鎂合金AZ61釩酸鹽陽極處理耐蝕性能之研究

Studying Vanadate Anodizing Bath of AZ61 Magnesium Alloy for Corrosion Resistance

楊光絢(K. H. Yang) ； 程偉堃(W. K. Chen) ； 葛明德(M. D. Ger) ； 劉豫川(Y. C. Liu)

《界面科學會誌》 27卷3&4期 (2005/09) Pp. 163-172

https://doi.org/10.30020/JCCIS.200509.0002

摘要

本研究主要探討在氫氧化鉀70g/ l與磷酸三鈉20 g/ l混合液中添加不同釩酸鹽濃度，對鎂合金（AZ61）施以陽極處理其陽極膜耐蝕性之影響。由電化學直流分析法極化曲線與交流阻抗頻譜（Electrochemical Impedance Spectroscopy, EIS）分析顯示，隨釩酸鹽添加量之增加，陽極膜之腐蝕電流降低，而交流阻抗值增大，當添加釩酸鹽為30g／l時阻抗可由100k增加至350k ohm／cm^2。陽極膜分別以SEM表面微結構觀察、EDX元素分析及膜厚測定，結果發現當釩酸鹽添加量增加時，陽極膜中類似島狀燒結氧化物形貌更趨明顯、釩之含量及膜厚亦隨之增加。綜合以上實驗結果顯示陽極處理液中添加釩酸鹽將有助於陽極膜之成長、抑制火花之產生並有效提高其耐蝕性。

關鍵字

鎂合金 ； 陽極處理 ； 耐蝕性 ； 極化曲線 ； 電化學交流阻抗頻譜（EIS）分析

並列摘要

The relationship of the anodizing film of the Magnesium alloy (AZ61) and erosion resist with under Sodium Hydroxide, 70g/ l, and Sodium Phosphate, 20g/ l, by adding various concentration of Vanadate solution was investigated. According to the measurement datum of polarity curve and Electrochemical Impedance Spectroscopy, EIS, with the increasing of the amount of the vanadate, the decreasing of the erosion current and coupling with the increasing of the electrochemical impedance values. The resist will increase from 100K ohm/cm to 350K ohm/cm when the concentration of vanadate up to 30g/ l. The surface of the anodizing film was observed by SEM and found that with the increasing of the vanadate concentration, the more clear of the appearance of the island-like oxidant. Meanwhile, EDX was also proved that with the increasing of the vanadate concentration, the increasing of the vanadate content of the film was found. Thickness of the film was measured by thickness measurement instrument and found that with the increasing of the vanadate concentration, the increasing of thickness of the film. The thickness growth rate increased instantly when the vanadate concentration up to 30g/ l. According to the above experimental results, anodizing bath with adding vanadate solution will benefit for the growth of the anodizing film and inhibit the sparking and further to improve the erosion resist.

並列關鍵字

Magnesium alloy ； anodizing treatment ； erosion resist ； polarity curve ； electrochemical impedance spectroscopy