Effect of Zr and Er on the microstructure, mechanical and electrical properties of Al-0.4Fe alloy

The effect of Zr and Er on the microstructure, electrical conductivity and mechanical properties of Al-0.4Fe alloy was investigated using optical microscope (OM), scanning electron microscope (SEM), electron back-scattered diffraction (EBSD), transmission electron microscope (TEM) and energy dispersive xray spectroscopy (EDS). It is revealed that both of the Zr and Er could inhibit the recrystallization process of Al-0.4 wt %Fe alloy due to the formation of Al3Zr or Al3Er particles. Zr is more recrystallizationresistant than Er due to the preferential precipitation of Al3Zr. Both of the Zr and Er could modify the morphology of Al3Fe particle from needle-like to sphere-like or rod-like, which reduce the negative effect of Al3Fe phase. Zr could significantly refine dendrites of the Al-0.4Fe alloy, while Er shows a negligible effect on dendrite refining due to the delayed formation of Al3Er during solidification. However, the low solubility of Er is beneficial for strength and electrical properties of Al-0.4Fe alloy. In consideration of strength and electrical conductivity, the Al-0.4Fe-0.2Er is selected as the best alloy among the four alloys, which shows a yield strength of 145 MPa, elongation at fracture of 8% and electrical conductivity of 61.2 IACS after cold-rolling. The results provide an insight in design high strength, high conductive aluminum conductor material. (C) 2020 Elsevier B.V. All rights reserved.