Effect of Rare Earth La on the Microstructure, Mechanical Properties, Electrical Conductivity, and Corrosion Behavior of an As-Cast Al-0.5 wt%Fe Aluminum Alloy

The effect of La content on the microstructure, mechanical properties, electrical conductivity and corrosion resistance of as-cast Al-0.5 wt%Fe alloys was evaluated. The results showed that the La addition can promote the refinement of the alpha-Al grains and modify the Fe-containing phases. The addition of La has limited effect on the strength of Al-0.5 wt%Fe alloy. The elongation and electrical conductivity increases first and then decreases with the increase of La content in Al-0.5 wt%Fe alloy. When the addition of La is 0.10 wt% in Al-0.5 wt%Fe alloy, the maximum elongation and electrical conductivity are about 46.56% and 59.59%IACS, respectively. Polarization curves indicated that the corrosion current density (Icorr) and corrosion rate decrease with the increase of La content. Electrochemical impedance spectroscopy (EIS) tests also presented that the impedance is increased with the increase of the La content. Therefore, the addition of La improved the corrosion resistance of the Al-0.5 wt%Fe alloy.