退火工艺对低压铝箔氧化膜和比电容的影响  

Effect of annealing technology on oxide film and specific capacity of aluminum foils for low voltage electrolytic capacitors

作　　者：吕亚平[1] 毛卫民[1] 何业东[1] 杨宏[1] 

机构地区：[1]北京科技大学材料学院,北京100083

出　　处：《材料热处理学报》2007年第5期78-81,共4页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(50571020);教育部博士点基金(20040008010)

摘　　要：纯度99.988%的铝箔在300,400和500℃分别进行0.5,1和2h真空退火,然后利用电容法,间接测出退火箔的氧化膜厚度。用扫描电子显微镜观察部分退火箔的腐蚀形貌,测出相应的比电容。结果表明,在400℃退火时,铝箔的氧化膜厚度最小,300℃居中,500℃最大。在300℃退火时,随着保温时间的延长,铝箔的氧化膜厚度减小;而在400℃和500℃退火时,氧化膜厚度增大。500℃退火的铝箔,表面微量元素的分布接近于平衡状态,分布较均匀,铝箔表面腐蚀孔坑较细小,蚀坑密度大,比电容较高。而低温退火的箔样,微量元素偏聚在铝箔表面的位错露头附近,使铝箔表面出现大量的腐蚀孔坑,降低了比电容。The thickness of oxide film of aluminum foils which were annealed at 300℃ ,400℃ ,and 500℃ for 0.5h, lh and 2h respectively was measured by means of capacity method and the surface corrosion morphology was observed under scanning electron microscope. The specific capacity of etching foils was also surveyed. The results show that among the aluminum foils annealed at 300℃ ,400℃ ,500℃ ,the oxide film of the aluminum foil annealed at 400℃ is the thinnest. Furthermore, annealed at 300℃ ,the thickness of oxide film of the aluminum foil decreases with increasing annealing time and the thickness of oxide film increases with time when the foil is annealed at 400℃ and 500℃. The trace elements in the surface of aluminum foils annealed at 500℃ are almost in the equilibrium state and the distribution is nearly uniform, which cause tiny etching pits and increase specific capacity. The trace elements accumulated around the dislocation when the aluminum foil is annealed at lower temperature and the non-uniform distribution can increase the size of etching pits and reduce the specific capacity.

关 键 词：铝箔 氧化膜 腐蚀 扩散 

分 类 号：TG166.3[金属学及工艺—热处理]