摘要
Strain hardening is a characteristic and important property of metals whereby they are strengthened by the introduction of lattice defects during plastic deformation.In general,a high strain hardening ability is desired,both to ensure the safety of metal components under load and to enable high ductility,allowing the formation of complex shapes.The underlying mechanisms of strain hardening have been extensively studied and are related to an increase in the density of linear lattice defects,i.e.,dislocations,and to the interaction between these defects during the evolution of three-dimensional dislocation structures[1±3].Coarse-grained(CG)metals generally show the highest strain hardening and the best tensile ductility due to the more abundant space for storage of dislocations in various forms of patterning.