Evolution of the Microstructure and Mechanical Properties of Copper during the Rolling-ECAP Process

The effect of the new combined rolling-pressing technique of plastic deformation on the structure and mechanical properties of copper has been investigated in this work. The deformation was performed at room temperature and there were three cycles. Rolling-pressing technique was shown to significantly refine the structure of the commercial-purity copper. The strength of the copper workpieces increased by two times after three passes. The ultimate tensile strength and the yield strength increased from 235 to 482 MPa and from 198 to 405 MPa, respectively. The relative elongation and the relative reduction decreased by 8% and 7%, respectively. The ultrafine-grained structure with an average grain size of 2 mu m was revealed to be stable to subsequent annealing up to 150 degrees C.