AZ61鎂鋁合金表面改質後的腐蝕行為研究

Electrochemical characterization of non-chromate surface treatments on AZ61 magnesium

李文正(Wen-Jen Lee)

指導教授 ： 薛文景

國立臺北科技大學/工程學院/材料及資源工程系研究所/碩士(2009年)

https://doi.org/10.6841/NTUT.2009.00246

摘要

AZ61( 7%Al-93%Mg )鎂鋁合金擁有高比重、反電磁性以及高熱傳導等性質。近期已迅速的應用在3C產業以及航太與汽車零件上，但卻侷限於卑劣的氧化電位，耐蝕性差，故已往普遍均以鉻酸鹽作表面改質。由於在許多國家已明訂法令禁止使用含鉻產品，本實驗利用無鉻電解液下，以化學轉換與陽極處理法增進AZ61抗腐蝕性質，對照EIS (交流阻抗法)電阻阻抗值可比較其處理前後之耐蝕性，並利用數據模擬等效電路說明氧化層之間的關係。AZ61表面生成之薄膜有增加耐蝕性的效果，表示陽極處理能提供較佳的阻抗及較低的電容值。由實驗所得出之腐蝕阻抗值有明顯的增加，並可說明陽極處理生成氧化薄膜與基材間確實擁有良好的附著性。

關鍵字

AZ61鎂鋁合金 ； 陽極處理法 ； 交流阻抗法 ； 模擬等效電路

並列摘要

Surface treatments were applied to AZ61 magnesium alloy (93%Mg-7%Al) within non-chromate environments to develop its anti-corrosion characteristics. The non-chromate process involved chemical conversion using a phosphate and hydrofluoric acid coating, followed by anodizing. The chemical conversion generated good adhesion between the substrates and the anodic film. The anodizing process formed a 50 um-thick film on the surface of the AZ61. Electrochemical properties were obtained using EIS (Electrochemical impedance spectroscopy) analyses to characterize the effects on the treated AZ61. The models of equivalent circuits revealed that the corrosion rate anodized AZ61 was reduced. And passive-film resistance increasing from low to high ohms in evidence.

並列關鍵字

AZ61 magnesium alloy ； non-chromate ； anodizing ； electrochemical impedance spectroscopy ； models of equivalent circuits

參考文獻

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