Processing of Aluminum-Silicon Wires Treated with ZrB2 Nanoparticles

This research sought to improve the manufacturing process of Al-2wt%Si wires reinforced with ZrB₂ nanoparticles intended for electric and welding applications. The ZrB₂ nanoparticles were mixed and prepared with pure aluminum via high energy ball milling. Afterwards, molten aluminum was inoculated with Al/ ZrB₂ and cast into wire molds. These wires were processed using three annealing processing conditions. First, after solidification the ingot was cold-rolled from 5mm to 1.4 mm diameter wire, which was then annealed  at 400ºC for 5 hours; the wire diameter was then reduced to 1mm. The second process consisted of a 2.5 hour annealing after cold-drawing the wire to 2.8mm diameter first and then to 1.4mm and 1mm. The third processing method was a 1 hour annealing after each area reduction until reaching the desired diameter. The wire specimens were mechanically characterized and their electrical resistivity were measured and compared with pure aluminum, as reference. These results allowed determining the most effective processing method in order to avoid wire damage by excessive work-hardening during fabrication.