交流阻抗法在表面處理後之G2鈦金屬的研究

Impedance studies on the surface treated G2 titanium

賴舜仁(Shun-Jen Lai)

指導教授 ： 薛文景

國立臺北科技大學/工程學院/材料科學與工程研究所/碩士(2008年)

摘要

電化學交流阻抗法(EIS)常被應用於觀測塗層的腐蝕防護特性，而鈦金屬及鈦合金在航空及醫療工業正如火如荼的被應用，所以抗腐蝕能力的提升是未來工業發展的重點。本研究先利用電解拋光將試片達到一致的粗糙度，再分別以不同的化學轉化處理試片表面，讓鈦金屬表面形成化成皮膜，來提高鈦金屬表面的抗腐蝕能力。經實驗證明使用商業用G2純鈦，將經各種化學轉化處理後的試片浸漬3.5 wt% NaCl溶液(人工海水)兩周，其總阻抗明顯高於電解拋光，並可以由SEM觀察到試片在浸漬前後表面並沒有明顯的改變，而使用EIS觀察Bode及Nyquist圖可比較隨著浸漬時間增加抗腐蝕能力的變化，再由Zview模擬出等效電路圖，並分析等效電路圖中的元件數值隨著時間的變化來解釋試片表面現象。

關鍵字

交流阻抗 ； G2鈦金屬 ； 陽極氧化 ； 化學轉化

並列摘要

Commercials purity titanium (Grade 2) is a working-horse material in the aerospace industries and medical implants. It has been an increasing demand in brightened and polished surfaces of G2 titanium products with complex shape, which may be achieved by the converting techniques. Passive film formed on the surfaces of G2 titanium by phosphate conversion and followed with 60 volt of anodizing in 1N hydro-phosphate electrolyte. The purpose of this work is to study the passivity effects on the chemical converting and anodizing treated G2 titanium. Charge transfer and mass transport in the chemical conversion and anodizing process are observed through electrochemical impedance spectroscopy (EIS) method in 3.5 wt% sodium chloride (NaCl) solution. The impedance spectra over the Bode and Nyquist diagrams are successfully modeled on the electric equivalent circuit.

並列關鍵字

electrochemical impedance spectroscopy ； chemical conversion ； anodic treatment ； commercials purity titanium (Grade 2)

參考文獻

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