties, cube texture and corrosion resistance were comparative studied by means of chemical analysis, SIMS, SEM, EDS, EBSD, DC electrochemical corrosion and mechanical properties testing means. The results showed:the main factors that effect capacitance of etched foil are impurity elements Fe content and its distribution, cube texture and surface quality.We identified the gap between domestic and Japan high-voltage electronic aluminum foils, and proposed improvement measures and recommendations.The comparative studies of content of three main impurity elements in high voltage aluminum foils have shown that:the average Fe content (0.0018%) of Showa is the lowest of the three, and Join world (0.0027%) is the highest. Cube texture becomes weaker with increasing of the Fe content. Therefore, the Fe contents of high voltage aluminum foils need to control in less than 0.0020%. Fe in Japan’s high voltage aluminum foils are approximately linear distribution along the thickness direction, while Join world are curve distribution, and there are enrichment impurities Fe in heart ministry. Fe atoms in Join world and its uneven distribution of the matrix, resulting in high voltage aluminum foil thick grains, uniform corrosion, and thus reduce the capacitance of etched foil. The average Si content of Showa (0.0022%) is highest of the three; Join world (0.0019%) is the lowest, with the small differences. Influence of Si to the formation of cube texture is far from the negative effects of Fe. Influence of Si on aluminum foil is not isolated, but also by Fe/Si. Fe/Si of Showa (0.8182) is smallest; Join world (1.4211) is largest. It will affect their existing format when the two impurities simultaneously in high-pure aluminum, the smaller Fe/Si, the more help to improve the specific capacitance of aluminum foil. Therefore, Si content should be controlled with in 0.0030%.Domestic Join world high voltage aluminum foils possess more surface fluctuations and the defects, There are still rolling roll indentations. The average grain size of Showa is 209.1μm, it is moderate and changed little; Mitsubishi has the minimum grain size (207.6μm); the average grain size of Join world is 223.2μm, it is maximum and distribution is disorder, there are great differences between them. Showa posses the most cubic pits after the electrochemical etched. Which has a direct relationship between (001)<100>cube orientation of the matrix with aluminum foil. Therefore, there is a certain gap between the domestic and Japan product in quality control of the surface with aluminum foil, and it need to improve.Horizontal tensile strength and elongation are higher than the rolling direction in the three kinds of high voltage aluminum foils; in which the tensile strength of Mitsubishi (horizontal tensile strength is 28.85MPa, elongation tensile strength is 28.30MPa) are the highest of the three. Join world and Showa with fairly. Fracture surface of tensile specimen with aluminum foil are fairly flush, there are river-like patterns and tear ridge. There are little differences in hardness at different locations with high voltage aluminum foils. The average hardness of Mitsubishi (17.93HV) is the highest; Join world (16.77HV) is the lowest of the three. The reason is that the grain of Mitsubishi is finest. The smaller the grain, the higher the hardness value according to the fine grain strengthening theory. Therefore, the domestic high voltage aluminum foils need to be strengthened in intensity.Comparative studies of texture showed that:Domestic Join World has almost reached equal level with Japan in volume fraction of cube texture. Both can reach the international advanced level (≥95%), However, texture content in domestic Join World of 96.23% compared to Showa of 97.89% and Mitsubishi of 97.75% is slightly lower, and the domestic Join World has also other texture orientations, such as a small amount of (124)<211>R texture. Therefore, the content of non-cube texture should be controlled in domestic high voltage aluminum foil.The process parameters of DC Electrochemical corrosion with high-voltage electronic aluminum foil through experiment was optimized as follows:etching solution composition:HCl+H2SO4 mixed solution, the concentration of HCl is 2.0mol/L, the concentration of H2SO4 is 0.5mol/L; etching current density: 0.2A/cm; etching time:120S; etching temperature:60 C. Comparative studies of three high voltage aluminum foils showed that:the specific capacitance of Showa is up to 0.78μF/cm2 under 520V. Etched holes of Showa distributed even, larger and deeper, Overall It has excellent performance; the specific capacitance of Mitsubishi formed foil was 0.76μF/cm2; domestic Join World has the smallest specific capacitance 0.69μF/cm2 and fat-hole uniformity of is not good, there will appear local over corrosion making aluminum foil thinning or perforation, because of inequality triggered hole.更多还原