Effect of Nanocrystalline Layer on Corrosion Behavior of Micro-arc Oxidized AZ31B Mg Alloy

Surface mechanical attrition treatment (SMAT) done on MgAZ31B alloy as the pretreatment process for subsequent micro arc oxidation (MAO) coating on titania nanoparticle suspension. severe plastic deformation creates nanostructured surface that effective on subsequent oxidation. In order to compared nanocrystaline and coarse-grained surface, weight, morphology and potentiodynamic polarization test were examined. Surface morphology was analyzed by scanning electron microscopy. The corrosion resistance of coated samples in a simulated body solution (Ringer's solution) was evaluated. The results showed that the surface mechanical attrition treatment not only changed the porosity and surface morphology of coating but also increased corrosion resistance of MgAZ31B alloy.