The corrosion behaviour of PM Al composite will be affected by the presence of alloying element and reinforcing phase in the composite. This study focused on magnesium and alumina Saffil™ short fibres reinforcement affected to corrosion behaviour of PM AMCs in 3.5wt% NaCl. PM Al composite and PM Al-Mg composite were fabricated from flaky aluminium powder, 2wt% granular magnesium and 15wt% alumina Saffil™ short fibres. The corrosion testing was done using potentiostat Gamry G300 to create Tafel plot and polarization curve. The corrosion effects were analyse using scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). From experiment, pitting was localized surrounding the magnesium constituents which occur randomly throughout the surface of PM Al-Mg composite. XRD analysis revealed that aluminum oxide (δ-Al Al1.67O4), aluminium hydroxide (Al (OH)3) and aluminium oxide (α-Al2O3) phases were detected in oxide film. The corrosion current density (Icrit) of PM Al composite is lower than PM Al-Mg composite which is 2.0 x 10-1 A/cm2 and 4.0 x10-1 A/cm2, respectively. Magnesium is used as inhibitor in corrosion behaviour of PM Al-Mg composite have been changed and protected with a stable formation of oxide film. The corrosion resistance of PM Al-composite was decreased with the presence of alumina Saffil™ short fibres in composite due to discontinuities in oxide film provided the corrosion initiated in sample.
