Magnesium alloy is one of the most light weight metal structure materials. Their potential applied fields include automobile, aerospace and consuming electronics, etc. However, the extensive use of magnesium alloys is limited due to poor corrosion resistance. Micro-arc oxidation (MAO) technique is one of the most favorable method in the surface treatment of magnesium alloys in recent years. It is a surface treatment technique developed from the common anodic oxidation. By use of this technique, a ceramic co...