Microstructural evolution and mechanical properties of a Cu–Zr alloy processed by high-pressure torsion

Experiments were conducted on a Cu–0.1% Zr alloy in order to examine the evolution of hardness and microstructure after processing by high-pressure torsion. Disks were pressed through different numbers of revolutions up to a maximum of 10 turns using an applied pressure of 6.0 GPa. It is shown that there is a gradual evolution in both the hardness and the microstructure with increasing numbers of turns. After 5 and 10 turns there is a high degree of hardness homogeneity and the microstructure consists of well-defined equiaxed grains. The measured grain size after 5 turns was ∼180 nm in the peripheral region of the disk. Tensile testing at 673 and 723 K after processing through 5 and 10 turns showed a maximum elongation to failure of ∼280% at 723 K using a strain rate of 1.0 × 10−4 s−1.