Effect of SMAT preprocessing on MAO fabricated nanocomposite coating

The role of fine microstructure of AZ31B magnesium alloy metallic samples on the morphology, corrosion and wear resistance of the coatings formed by microarc oxidation technique was investigated. Surface nanocrystallisation was carried out through surface mechanical attrition treatment, and a nanocrystalline surface with the grain size of 5-10 nm was obtained. The coatings were studied by optical microscope and SEM images, and corrosion and wear tests were conducted on the samples. Comparison between the maximum and minimum results obtained for the corrosion polarisation resistance indicated 700% increase for different coating conditions. Similar comparison for the wear test results indicated 105% increase in wear resistance for different coating conditions.