Castable Aluminum Alloys containing Nickel and Iron with High Electrical and Thermal Conductivity
Modern lightweighting applications require Al alloys with high electrical and thermal conductivity, moderate strength and high castability that cannot be met using traditional cast alloys. Potential alternatives include Al-Fe, Al-Ni, and Al-Fe-Ni-Mg-Si alloying systems. The binary alloys consisted of a pure Al matrix with Al3Ni and Al6Fe intermetallic phases. The cast parts also demonstrated moderate microhardness and high electrical and thermal conductivity. The Al-Fe-Mg-Si multicomponent alloys contained additional intermetallic phases including branched α-AlFeSi, rounded Al9FeNi, and Mg2Si. The multicomponent alloys demonstrated comparable hot tearing susceptibility and fluidity to Al A380, an Al-Si cast Al alloy. Additionally, the multicomponent alloying system could produce cast parts with half the microhardness and double the electrical conductivity of Al A380. Artificially aging the multicomponent alloys improved the electrical conductivity approximately 8 %IACS. The Al-Fe-Mg-Si alloy system presents a viable and versatile alternative with the potential to produce parts with high conductivity and complex geometries.