A chemical conversion coating is provided. The chemical conversion coating is disposed on a surface of a magnesium alloy substrate.As follows:
●A novel route in strongly acidic KMnO4 solution in our study.
●Prepared a relatively-compact KMnO4 conversion coating on Mg alloy.
●Our coating exhibited a better corrosion resistance than the chromate coated.
●The coating could reduce the corrosion area to approximately 3% after 72 h SST.
●A conversion coating with self-healing function on magnesium alloy.

In this study, the main theme is aimed at the improvement of phosphate/permanganate conversion coating. The conversion coating showed better adhesion and less severe crack by virtue of increasing the chemical reactivity and lowering the immersion time, expecting to replace hexavalent chromate conversion coating and reduce the cost. As follows:
●A novel route in strongly acidic KMnO4 solution in our study.
●Prepared a relatively-compact KMnO4 conversion coating on Mg alloy.
●Our coating exhibited a better corrosion resistance than the chromate coated.
●The coating could reduce the corrosion area to approximately 3% after 72 h SST.
●A conversion coating with self-healing function on magnesium alloy.

1. 鎂合金具有諸多優點，如輕量化、易加工、高強度、可防電磁波干擾、能回收再利用等，因而在講求輕、薄、短、小、高質感外觀的時代潮流下，成為鋼鐵、鋁合金、塑膠等製品之替代材料，而國內鎂合金成型產業則大量應用在攜帶式電子儀器外殼上，如筆記型電腦（Note Book）、手機（Cellular Phone）、個人數位助理（PDA，Personal Digital Assistant）等，皆利用鎂合金為主要材料。
2. 囿於鎂合金抗腐蝕能力太差，使得其發展合應用受限，而本技術則採用錳酸鹽化成處理，可有效提昇材料耐蝕性能。