Temperature dependent mechanical properties of zirconium processed by high-pressure torsion at 300 and 77 K

Several structural states of nanostructured zirconium (average grain size of 80–200 nm) were achieved by high pressure torsion (HPT) at temperatures 300 and 77 K, at pressures of 2 and 4 GPa with and without subsequent annealing. Mechanical properties of the nanostructured Zr were investigated by uniaxial compression at temperatures 300, 77 and 4.2 K. Comparison of the strength characteristics, plasticity and strain hardening of the nanostructured and coarse-grained Zr has been carried out. The influences of static recovery occurring after HPT at 77 K, and of twinning, on plasticity and strength of nanostructured Zr have been discussed.