Effect of NaOH Concentration on the Microstructure and Mechanical Properties of the PEO Coatings on Mg-Al3-Zn1 Alloy

Abstract

In this work, the effect of NaOH concentration on the properties of PEO coatings formed on AZ31B Mg alloy is studied. Composition and structure analysis of coatings were carried out by XRD and SEM. From the results, it was found that the number of pores, defects and width of the discharge traces are highly dependent on NaOH concentration. Major phases of the coating identified from XRD were consisted of MgO and Mg2SiO4. The crystallinity of the coatings and magnitude of MgO phase was highly incremented with NaOH concentration. From the Vickers hardness test it was observed that hardness of the coatings prepared in 2g/l of NaOH have the highest values~1050HV, with peak wear resistance values.