Influence of Pulse Voltage on the Corrosion Resistance of Al-4.5Mg-3Si Alloy

In this work, the influence of pulse voltage on the corrosion resistance of Al-4.5Mg-3Si alloy was investigated using an electrochemical workstation, scanning electron microscope, x-ray diffraction, and laser scanning confocal microscope. The results have shown that the Mg 2 Si phase in Al-4.5Mg-3Si alloy changed from a long strip to a short rod after electric pulse treatment, which was discontinued in grain boundary, thereby increasing the corrosion resistance of Al-4.5Mg-3Si alloy. Through theoretical calculation and derivation, the approximate quantitative relationship between the nucleation rate and the pulse voltage is obtained, that is, an e-exponential relationship between the square of the nucleation rate and the pulse voltage. Compared with the sample without electric pulse treatment, the average corrosion rate of the treated sample was reduced from 329.4992 to 119.1134 g/m 2 h, the corrosion potential of Al-4.5Mg-3Si alloy increased from − 1.3271 to − 1.2764 V, and the corrosion current density decreased from 1.2726 × 10 −5 to 1.0160 × 10 −5 A cm −2 .