https://scholars.lib.ntu.edu.tw/handle/123456789/74828
Title: | 改善鋁箔蝕孔密度與均勻性之電源波形設計 | Authors: | 林招松 | Keywords: | 動態循環伏安法;化學能譜儀;競爭吸附;低壓陽極鋁箔;galvanodynamic polarization curve;X-ray photoelectron spectra;competitive adsorption;aluminum foils for low-voltage electrolytic capacitor | Issue Date: | 2005 | Publisher: | 臺北市:國立臺灣大學材料科學與工程學系暨研究所 | Abstract: | 本研究於鹽酸溶液中探討電源波形及硫酸根對低壓陽極鋁箔交流電蝕之孔蝕行為的影響。利用動態循環伏安法(GVP)量測試片 表面反應電壓對應電流和週期數的關係,以掃描式電子顯微鏡(SEM)觀察鋁箔表面形貌和橫截面蝕孔蝕孔形狀,並加以統計線密度、穿蝕深度。使用穿透式電子顯微鏡(TEM) 觀察橫截面試片,分析蝕孔內部微結構,進ㄧ步使用化學能譜儀(XPS)分析表面鍵結狀況。 研究結果顯示方波為電蝕較有效率之波形,電蝕後穿蝕深度最深、表面蝕孔較大、溶蝕量較多、表面腐蝕生成物較厚等特點。 由電化學量測可得知其單一電量和累積電量比三角波和正弦波多。鹽酸電解液中添加適量硫酸根導致蝕孔穿蝕深度變小,使蝕孔細緻均勻,減少表層未具蝕孔鋁掉落的機率,且由XPS 結果發現增加硫酸根造成的表層吸附硫酸根的量增加,使得氯離子因競爭吸附而導致蝕孔大小及穿蝕模式改變。對此結果歸納整理並提出合理機制。 The effects of current waveforms and sulfate ions on pitting behavior of aluminum foils for low-voltage electrolytic capacitor were investigated during etching in hydrochloric acid. During the course of etching, the galvanodynamic polarization curve was recorded, in which the breakdown potential was measured. A scanning electron microscope was employed for characterizing the surface morphology and cross section of the foil, including the average depth and linear density of the pits. Cross-sectional transmission electron microscope specimens were prepared from the as-etched foil to reveal the detailed pit morphology and etch film structure. Finally, X-ray photoelectron spectra of the surface film on the as-etched foil were measured using an ESCA250 (VG Science Inc., UK) spectrometer with monochromatic Mg K radiation. Experimental results indicate that compared with the triangular and sinusoidal waveforms, etching with the square current waveform resulted in larger and deeper pits, thicker etch films, and more weight lost during etching. This is due to the more charge imposed in each anodic half-cycle associated with the square waveform. The presence of sulfate ions in hydrochloric acid led to the formation of finer, uniformly-distributed and shallower pits; thereby, reducing the loss of aluminum due to undermining by the cubic pits. The effect of sulfate ions on the pitting behavior was presumably due to competitive adsorption of sulfate ions with chloride ions, as shown by XPS analysis. |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/12493 | Other Identifiers: | 932216E002020 | Rights: | 國立臺灣大學材料科學與工程學系暨研究所 |
Appears in Collections: | 材料科學與工程學系 |
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932216E002020.pdf | 464.29 kB | Adobe PDF | View/Open |
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