鋁箔之晶粒大小和集合組織對電蝕性質的影響

Effect of Grain Size and Texture on the Capacitance of Etched Aluminum Foils

鋁電解電容器中使用鋁箔作為其陽極箔與陰極箔材料，為了使電容量提昇，腐蝕技術被應用於擴大鋁箔之有效表面積。其中陽極箔需具有耐壓性質，因此採用純度99.98%以上之高純度鋁素箔，而鋁箔的一些冶金性質會影響電蝕之效果。本研究即在探討硬質陽極素箔經退火處理後，其晶粒大小及晶面對電蝕之影響，以瞭解材料與腐蝕技術彼此間之關係。硬箔經過退火後，其晶粒大小在相同的退火時間下隨著退火溫度之提高而增大，最大可達230 µm。對退火箔而言，晶粒越大則比電容越高，且此現象不因酸度不同而異。對退火箔而言，{100}強度大則比電容越高，此與晶粒大小之影響相似。晶粒大小與晶面對電蝕的影響十分相似，事實上兩者有非常一致的相依關係。

Etched aluminum foils are used as the anodic and cathodic foils in the aluminum electrolytic capacitors because of their high effective surface. To get good voltage resistance, highly pure (over 99.98%) aluminum plain foils are adopted as the materials for anodic foils. The microstructure of the foil is one of the major factors affecting the electrolytic properties. The grain size and texture of annealed foils and their effects on the capacitance were studied. The grain size was found to increase with the annealing temperature under the constant soaking time. The capacitance of the etched foil is enhanced by the increasing grain size. This is true for different acid concentrations. The capacitance is also improved by the intensity of {100}, which is also increased with temperature. The influence of these two important factors is related.