Microstructural Evolution and Micro‐Compression in High‐Purity Copper Processed by High‐Pressure Torsion

Pure copper is subjected to severe plastic deformation at room temperature using quasi‐constrained high‐pressure torsion through 1/4 to 10 turns. The evolution of the microstructure is monitored using X‐ray diffraction and electron backscatter diffraction. Specimens are analyzed both before and after micro‐compression of ≈50%. The results show that after 10 turns there is a homogeneous ultrafine‐grained (UFG) microstructure with an average grain size of ≈250 nm and with a simple shear texture. The micro‐compression testing shows that UFG specimens exhibit a better surface quality after compression thereby demonstrating an excellent potential for using UFG copper in micro‐forming.