Micro-Arc Oxidation Phenomenon for Producing Coatings of AZ31B Mg Alloy Using Na 3 PO 4 with Varying KOH Concentrations and Voltages: A Study.

Complex salt solution systems are commonly used as electrolytes for microarc oxidation (MAO). To investigate the MAO phenomenon in simple electrolytes and evaluate the efficacy of MAO coatings, an Na₃PO₄ monosalt solution was used as the MAO electrolyte. In this study, the effects of the voltage and Na₃PO₄ concentration on the spark discharge phenomenon, thickness, roughness, and corrosion resistance of the coatings were investigated. The results showed that MAO coatings were effectively synthesised at high concentrations and voltages. Furthermore, the addition of KOH to the Na₃PO₄ monosalt solution resulted in discernible spark discharge and improved the corrosion resistance of the coatings. Thus, an MAO coating can be efficiently prepared using Na₃PO₄ solution as the electrolyte. In addition, the addition of KOH to the Na₃PO₄ monosalt solution reduced the voltage required for coating formation and enhanced the corrosion resistance of the coating. [ABSTRACT FROM AUTHOR]