Corrosion Behavior of Different Coatings Prepared on the Surface of AZ80 Magnesium Alloy in Simulated Body Fluid

A laser shock peening (LSP) layer, a micro-arc oxidation (MAO) bio-coating, and an LSP/MAO bio-composite coating were fabricated on the surface of AZ80 magnesium (Mg) alloy. The LSP-, MAO-, and LSP/MAO-treated samples were subjected to a dynamic immersion test for 24 h in simulated body fluid (SBF) with a flow rate of 1 mL/s. The corrosion evolution behavior of the three samples in SBF solution was investigated by electrochemical tests at 0.5, 2, 4, 12, 16, and 24 h during the dynamic immersion. The results indicated that the three surface-treated samples exhibited different corrosion behaviors at different degradation stages. The LSP/MAO sample showed the best corrosion resistance. The anti-corrosion effect of the LSP nanocrystalline layer on the substrate material during dynamic degradation is discussed.