Effect of minor lanthanum on the microstructures, tensile and electrical properties of Al-Fe alloys

Wheel belt continuous casting and hot extrusion experiments were performed with the Al-0.5wt.%Fe alloys. The effects of minor lanthanum (La) on the microstructures as well as the electrical conductivity and tensile properties have been investigated. The microstructure analyses indicated that minor addition of rare earth element La (500 ppm) not only can achieve the α-Al grain refinement, but also can modify the Al13Fe4 intermetallic phase. The test results of tensile and electrical properties indicated that minor La addition can concurrently enhance the yield strength, ultimate tensile strength, elongation as well as the electrical conductivity of Al-Fe alloys. The improvements of strength, ductility and electrical conductivity are mainly ascribed to the α-Al grain refinement, the modification of Al13Fe4 intermetallic phase and the reduction of the solubility of Fe and Si elements in α-Al, respectively. The minor La addition is a promising approach for altering the microstructures and simultaneously enhancing the tensile properties and electrical conductivity of Al-Fe alloys. This study lays foundation for manufacturing Al-Fe alloys with good tensile and electrical properties.