Preparation and corrosion resistance of MAO layer/Yb2SiO5 composite coating on Mg alloy

Microarc oxidation (MAO) layer and atmospheric plasma spraying (APS) Yb2SiO5 coat were successfully prepared on Mg alloy to improve the corrosion resistance of the substrate. Bond stability and protection of the composite coating were investigated. The results show that thermal sprayed Yb2SiO5 coat has good compatibility with MAO layer. The composite coating is well bonded with Mg alloy. MAO layer provides a stable interface and high hardness for Mg alloy to bond with Yb2SiO5 coat. The composite coating shows excellent thermal shock resistance. Porous MAO coating is effectively sealed by the melted Yb2SiO5. The MAO layer/Yb2SiO5 composite coating significantly improves the corrosion resistance of Mg alloy.