aluminum-anodizing Rev.C阳极处理.ppt

Anodizing of Aluminum Physical property of pure Aluminum 物理性質 item property Chemical symbol 元素符號 Al Atomic weight 原子量 26.97 Atomic number 原子序 13 Specific gravity 比重 2.70 (20℃) Dissolving point 熔點 658℃ Boiling point 沸點 2057℃ Dissolving latent heat(cal/g) 熔解熱 94.55 Vaporization latent heat(cal/g) 汽化熱 about 2,000 property of pure Aluminum純鋁的特性 兩性金屬,化學性活潑易於空氣中生成氧化物,氧化鋁可阻止繼續氧化,鋁純度愈高膜層愈均勻,耐蝕性愈佳。 對還原劑易起做用.但對氧化劑則有耐蝕功能.純鋁在濃硝酸下呈鈍態. 比重輕,為地球表面存在最高之金屬,且表面處理形態多樣化,工業廣為應用. 導電率約為銅的60%.熱傳導率為銅的1/2鐵的3倍. Definition Anodizing is the successful development and control of a natural oxidation process that occurs when aluminum is exposed to the atmosphere. Electricity and chemicals are used jointly to produce a hard, transparent surface that is integral with base Aluminum. 鋁於大氣環境下即會產生一層氧化皮膜.鋁底材接陽極電流於電解液中產生一層硬而透明的表面, 此電化學反應稱之為”陽極處理” Characteristics陽極處理的特性 Hard, comparable to a sapphire (藍寶石) Transparent, similar to glass (透明,接近玻璃) Insulative and static-resistant (絕緣,防靜電) Wide variety of colors and finishes (顏色外觀多變) Integral with Aluminum surfaces, non-flaking (與鋁表面完全結合且不碎裂) Physical property of Aluminum anodizing陽極處理的物理性質 Porosity density 陽極孔密度 6x1010/cm2 Coefficient of thermal conductivity 0.16cal/cm.sec. ℃ 熱傳導係數 Electrical resistance 電阻 12~13MΩ-cm Potential resistance 耐電壓 400V Film thickness 膜厚 5~20μm(normal) ,30~100μm(hard anodizing) Porosity ratio 孔隙率 20~30%