PREPARATION OF Mg-Al LDH COATING ON AZ31 MAGNESIUM ALLOY UNDER MILD CONDITIONS

Abstract

Magnesium and its alloys are interesting materials but they have low corrosion resistance. Magnesium-aluminium double layered hydroxide (Mg-Al LDH) coatings were prepared on AZ31 alloy by hydrothermal method at 50 degrees C, 70 degrees C and 90 degrees C at different reaction times (3 h, 6 h and 24 h). The coatings were characterized by scanning electron microscope (SEM) with energy dispersive X-ray spectroscope (EDS), Xray diffraction (XRD) and potentiodynamic polarization measurements in 0.15 M NaCI. The optimum conditions for the preparation of the coating included a temperature of 90 degrees C and a reaction time of 24 h, as the coating was composed of Mg-Al LDH and exhibited the highest corrosion resistance.Magnesium and its alloys are interesting materials but they have low corrosion resistance. Magnesium-aluminium double layered hydroxide (Mg-Al LDH) coatings were prepared on AZ31 alloy by hydrothermal method at 50 degrees C, 70 degrees C and 90 degrees C at different reaction times (3 h, 6 h and 24 h). The coatings were characterized by scanning electron microscope (SEM) with energy dispersive X-ray spectroscope (EDS), Xray diffraction (XRD) and potentiodynamic polarization measurements in 0.15 M NaCI. The optimum conditions for the preparation of the coating included a temperature of 90 degrees C and a reaction time of 24 h, as the coating was composed of Mg-Al LDH and exhibited the highest corrosion resistance.