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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/2255

    Title: 鋁在酸性溶液中孔蝕行為研究;Pitting Behavior of Aluminum in Acid Solution
    Authors: 張志雄;Chih-Hsiung Chang
    Contributors: 機械工程研究所
    Keywords: 電化學量測;;孔洞蝕刻;掃描式電子顯微鏡;pitting;Aluminum;GVP;SEM;electrochemical measurement
    Date: 2003-06-25
    Issue Date: 2009-09-21 11:42:03 (UTC+8)
    Publisher: 國立中央大學圖書館
    Abstract: 本研究主要是探討高純度鋁(99.95%),在8N鹽酸(HCl)溶液中,進行交流電(三角波)蝕刻的孔蝕行為。利用電化學量測方法:定電流循環極化法(GVP),輸入三角波電流(0.15 A/cm2),量測表面的電壓變化,來推測金屬與溶液界面的電化學反應。並利用掃描式電子顯微鏡(SEM),觀察電化學蝕刻後的表面形態。對於蝕刻後表面的化學成分,則利用化學分析電子術(ESCA)分析表面化學生成物,探討表面狀態的不同,對表面腐蝕行為的影響。 從改變各種參數的實驗結果,發現增加交流電頻率,會使破裂電壓(Eb)上升(0.093 V?0.32 V),蝕孔(pit)變小,並造成表面局部性蝕刻。添加氧化劑(H2SO4),會產生局佈性孔洞蝕刻,破裂電壓(Eb)會隨濃度增加而上升,但添加較高濃度氧化劑(>0.3 N)時,在陽極半反應所產生的尖峰,會偏移至陰極半反應。由ESCA能譜圖分析,可推論得知:陰極半反應中產生尖峰,是由於較厚的陽極鈍化膜(Al2O3),導致陰極反應的電位升高。 Pitting behavior of pure aluminum foils (99.95%) in hydrochloric solution performed at constant alternating current was investigated. A diagram of V-I diagram was plotted from the galvanodynamic voltammetry polarization (GVP) of the aluminum foil in the acid solution. Corrosion morphology of the aluminum foil was examined through scanning electron microscope (SEM). The relationship between the corrosion morphology and the corresponding profile of V-I diagram for the aluminum foil was of interest. Morphology examination revealed that the size of pits and the portion of pitting area decrease markedly with increasing the frequency of the alternating current. Analyzing in the V-I diagram, we found that the breakdown potential(Eb)with its corresponding current density decrease with increasing the ac frequency. The effect of additives indicated that an addition of sulfuric acid in the electrolyte results to intensify the size difference of pits, thus size distribution becoming less homogeneous. The addition of aluminum chloride (AlCl3) in the electrolyte only intensified the pitting corrosion when ac with high frequencies ( > 60 Hz) was applied.
    Appears in Collections:[機械工程研究所] 博碩士論文

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