Microstructure and Mechanical Properties of Pure Copper Wire Produced by Shear Assisted Processing and Extrusion

The shear assisted processing and extrusion (ShAPE) process can consolidate powdered materials and simultaneously extrude wire or tube with improved properties. We successfully produced copper wire extrusions from powder and solid materials for the first time. The extrusion pressure in the ShAPE process is at least ten times less than that required for conventional extrusion. We used optical microscopy to inspect and validate the integrity of extrudates, revealing that the microstructure was refined and dynamically recrystallized to equiaxial grains. Compared with annealed copper wire, ShAPE-processed wire showed 80% higher yield strength, 15% higher ultimate tensile strength, and 20% higher ductility. These results were correlated with refined grain size and substructuring observed via electron backscatter diffraction analysis and transmission electron microscopy.