Optimization of AZ31B Magnesium Alloy Anodizing Process in NaOH-Na2SiO3-Na2B4O7 Environmental-Friendly Electrolyte

The optimization of NaOH-Na2SiO3-Na2B4O7 electrolyte for the plasma electrolytic oxidation AZ31B magnesium alloy was investigated through orthogonal tests. properties anodized films were evaluated by film thickness, roughness measurements, salt spray tests, scanning electron microscopy (SEM), X-ray diffraction (XRD) and potentiodynamic polarization respectively. tests revealed that optimal formulation comprised NaOH 45 g/L, Na2SiO3 50 Na2B4O7 90 g/L. exhibited most significant effect on while had greatest corrosion resistance. Moreover, electrical parameters also obtained with values current density 1 A /dm2, time 15 min, pulse frequency 200 Hz duty cycle 10%. surface morphology coating formed under conditions uniform compact. Furthermore, phase compositions all samples mainly composed MgO Mg2SiO4. potential, resistance prepared improved remarkably compared substrate.