Microstructure and tensile properties of ultrafine grained copper processed by equal-channel angular pressing

Equal-channel angular pressing (ECAP) process was applied to a 12 mm × 12 mm × 80 mm billet of pure copper (99.98 wt.%) at room temperature. The shear deformation characteristics, microstructure evolution, and tensile properties were investigated. A combination of high strength (∼420 MPa) and high elongation to failure (∼25%) was achieved after eight ECAP passes at room temperature. The mixing of ultrafine grains (∼0.2 μm) with nanocrystalline grains (∼80 nm) resulted in high tensile strength and ductility.