플라즈마 전해 산화에 의해 형성된 AZ91 Mg 합금의 산화층에 미치는 전기적 변수의 영향

Abstract

A study was made to study the formation of oxide layer on AZ91 Mg alloy coated by plasma electrolytic oxidation (PEO) process as functions of various electrical parameters such as frequency, current density, and wave form. The formation of coating layer was characterized by scanning electron microscope and X-ray photoelectron spectroscopy for their structural features and constituent phase fractions, which were strongly influenced by electrical parameters. Optimum conditions suitable for coatability including internal stress, dense layer, and high MgO content were suggested. In addition, the corrosion response of the PEO-treated sample was examined by potentiodynamic polarization and electrochemical impedance tests.