Effect of Annealing Treatment on Mechanical Properties of Nanocrystalline alpha-iron: an Atomistic Study
XH Tong and H Zhang and DY Li, SCIENTIFIC REPORTS, 5, 8459 (2015).
Claims are often found in the literature that metallic materials can be nanocrystallized by severe plastic deformation (SPD). However, SPD does not generate a well-defined nanocrystalline (NC) material, which can be achieved by subsequent annealing/recovery treatment. In this study, molecular dynamics (MD) simulation is employed to study the effect of annealing on structure and mechanical properties of cyclic deformed NC alpha-iron, which simulates SPD-processed alpha-iron. It is demonstrated that grain boundaries in the deformed NC alpha-iron evolve to a more equilibrium state during annealing, eliminating or minimizing the residual stress. The annealing treatment increases the system's strength by reducing dislocation emission sources, and improves material ductility through strengthening grain boundaries' resistance to intergranular cracks. The results indicate that the annealing treatment is an essential process for obtaining a well-defined NC structure with superior mechanical properties.
Return to Publications page