Die Soldering of Al-Fe-Ni Alloys for Thermal and Electrical Applications

The modern automotive sector has an increasing need for lightweight parts with high electrical and thermal conductivity and high castability. Castability is a wide combination of properties including but not limited to hot tear susceptibility, die soldering, and fluidity. Alloys based on the Al-Fe-Ni system offer high thermal and electrical conductivity with good castability. The die soldering of Al-Fe-Ni alloys was assessed by submerging pure Fe wires into Al-Ni-Fe melts for an extended period of time and measuring Fe wire material loss. Hot tear susceptibility was assessed by pouring the Al-Fe-Ni alloys into a specially designed steel mold that restricts shrinkage to promote the formation of hot tears. An Al-Fe-Ni alloy with Mg and Si addition demonstrated a high as cast electrical conductivity of 47 IACS% with a minimal die soldering material loss rate of 0.8 mg/mm and low hot tear susceptibility. A typical 319 cast Al alloy had an electrical conductivity of 25 IACS%, a die soldering material loss rate of 3.5 mg/mm, and a higher hot tear susceptibility. The Al-Fe-Ni alloys show potential to produce highly castable, highly conductive parts for transportation applications.