鎂合金在輕金屬中具有多項優點，其良好散熱性及比剛性，同時具生物相容性及可回收性，應用領域廣泛亦兼顧環保訴求，但其活性大易腐蝕，須進行表面處理技術提升耐蝕性及應用性。本研究以微弧氧化製程，使鎂鋁合金生成高抗蝕氧化層，但在微弧擊穿過程中的急劇冷卻和氣體的釋放，造成微孔隙和微裂紋等些許缺陷，使腐蝕介質從局部缺陷滲透至底材而導致腐蝕。為了提升微弧層耐蝕性，本實驗將微弧層進行含氟化物與磷酸鹽封孔處理，使表面生成對鎂合金具保護力的NaMgF3立方顆粒。由表面形貌得知，磷酸鹽可使氟化鎂鈉立方顆粒變小及數量增加，提升顆粒覆蓋率於微弧層表面，搭配電化學量測及鹽霧試驗，證實此製程可提升鎂鋁合金微弧氧化層之耐蝕性。

Magnesium alloy has many advantages among light metals. The material exhibits excellent thermal conductivity and high stiffness-to-weight ratio, is compatible with biological systems and can be recycled. It has many potential uses and prioritizes environmental sustainability. Nevertheless, it exhibits a high susceptibility to corrosion, requiring advancements in surface treatment. In this study, a micro-arc oxidation (MAO) process was used to form a highly corrosion-resistant oxide layer on magnesium-aluminum alloys. Despite this, the rapid cooling of temperature and the subsequent release of gas during the micro-arc breakdown process resulted in the formation of certain defects, such as micropores and microcracks. These defects led to the concentration of the corrosive medium in localized areas. Defects penetrate into the substrate and cause corrosion. In order to improve the corrosion resistance of the micro-arc layer, the micro-arc layer was subjected to phosphate sealing treatment with fluorine-containing compounds to generate NaMgF3 cubic particles on the surface that are protective for magnesium alloys. In this experiment, it is known from the surface morphology that phosphate can make the cubic particles of sodium magnesium fluoride smaller and larger, thereby increasing the particle coverage rate on the surface of the micro-arc layer. Through the use of electrochemical measurement and salt spray tests, it has been shown that this treatment effectively enhances the corrosion resistance of the micro-arc layer in magnesium-aluminum alloys.