MOLD FILLING ABILITY AND HOT CRACKING SUSCEPTIBILITY OF AL-FE-NI ALLOYS FOR HIGH CONDUCTIVITY APPLICATIONS

Abstract

Newly developed high conductivity Al-Fe-Ni alloys are expected to be used for various electronic and electrical applications instead of conventional low conductivity Al casting alloys. In this research, influence of Ni content on the mold filling ability and hot cracking susceptibility of Al-Fe-Ni alloys was investigated. The cast microstructure of Al-0.5Fe-xNi alloys mainly consists of primary aluminum and 2nd phases, and the kind of the 2nd phases is dependent on the Ni content. As the Ni content was increased, Al3Ni phase became dominant as the 2nd phase. Although the Ni additions reduced the conductivity a little, Al-0.5Fe-xNi alloys with nickel ranging from 0.5 to 2% showed significantly higher electrical conductivity than conventional Al-Si based alloys. The mold filling ability measured by fluidity serpentine test of Al-Fe-Ni alloys decreased significantly when more than 1%Ni was added. The mold filling ability measured by using a pressure die-casting method showed the similar results with respect to the Ni content. Meanwhile, hot cracking susceptibility was increased remarkably when more than 0.5%Ni was added.