The powder metallurgy Al has been widely used in the heavy industry, especially in precision technology. Unfortunately, these new materials are problematic in powder metallurgy production and corrosion problems. This research paper aims to study the influence of Mg contents (10, 25, 50, 75, and 90) wt% on microstructure and corrosion behavior on Al–Mg alloy by using powder metallurgy techniques. Al–Mg powder was mixed using a rotation mill with a rotation speed of 120 rpm for 30 min. Then, the mixed powders were compacted at a pressure of 150 MPa. Sintering was done in an argon-controlled atmosphere at a temperature of 500 °C. An optical microscope was used to observe the microstructure of sintered sample; meanwhile, X-ray diffraction (XRD) was used to analyze phase identification. A potentiostat was used to study the corrosion behavior of sintered Al–Mg alloy. The results revealed that Al–90 wt% Mg gives a high corrosion rate.