Semi-Continuous Friction Extrusion of Aluminum Conductors

This study presents the first demonstration of semi-continuous friction extrusion for wire manufacturing using a sequential back-to-back billet loading process on the shear assisted processing and extrusion (ShAPE^TM) platform. By leveraging a controlled extrusion setup, billet remnants (2–12 mm) adhere to the die, enabling metallurgical bonding between consecutive billets within the container. This ensures defect-free interfaces and maintains uniform electrical properties along the extruded wire. Electrical conductivity variations in the extruded wire at the billet transition regions are minimal. The temperature coefficient of resistance (TCR) at the transition region in the extrudate remains within measurement uncertainty, confirming the robustness of the process. This method enables flexible and scalable production of long wires using friction extrusion by precluding single runs requiring large feedstock volumes. It opens new opportunities for large-scale wire manufacturing in different applications including but not limited to power transmission lines, additive manufacturing feedstocks, and electromagnetic coil windings.