A Process for the Direct Hot Extrusion of Hollow Copper Profiles

by Vaitkus, Victor L.

The purpose of this work was to produce copper micro-channel tubing with a uniquely designed lab apparatus. A multi-billet extrusion process was developed using a 250 kN MTS machine and tooling made from superalloys. Elevated friction ring and compression tests were conducted to evaluate the flow stress of UNS C10100 99.99% copper and estimate friction during extrusion conditions. A shear die and shaped die were designed to investigate their performance. Billets were simultaneously extruded forming a single piece of copper micro-channel tubing. Subsequent metallography was conducted to investigate the quality of solid-state welds inherent in the interior walls of the micro-channel tubing. An analytical process model using experimental parameters was developed and validated.