【作者】 邹涛；

【导师】 杜双明；

【作者基本信息】 西安科技大学 ， 材料加工工程， 2010， 硕士

【摘要】 阳极铝箔的扩面腐蚀是提高铝电解电容器电容量的有效方法,但由于扩面腐蚀工艺复杂,铝箔腐蚀孔的低密度和分布的不均匀性制约了其电容量的进一步提高,同时,阳极铝箔较低的抗折弯性能也难以满足电容小型化要求。本文从提高铝电极箔电蚀扩面倍率角度出发,对高压电极箔直流扩面腐蚀进行了研究。采用硫酸-盐酸腐蚀体系对厚度为110μm、99.99%的高纯铝光箔依次进行了预处理、发孔、扩孔等电化学腐蚀实验,采用专用折弯机测试了腐蚀样品的折弯性能,通过SEM分析了腐蚀样片的表面形貌,通过比容测试仪测试了化成试样的比容量,研究了盐酸浓度、电流密度、温度、腐蚀时间等工艺条件对腐蚀铝箔的电容量和折弯性能的影响规律,初步分析高压直流腐蚀的蚀核萌生机制和蚀孔生长机理,取得以下主要成果:铝光箔在65℃、(5g氢氧化钠+1g草酸钠)/ L溶液中经过100秒预处理后,去除了铝箔表面的油污和不均匀氧化层,提高了发孔腐蚀的蚀坑密度和均匀性。同时,经过预处理的扩面腐蚀铝箔具有更高的比容和更小的失重。预处理后的铝箔在2mol/L盐酸和1.5mol/L硫酸组成的腐蚀液中、80℃、0.50 A/cm~2条件下腐蚀140秒后,蚀孔密集且均匀,表现出了良好的发孔腐蚀效果。随着发孔腐蚀液中盐酸浓度的增加,腐蚀试样的比容逐渐增加,当盐酸浓度达到2.0mol/L左右时,比容出现最大值,进一步增加盐酸浓度时,比容开始逐渐下降。经过发孔腐蚀的铝箔在1mol/L的盐酸腐蚀液中、85℃、0.15 A/cm~2条件下扩孔腐蚀600秒,化成520VF后测其比容达到0.73μF/cm2,折弯达到59回次。Cl-浓度的增加提高了高纯铝箔发孔蚀核的萌生几率。高压直流扩孔腐蚀中蚀孔生长存在三种模式:扩张深入式、垂直推进式和分支掘进式,其中垂直推进式可最大限度地提高高压腐蚀铝箔的有效表面积。更多还原

【Abstract】 The surface corrosion of anode aluminum foil is an effective method to increase the capacity of electrolytic capacitors. However, complex process of face expansion, low and inhomogeneity distribution restrict the further increase of electric capacity. Meanwhile, it is also difficult to meet the miniaturization requirements capacitance because of the anode foil’s lower anti-bending performance. So this paper researched on the high voltage direct current electrode foil face expansion corrosion from extending the coverage rate of aluminum foil corrosion.Using sulfate and hydrochloride corrosion system make electrochemical corrosion experiment consist of pretreatment, occur hole and enlarge hole on the 110μm thick, 99.99% high purity aluminum light foil. Tested the bending properties of corrosion samples by special bending machine, analysesed the surface of corrosion samples by SEM, tested the sample capacity by specific volume test machine,researched on the influence of hydrochloride density, current density, temperature and corrosion time to electric capacity and bending properties of corrosion aluminum foil. Achieve the following main results:The aluminum foil can remove surface oil effectively , form a homogeneous porous oxide film, increase the wettability of aluminum foil surface which corrosion liquid etching on in the process, improve the density and uniformity of creating hole after pretreatment at 120 seconds, 60℃and （5g NaOH +1 g Na₂C₂O₄）/L solution. Meanwhile, etching of extending surface area aluminum foil has higher specific capacitance and less weight loss after pretreating.SEM analysis showed that aluminum foil corrosion hole is density and uniform, showing good creating hole etching effect after pretreatment at 2mol/L HCl ,1.5mol/L H₂SO₄ mixture, 80℃, 0.50 A/cm² current density and 140 seconds. The specific capacitance of aluminum foil can attain 0.73μF/cm² and bending reach up to 59 times after creating hole corrosion in 1mol/L HCl etching solutions, the current density of 85℃and 0.15 A/cm² at 600 seconds.Preliminary analysised the mechanism of loss initiation and pit growth of high voltage direct current corrosion. which increased Cl-concentration can increase the probability of corrosion initiation.Made the density of initial corrosion hole increase gradually with the increasing time of creating hole. The vertical push of enlarging hole corrosion can increase the effective surface area of high high voltage corrosive aluminum foil maximum.更多还原