本研究是藉由電化學沉積MgO鍍層在純鎂基材上應用於防制腐蝕。經由X光繞射(XRD)分析與SEM觀察，顯示經由電解反應可形成Mg(OH)2鍍層，再經370℃退火可形成MgO，其中Mg(OH)2鍍層結晶取向與施加的電壓有關，主要是由於在較負的電壓下，會有較多的OH-離子產生，造成鍍層會有(001)的從優取向。因此我們可以藉由不同的電位來控制Mg(OH)2鍍層的表面形貌。經由電化學極化分析與浸置實驗，可知沉積電位-2.0 V，鍍膜時間2400s，400℃退火處理有較均勻致密的MgO鍍層，且在3.5wt %的NaCl溶液中腐蝕電流由114降低到5.82 μA/cm2，鈍化區域從-1.72到 -1.57 V(Ag/AgCl)，可有效改善純鎂的抗蝕性而與微弧氧化法(MAO)性能相當。 The electrolytic MgO coating on Mg alloy has been carried out in 0.1 M Mg(NO3)2 aqueous solution to improve its corrosion resistance. By X-ray diffraction (XRD), and scanning electron microscopy (SEM),the as-deposited film was Mg(OH)2 formed by the electrolysis, (Mg2+‧2H2O → Mg(OH)2 + H2) , and finally condensed into MgO at 370 ℃. It was also found that the crystal orientation and morphology of Mg(OH)2 was linked to the applied voltage. The more negative the applied voltage and the more the OH- concentration was, finally resulting in the more (001) preferred orientation and various related surface appearances. Therefore, the controllable fabrication of highly dense and uniform Mg(OH)2 film could be carried out by tuning deposition potential. An optimum process conducted at -2.0 V(Ag/AgCl) for 2400s and annealed at 400 ℃ was suggested to derive a more uniform and densified MgO protective film, revealing corrosion current density reduced from 114 down to 5.82 μA/cm2 and a passivation region from -1.72 to -1.57 V(Ag/AgCl) in 3.5 wt% NaCl aqueous solution, comparable with micro-arc oxidation.