알카리 수용액에서 Mg-Al 합금의 양극산화시 전류밀도와 양극산화 시간의 효과

Abstract

The effects on the formation of anodic oxide films on Mg-Al alloy (AZ91) in 1M-NaOH solution was investigated using parameters of current density and time during anodizing. The general tendency has been confirmed that the increase of anodizing time improves the corrosion resistance. It is considered that the formation of anodic oxide film was increased by increasing the applied current and the anodizing time to generate active dissolution reaction. In anodizing at constant current density, passivity potentials shifted to noble direction with increasing current densities. It was confirmed that oxygen quantity in anodic oxide films increased with anodizing time. The compact films above 4 mA/cm2 were formed with the shape of an island in grooves at early stage and then grew with combination of the islands.