Evolution of plasticity, strain-rate sensitivity and the underlying deformation mechanism in Zn–22% Al during high-pressure torsion

 This study explores the evolution of plasticity, strain-rate sensitivity and the underlying deformation mechanism of a Zn–22% Al eutectoid alloy during high-pressure torsion processing. The experiments reveal an optimal torsional straining condition for achieving the largest plasticity; beyond this condition the strain-rate sensitivity decreases and activation volume increases. The results are discussed in terms of changes in the microstructure and the underlying deformation mechanism.