AZ31鎂合金鈦酸鹽化成處理

A Titaniurn Conversion Coating Process for AZ31 Magnesiurn Alloys

楊育銓(Yu-Chuan Yang) ； 蔡承洋(Cheng-Yang Tsai) ； 林招松(Chao-Sung Lin)

《防蝕工程》 25卷4期 (2011/12) Pp. 211-218

https://doi.org/10.6376/JCCE.201112.0035

摘要

鈦酸鹽化成處理可有效提升鎂合金之抗蝕性，其化成皮膜均勻，外觀呈現灰白色，保有些許底材之金屬光澤。本研究以微結構與電化學之分析，探討鈦酸鹽化成皮膜之成長與抗蝕性質，以期建立化成反應機構。本實驗自OCP曲線中選取0.5，1，3，6，10分鐘等五個不同的化成時間，以SEM觀察皮膜的衍生與成長，輔以TEM橫截面的微結構觀察，分析皮膜結構，結果顯示鈦酸i鹽化成皮膜相當緻密、均勻，厚度約為300 nm。經24小時鹽霧試驗，鈦酸鹽化成處理後之試片具有較佳之抗蝕性，腐蝕受釗明顯抑制。另外，極化曲線與交流阻抗等電化學分析，亦顯示出鈦酸鹽化成皮膜優異之抗蝕性。綜合上述分析，化成6分鐘之試片具有最佳的抗蝕能力。

關鍵字

AZ31鎂合金 ； 鈦酸鹽化成處理 ； 交流阻抗 ； 抗蝕性

並列摘要

The process of titanium conversion coating can efficiently promote the corrosion resistance of magnesium alloys. This study investigated the growth behavior and corrosion resistance mechanism of titanium conversion coatings via microstructural and the electrochemical analyses based upon an open circuit potential (OCP) measurement, five specimens with different immersion times of 0.5, 1, 3, 6, and 10 min were selected. The surface morphology of the coating was observed by SEM. A detailed cross-sectional morphology was explored using TEM. The corrosion resistance of the titanium conversion coating was measured via electrochemical analyses, such as polarization curves and electrochemical impedance spectroscopy (E IS). The results indicated the titanium conversion coating was uniform and dense, and the thickness was around 300 nm. The specimen treated with the titanium conversion coating process showed a better corrosion resistance than the as-received magnesium substrate after a 24-hour salt spray test.

並列關鍵字

AZ31 magnesium alloy ； Titanium conversion coating process ； Electrochemical impedance spectroscopy ； Corrosion resistance