本研究針對商業用鎂合金AZ31與LZ91的表面腐蝕行為進行研究。透過業界進行多種表面處理，改善鎂合金AZ31與LZ91的抗腐蝕性，並進行電化學量測分析，探討其差異性。表面處理的方式有：電鍍處理、電泳處理、微弧氧化處理、烤漆處理，其中部分試片為包含兩種處理的複合型鍍層。 本研究以OM和SEM對鎂合金AZ31與LZ91及其鍍層作顯微結構觀察，並以SEM配備的EDS判別鍍層的化學組成，另外也使用XPS判別鍍層的化學組成。鑑定合金表面的結晶結構則利用XRD進行分析。合金及其鍍層的電化學性質，則將試片包覆後於室溫浸置於3.5wt% NaCl溶液中，進行動態極化曲線與電化學交流阻抗頻譜的量測。 實驗結果顯示，合金試片經電鍍後，可以有效提升腐蝕電位；經微弧氧化後，有效降低腐蝕速率，及增加腐蝕阻抗；經有機鍍層(電泳處理、烤漆處理)的試片無發生腐蝕現象。 ;The surface corrosion behavior of AZ31 and LZ91 magnesium alloys, and those surface treatments were investigated in this study. The ways of surface treatments included electroplating(EP), electrophoresis(ED), micro-arc oxidation(MAO) and painting. Some specimens were treated by a simultaneous combination of any two ways. Morphologies and composition of bare AZ31 and LZ91 alloys, and coated samples were examined in SEM, EDS and XPS. XRD was also performed to identify the crystal structures of alloy surface. The anticorrosion ability was investigated by potentiodynamic polarization curves and electrochemical impedance spectroscropy (EIS) in 3.5wt% NaCl solutions. The effect of electroplating of the alloy was improved the corrosion potential; The effect of micro-arc oxidation of the alloy was reduced the corrosion rate, and improved corrosion resistance; Then the electrophoresis and painting samples didn’t occur the corrosion.
