Effect of electromagnetic stirring current on microstructure and corrosion resistance of Al–Sn Alloy

Abstract

Al-Sn bearing alloys were prepared with different electromagnetic stirring (EMS) currents. Electrochemical and immersion corrosion experiments were carried out on the samples. Optical microscope, SEM, EDS, and XPS were used to characterize the samples to study the effect of stirring current on the microstructure and corrosion properties of the alloy. The results show that the structure of the sample without EMS is all dendrites. With the increase of stirring current, the number of primary phase agglomerates is less and the grain size decreases. When the stirring parameter is 60A, 20Hz, the grain size is the most round and small, and the stirring effect is the best. In the later stage of immersion, the corrosion product film formed on the surface is more dense and uniform, which can effectively block the erosion of ions in the solution. The equivalent circuit fitting calculation shows that the R total value is the largest, which is 1.79 × 106 Ω·cm2, and the corrosion resistance is the best.