High-strength pure bulk aluminum was fabricated by mechanical alloying and press forming, and its electrochemical properties and corrosion behavior in 0.5 M NaCl solution were investigated by means of potentiodynamic polarization and electrochemical impedance spectroscopy. Microstructural characterizations revealed that in addition to a Vickers hardness of 144 HV, the refined grain (0.2–1 μm) enhanced tensile and yield strengths to 560 and 520 MPa, respectively. Electrochemical data demonstrated that pure Al exhibited higher corrosion resistance than its alloys AA5083 and AA2024. Ultrafine, compact structure and homogeneous composition ensured a dense film formation during passivation. Moreover, the defect-free passive film protects the substrate by providing a high barrier against the aggressive chloride ions.