WANG Huan, LIU Xiangdong, ZHANG Yaping, WU Di, CHEN Weidong,LI Yuantao

(School of Materials Science and Engineering, Inner Mongolia University of Technology, Hohhot 010051)

Abstract:The compositions of electrolyte play an important role in the formation of films in microarc oxidation proces s.The effect of the content of Ce(SO₄)₂ in Na₂SiO₃ electrolyte on the characteristics of microarc oxidation films on AZ91D alloy was investigated in this study. The thickness of films was measured. The compositions of phase and the microstructures of the ceramic coatings were analyzed by XRD and SEM. The results show that the thickness of the ceramic coatings increases at first, but afterwards reduces with the increase of the content of Ce(SO₄)₂from 0.1 to 0.3 g/L. The diameter of pores and microcracks on the surface of ceramic coatings reduces with the increasing of the content of Ce(SO₄)₂. The ceramic coatings are smooth and uniform and are composed of MgO and Mg₂SiO₄.

Keywords:AZ91D, microarc oxidation, electrolyte, Ce(SO₄)₂, ceramic coating