Intermediate annealing of pure copper during cyclic equal channel angular pressing

The influence of proper intermediate heat treatment on mechanical properties of the ultrafine-grained copper processed by ECAP was investigated. The tensile experiment showed that the ultimate strength is elevated about 50 MPa compared with the sample without intermediate annealing. X-ray diffraction peak broadening analyses have demonstrated that the coherent domain size decreased in some ways with the intermediate annealing, which is the reason for the increase in strength of the copper specimen.