The effect of hydrostatic extrusion (with a true single-pass strain of e = 0.3–1.2) on the tensile mechanical properties of copper with an ultrafine-grained structure formed by equal-channel angular pressing is investigated. The results show that the optimal combination of the mechanical properties of UFG copper is achieved by hydrostatic extrusion in the strain range e = 0.6–0.9. Depending on the true strain, the ultimate tensile strength and the shear fracture stress of UFG copper can be increased by ≈10 and 40%, respectively. Fracture mechanisms are studied.
Gangalo et al. (Thu,) studied this question.